test(deployment): cover Remote Host Download to… wiring (#2763)

Covers Download to… in the Remote Host view: the Project view selection preselects the folder picker (its parent folder for a selected file), cancelling the picker downloads nothing, and the chosen folder receives the remote paths.

Co-authored-by: GGVidal <[email protected]>

.oxfmtrc.json

@@ -12,6 +12,7 @@
     "src/editor/core/cm/angular/parser*.ts",
     "src/editor/core/cm/jsp/parser*.ts",
     "src/editor/core/cm/astro/parser*.ts",
+    "src/editor/core/cm/django/parser*.ts",
     "plugins/themes.md",
     "pnpm-lock.yaml",
     "**/*.toml",

Cargo.lock

@@ -4618,6 +4618,7 @@ name = "ide-lsp"
 version = "0.1.42"
 dependencies = [
  "dunce",
+ "encoding_rs",
  "futures",
  "globset",
  "ide-core",

crates/ide-agent/src/acp/discover.rs

@@ -0,0 +1,102 @@
+//! A short-lived ACP session to learn models, effort levels and other config options
+//! before the user's first task (Cursor and other ACP agents do not expose these in
+//! `initialize` alone).
+
+use super::{Conn, Dialect};
+use crate::config;
+use crate::model::AgentConfigOption;
+use crate::provider::ProviderSpec;
+use crate::{Shared, client_info};
+use parking_lot::Mutex;
+use serde_json::{Value, json};
+use std::sync::Arc;
+use std::time::Duration;
+
+const DISCOVER_TIMEOUT: Duration = if cfg!(test) { Duration::from_secs(3) } else { Duration::from_secs(120) };
+
+/// Opens `session/new`, reads `configOptions`, and records per-model `thought_level` choices.
+pub(crate) async fn run(shared: &Arc<Shared>, spec: &ProviderSpec) -> Result<(), String> {
+    let root = shared.paths.project_root.clone();
+    let launch = spec.clone();
+    let launch = tokio::task::spawn_blocking({
+        let root = root.clone();
+        move || launch.resolve_for_launch(&root)
+    })
+    .await
+    .map_err(|e| e.to_string())?;
+    let cwd = dunce::canonicalize(&root).unwrap_or(root);
+    let stderr: Arc<Mutex<Vec<String>>> = Arc::default();
+    let lines = stderr.clone();
+    let on_stderr: Box<dyn Fn(String) + Send + Sync> = Box::new(move |l| lines.lock().push(l));
+    let client = Dialect::wrap(Arc::new(ide_jsonrpc::NoopHandler));
+    let peer = (shared.connector)(&launch, &cwd, client.clone(), on_stderr)
+        .map_err(|e| format!("Couldn't start {} (`{}`): {e}", launch.name, launch.command))?;
+    let conn = Conn::new(peer.clone(), client);
+    let work = async {
+        conn.initialize(&client_info()).await.map_err(|e| e.to_string())?;
+        let cwd_s = cwd.to_string_lossy().into_owned();
+        // No project MCP during discovery: Cursor can spend a long time spawning servers.
+        let new: Value = conn
+            .request("session/new", json!({ "cwd": cwd_s, "mcpServers": [] }), None)
+            .await
+            .map_err(|e| e.to_string())?;
+        let mut options = config::options_of(&new);
+        config::add_client_options(&launch.id, &mut options);
+        let model_option = options.iter().find(|o| o.category.as_deref() == Some("model"));
+        let effort = levels_for_model_from_slice(&options);
+        let levels: Vec<(String, Vec<AgentConfigOption>)> = match (model_option, effort) {
+            (Some(model), Some(effort)) if !model.values.is_empty() => {
+                model.values.iter().map(|v| (v.value.clone(), effort.clone())).collect()
+            }
+            (Some(model), Some(effort)) => model.current.clone().map(|m| vec![(m, effort)]).unwrap_or_default(),
+            _ => Vec::new(),
+        };
+        let option_ids: Vec<_> = options.iter().map(|o| o.id.as_str()).collect();
+        tracing::info!(
+            "agent {}: settings discovery got {} config option(s) {:?}, {} model effort list(s)",
+            launch.id,
+            options.len(),
+            option_ids,
+            levels.len()
+        );
+        shared.remember_discovered(&launch.id, &options, &[], &levels);
+        Ok::<(), String>(())
+    };
+    let result = tokio::time::timeout(DISCOVER_TIMEOUT, work).await;
+    peer.kill();
+    match result {
+        Ok(Ok(())) => Ok(()),
+        Ok(Err(e)) => Err(match stderr.lock().last() {
+            Some(line) => format!("{e}: {line}"),
+            None => e,
+        }),
+        Err(_) => {
+            let tail = stderr.lock().join("\n");
+            if tail.is_empty() {
+                Err("the agent did not answer in time".into())
+            } else {
+                Err(format!("the agent did not answer in time:\n{tail}"))
+            }
+        }
+    }
+}
+
+fn is_thought_level(o: &AgentConfigOption) -> bool {
+    o.category.as_deref() == Some("thought_level")
+        || matches!(o.id.as_str(), "effort" | "reasoning_effort" | "thinking" | "reasoning")
+}
+
+fn levels_for_model_from_slice(options: &[AgentConfigOption]) -> Option<Vec<AgentConfigOption>> {
+    let levels: Vec<_> = options
+        .iter()
+        .filter(|o| is_thought_level(o))
+        .cloned()
+        .map(|mut o| {
+            if o.category.as_deref() != Some("thought_level") {
+                o.category = Some("thought_level".into());
+            }
+            o
+        })
+        .collect();
+    (!levels.is_empty()).then_some(levels)
+}

crates/ide-agent/src/acp/mod.rs

@@ -14,6 +14,7 @@
 //! - Agent → client ([`Dialect`]): `session/update`s are normalized ([`normalize`]) and
 //!   permission requests get the v1 `toolCall`.
 
+pub(crate) mod discover;
 mod normalize;
 
 use ide_jsonrpc::{Handler, Peer, RpcError, codes};
@@ -57,6 +58,9 @@ fn client_capabilities() -> Value {
         "terminal": false,
         // Subagents as sessions of their own (ACP subagents RFD; v2 baseline).
         "subagents": {},
+        // Cursor exposes model parameters (e.g. Composer `fast`) as separate config options
+        // only when the client advertises this flag (undocumented Cursor ACP extension).
+        "_meta": { "parameterizedModelPicker": true },
     })
 }
 

crates/ide-agent/src/acp/tests.rs

@@ -93,9 +93,81 @@ fn the_negotiating_request_carries_both_versions() {
     assert!(p["capabilities"].is_object());
     assert_eq!(p["clientCapabilities"]["subagents"], json!({}));
     assert_eq!(p["clientCapabilities"]["terminal"], false);
+    assert_eq!(
+        p["clientCapabilities"]["_meta"]["parameterizedModelPicker"], true,
+        "Cursor and similar agents need parameterized model options (e.g. fast on/off)"
+    );
     // What we sent in the capture is what claude-agent-acp negotiated v2 and v1 from.
-    let sent = &frames(TURN, "out")[0]["params"];
-    assert_eq!(sent["clientCapabilities"], p["clientCapabilities"]);
+    let sent = frames(TURN, "out")[0]["params"]["clientCapabilities"].clone();
+    let mut expected = sent;
+    expected["_meta"] = p["clientCapabilities"]["_meta"].clone();
+    assert_eq!(expected, p["clientCapabilities"]);
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn discovery_reads_effort_and_fast_from_session_new_then_stops_the_agent() {
+    #[derive(Default)]
+    struct DiscoveryAgent {
+        peer: std::sync::OnceLock<Peer>,
+        calls: parking_lot::Mutex<Vec<(String, Value)>>,
+    }
+    impl Handler for DiscoveryAgent {
+        fn on_notification(&self, _: &str, _: Value) {}
+        fn on_request(&self, method: &str, params: Value) -> Result<Value, (i64, String)> {
+            self.calls.lock().push((method.to_owned(), params));
+            match method {
+                "initialize" => Ok(json!({
+                    "protocolVersion": 1,
+                    "agentCapabilities": { "loadSession": true }
+                })),
+                "session/new" => Ok(json!({
+                    "sessionId": "discover",
+                    "configOptions": [
+                        {"id": "model", "category": "model", "type": "select", "currentValue": "m1",
+                         "options": [{"value": "m1", "name": "One"}, {"value": "m2", "name": "Two"}]},
+                        {"id": "effort", "type": "select", "currentValue": "medium",
+                         "options": [{"value": "low"}, {"value": "medium"}, {"value": "high"}]},
+                        {"id": "fast", "type": "select", "currentValue": "false",
+                         "options": [{"value": "false", "name": "Off"}, {"value": "true", "name": "On"}]}
+                    ]
+                })),
+                _ => Ok(json!({})),
+            }
+        }
+    }
+    let agent = Arc::new(DiscoveryAgent::default());
+    let tmp = tempfile::tempdir().unwrap();
+    let agent_for_connector = agent.clone();
+    let connector: crate::Connector = Arc::new(move |_, _, client, _| {
+        let (ca, cb) = tokio::io::duplex(1 << 20);
+        let (car, caw) = tokio::io::split(ca);
+        let (cbr, cbw) = tokio::io::split(cb);
+        let agent_peer = Peer::connect_framed(cbr, cbw, agent_for_connector.clone(), Framing::Lines);
+        let _ = agent_for_connector.peer.set(agent_peer);
+        Ok(Peer::connect_framed(car, caw, client, Framing::Lines))
+    });
+    let mgr = crate::AgentManager::with_connector(
+        crate::AgentPaths {
+            project_root: tmp.path().to_path_buf(),
+            store_dir: tmp.path().join("store"),
+            worktrees_dir: tmp.path().join("worktrees"),
+            models_file: tmp.path().join("models.json"),
+            custom_agents_dir: None,
+            home_dir: None,
+        },
+        tokio::runtime::Handle::current(),
+        connector,
+    );
+    mgr.commands("cursor", None).await.unwrap();
+    let calls = agent.calls.lock();
+    assert_eq!(calls.iter().map(|(m, _)| m.as_str()).collect::<Vec<_>>(), ["initialize", "session/new"]);
+    assert_eq!(calls[1].1["mcpServers"], json!([]));
+    let cursor = mgr.providers().into_iter().find(|p| p.id == "cursor").unwrap();
+    let fast = cursor.config.iter().find(|o| o.id == "fast").expect("fast option");
+    assert_eq!(fast.category.as_deref(), Some("model_config"));
+    assert_eq!(fast.current.as_deref(), Some("false"));
+    assert!(cursor.thought_levels.contains_key("m1") && cursor.thought_levels.contains_key("m2"));
+    assert!(cursor.thought_levels["m1"].iter().any(|o| o.category.as_deref() == Some("thought_level")));
 }
 
 #[test]

crates/ide-agent/src/config.rs

@@ -107,7 +107,15 @@ pub(crate) fn parse_options(options: &Value) -> Vec<AgentConfigOption> {
             Some(AgentConfigOption {
                 name: str_of(o, "name").unwrap_or_else(|| id.clone()),
                 description: str_of(o, "description"),
-                category: str_of(o, "category").or_else(|| matches!(id.as_str(), "model" | "mode").then(|| id.clone())),
+                category: str_of(o, "category").or_else(|| {
+                    matches!(id.as_str(), "model" | "mode")
+                        .then(|| id.clone())
+                        .or_else(|| {
+                            matches!(id.as_str(), "effort" | "reasoning_effort" | "thinking" | "reasoning")
+                                .then(|| "thought_level".into())
+                        })
+                        .or_else(|| matches!(id.as_str(), "fast").then(|| "model_config".into()))
+                }),
                 current: str_of(o, "currentValue"),
                 values,
                 via: AgentConfigVia::Option,
@@ -333,6 +341,21 @@ mod tests {
         assert!(bypass_approvals(&url_mode));
     }
 
+    #[test]
+    fn effort_and_fast_categories_are_inferred_from_ids() {
+        let c = options_of(&json!({
+            "configOptions": [
+                {"id": "effort", "type": "select", "currentValue": "high",
+                 "options": [{"value": "low"}, {"value": "high"}]},
+                {"id": "fast", "type": "select", "currentValue": "false",
+                 "options": [{"value": "false", "name": "Off"}, {"value": "true", "name": "On"}]}
+            ]
+        }));
+        assert_eq!(c.len(), 2);
+        assert_eq!(c[0].category.as_deref(), Some("thought_level"));
+        assert_eq!(c[1].category.as_deref(), Some("model_config"));
+    }
+
     #[test]
     fn command_sources_in_updates_and_stored_tasks() {
         let update = json!({"availableCommands": [

crates/ide-agent/src/lib.rs

@@ -16,6 +16,7 @@ mod model;
 mod native;
 mod provider;
 pub mod registry;
+pub mod security;
 mod skills;
 mod timeline;
 mod worktree;
@@ -39,6 +40,9 @@ use std::time::Duration;
 /// Receives the events of one project's tasks.
 pub type AgentSink = Arc<dyn Fn(AgentEvent) + Send + Sync>;
 
+/// Returns the active command execution security policy for the project.
+pub type SecurityHook = Arc<dyn Fn() -> ide_core::settings::AgentSecuritySettings + Send + Sync>;
+
 /// Entry changes are batched for this long before they are sent.
 const FLUSH_DELAY: Duration = Duration::from_millis(40);
 /// Updates that arrive this late after `session/load` returns are still replayed history.
@@ -102,6 +106,7 @@ struct Shared {
     runtime: tokio::runtime::Handle,
     connector: Connector,
     sink: RwLock<Option<AgentSink>>,
+    security: RwLock<Option<SecurityHook>>,
     known: Mutex<HashMap<String, Known>>,
     providers: RwLock<Vec<provider::ProviderSpec>>,
     /// Last probe of each provider.
@@ -177,9 +182,15 @@ impl Shared {
                     let shared = self.clone();
                     // Keep the lookup alive if a composer unmounts while it is waiting.
                     self.runtime.spawn(async move {
-                        if let Ok(found) =
-                            native::claude::discover(spec.clone(), shared.paths.project_root.clone()).await
-                        {
+                        tracing::info!("agent {}: settings discovery started", spec.id);
+                        let discovered = if spec.driver == provider::Driver::Acp {
+                            acp::discover::run(&shared, &spec).await.map(|_| None)
+                        } else if spec.driver == provider::Driver::Claude {
+                            native::claude::discover(spec.clone(), shared.paths.project_root.clone()).await.map(Some)
+                        } else {
+                            return;
+                        };
+                        if let Ok(Some(found)) = discovered {
                             let commands =
                                 config::commands_of(&json!({ "availableCommands": found.commands }), &spec.id);
                             let options = config::options_of(&json!({ "configOptions": found.options }));
@@ -198,6 +209,8 @@ impl Shared {
                                 shared.remember_discovered(&spec.id, &options, &commands, &levels);
                             })
                             .await;
+                        } else if let Err(e) = discovered {
+                            tracing::info!("agent {}: settings discovery failed: {e}", spec.id);
                         }
                         let _ = done.send(true);
                     });
@@ -220,12 +233,17 @@ impl Shared {
     fn knows_all_levels(&self, provider: &str) -> bool {
         let cache = self.known.lock();
         let Some(known) = cache.get(provider) else { return false };
-        known
+        let models: Vec<&str> = known
             .config
             .iter()
             .filter(|o| o.category.as_deref() == Some("model"))
-            .flat_map(|o| &o.values)
-            .all(|v| known.thought_levels.contains_key(&v.value))
+            .flat_map(|o| o.values.iter().map(|v| v.value.as_str()))
+            .collect();
+        // No advertised models yet: nothing to attach effort levels to.
+        if models.is_empty() {
+            return false;
+        }
+        models.iter().all(|id| known.thought_levels.contains_key(*id))
     }
 
     fn root_key(&self) -> String {
@@ -434,6 +452,7 @@ impl AgentManager {
             runtime,
             connector,
             sink: RwLock::new(None),
+            security: RwLock::new(None),
             known: Mutex::new(known),
             providers,
             probes: Mutex::new(HashMap::new()),
@@ -477,6 +496,11 @@ impl AgentManager {
         tasks
     }
 
+    /// Sets the callback used to read the active command execution security policy.
+    pub fn set_security_hook(&self, hook: SecurityHook) {
+        *self.shared.security.write() = Some(hook);
+    }
+
     /// The agents (custom ones re-read), whether each is installed, and what they offered last time.
     pub fn providers(&self) -> Vec<AgentProvider> {
         let specs = provider::load(self.shared.paths.custom_agents_dir.as_deref());
@@ -501,7 +525,9 @@ impl AgentManager {
             let new = specs.iter().find(|p| &p.id == id);
             matches!((old, new), (Some(a), Some(b)) if a.command == b.command && a.args == b.args && a.env == b.env)
         });
-        *prev = specs;
+        *prev = specs.clone();
+        drop(probes);
+        drop(prev);
         list
     }
 
@@ -522,6 +548,30 @@ impl AgentManager {
         provider::set_builtin_env(&dir, id, env)
     }
 
+    /// Saves a new custom ACP agent through its agent file.
+    pub fn save_custom_agent(&self, input: CustomAgentInput) -> IdeResult<()> {
+        let Some(dir) = self.shared.paths.custom_agents_dir.clone() else {
+            return Err(IdeError::unavailable("there is no custom agents directory"));
+        };
+        provider::save_custom(&dir, &input)
+    }
+
+    /// Removes a custom agent's file (registry installs go through `registry_remove`).
+    pub fn remove_custom_agent(&self, id: &str) -> IdeResult<()> {
+        let Some(dir) = self.shared.paths.custom_agents_dir.clone() else {
+            return Err(IdeError::unavailable("there is no custom agents directory"));
+        };
+        provider::remove_custom(&dir, id)
+    }
+
+    /// Imports a JetBrains `acp.json` file's `agent_servers` entries as custom agents.
+    pub fn import_acp_agents(&self, text: &str) -> IdeResult<Vec<AcpImportOutcome>> {
+        let Some(dir) = self.shared.paths.custom_agents_dir.clone() else {
+            return Err(IdeError::unavailable("there is no custom agents directory"));
+        };
+        provider::import_acp(&dir, text)
+    }
+
     /// Re-reads configured/installed agents, drops cached probes, and notifies subscribers.
     pub fn reload_providers(&self) {
         let specs = provider::load(self.shared.paths.custom_agents_dir.as_deref());
@@ -552,10 +602,16 @@ impl AgentManager {
         let mut offered = offered;
         if task.is_none()
             && (offered.is_empty() || !self.shared.has_config(&provider) || !self.shared.knows_all_levels(&provider))
-            && let Some(spec) = self.shared.spec(&provider).filter(|s| s.driver == provider::Driver::Claude)
+            && let Some(spec) = self
+                .shared
+                .spec(&provider)
+                .filter(|s| matches!(s.driver, provider::Driver::Claude | provider::Driver::Acp))
         {
+            let claude = spec.driver == provider::Driver::Claude;
             self.shared.fetch_settings(spec).await;
-            offered = self.shared.known_commands(&provider);
+            if claude {
+                offered = self.shared.known_commands(&provider);
+            }
         }
         for &(name, description) in builtin_commands(&provider) {
             if !offered.iter().any(|c| c.name == name) {
@@ -888,14 +944,38 @@ impl AgentManager {
             }
             o.clone()
         };
+        let previous = target.current.clone();
+        // Cursor's `session/set_config_option` (Fast, effort) can take seconds. Show the
+        // choice first so the switch and slider move immediately.
+        apply_config_choice(&task, option, &value);
+        task.persist();
+        task.emit_task();
+
         let live = task.live.lock().clone().filter(|l| !l.peer.is_closed());
         let mut model_options =
-            target.category.as_deref() != Some("model") || target.current.as_deref() == Some(value.as_str());
+            target.category.as_deref() != Some("model") || previous.as_deref() == Some(value.as_str());
         if let Some(live) = live.filter(|_| option != config::CURSOR_APPROVAL) {
             let (method, mut params) = config::set_request(&target, &value);
             params["sessionId"] = json!(live.session);
-            let reply: Value =
-                live.peer.request(method, params, None).await.map_err(|e| IdeError::internal(task.describe(e)))?;
+            let reply: Value = match live.peer.request(method, params, None).await {
+                Ok(reply) => reply,
+                Err(e) => {
+                    {
+                        let mut s = task.state.lock();
+                        s.wanted.retain(|c| c.id != option);
+                        if let Some(prev) = previous.clone() {
+                            s.wanted.push(AgentConfigChoice { id: option.to_owned(), value: prev });
+                        }
+                        if let Some(o) = s.task.config.iter_mut().find(|o| o.id == option) {
+                            o.current = previous.clone();
+                        }
+                        s.task.model = model_of(&s.task.config).or(s.task.model.take());
+                    }
+                    task.persist();
+                    task.emit_task();
+                    return Err(IdeError::internal(task.describe(e)));
+                }
+            };
             if let Some(options) = reply.get("configOptions") {
                 config::merge_update(&mut task.state.lock().task.config, options);
                 model_options = true;
@@ -906,8 +986,6 @@ impl AgentManager {
             if !model_options {
                 s.task.config.retain(|o| o.category.as_deref() != Some("thought_level"));
             }
-            s.wanted.retain(|c| c.id != option);
-            s.wanted.push(AgentConfigChoice { id: option.to_owned(), value: value.clone() });
             if let Some(o) = s.task.config.iter_mut().find(|o| o.id == option) {
                 o.current = Some(value);
             }
@@ -1260,15 +1338,19 @@ impl AgentManager {
     /// Files the task changed since it started.
     pub async fn changes(&self, id: &str) -> IdeResult<Vec<AgentChange>> {
         let task = self.task(id)?;
-        let (cwd, base) = task.cwd_and_base();
+        let at = task.base();
         let before = task.state.lock().before.clone();
-        blocking(move || Ok(worktree::without_untouched(worktree::changes(&cwd, &base)?, &before))).await
+        blocking(move || at.changes(&before)).await
     }
 
     /// Content of `path` (in the task's directory) when the task started.
     pub async fn base_text(&self, id: &str, path: PathBuf) -> IdeResult<Option<String>> {
-        let (cwd, base) = self.task(id)?.cwd_and_base();
-        blocking(move || worktree::file_at(&cwd, &path, &base)).await
+        let at = self.task(id)?.base();
+        blocking(move || match at.rev()? {
+            Some(rev) => worktree::file_at(at.cwd(), &path, &rev),
+            None => Ok(None),
+        })
+        .await
     }
 
     /// Rollback: puts the task's changed files among `rel_paths` (all with `None`) back as they
@@ -1278,16 +1360,17 @@ impl AgentManager {
         if task.state.lock().busy {
             return Err(IdeError::invalid("the agent is working: stop it before rolling back its changes"));
         }
-        let (cwd, base) = task.cwd_and_base();
+        let at = task.base();
         let (before, saved) = {
             let s = task.state.lock();
             (s.before.clone(), s.saved.as_ref().map(|name| self.shared.paths.store_dir.join(name)))
         };
         let restamped = blocking(move || {
-            let changes = worktree::without_untouched(worktree::changes(&cwd, &base)?, &before);
+            let changes = at.changes(&before)?;
+            let rev = at.rev()?;
             let mut restamped = Vec::new();
             for change in changes.iter().filter(|c| rel_paths.as_ref().is_none_or(|p| p.contains(&c.rel_path))) {
-                worktree::restore(&cwd, &base, change, &before, saved.as_deref())?;
+                worktree::restore(at.cwd(), rev.as_deref(), change, &before, saved.as_deref())?;
                 // Back to the user's own edits: not a change of the task any more.
                 if before.contains_key(&change.rel_path) {
                     restamped.push((change.rel_path.clone(), worktree::stamp(&change.path.0)));
@@ -1306,6 +1389,41 @@ impl AgentManager {
         Ok(())
     }
 
+    /// Accept: copies the task's changed files among `rel_paths` (all with `None`) from its
+    /// worktree into the local checkout, uncommitted, for the user to review and commit.
+    /// Files the checkout changed itself are left alone and reported. Only worktree tasks
+    /// have anything to accept.
+    pub async fn accept_changes(&self, id: &str, rel_paths: Option<Vec<String>>) -> IdeResult<AgentAcceptOutcome> {
+        let task = self.task(id)?;
+        if task.state.lock().busy {
+            return Err(IdeError::invalid("the agent is working: stop it before accepting its changes"));
+        }
+        let (isolation, cwd, base, root, before) = {
+            let s = task.state.lock();
+            (
+                s.task.isolation,
+                s.task.cwd.0.clone(),
+                s.task.base_commit.clone(),
+                s.task.project_root.clone().map(|p| p.0).unwrap_or_else(|| self.shared.paths.project_root.clone()),
+                (*s.before).clone(),
+            )
+        };
+        if isolation != Isolation::Worktree {
+            return Err(IdeError::invalid("the task works in the local checkout: there is nothing to accept"));
+        }
+        let Some(base) = base else {
+            return Err(IdeError::invalid("the task has no base revision to accept from"));
+        };
+        blocking(move || {
+            let wanted: Vec<AgentChange> = worktree::without_untouched(worktree::changes(&cwd, &base)?, &before)
+                .into_iter()
+                .filter(|c| rel_paths.as_ref().is_none_or(|p| p.contains(&c.rel_path)))
+                .collect();
+            worktree::accept(&root, &cwd, &base, &wanted)
+        })
+        .await
+    }
+
     /// Stops every agent (project closed).
     pub fn shutdown(&self) {
         for task in self.tasks.read().values() {
@@ -1356,15 +1474,15 @@ impl Task {
         })
     }
 
-    fn cwd_and_base(&self) -> (PathBuf, String) {
+    fn base(&self) -> worktree::TaskBase {
         let s = self.state.lock();
-        // In the project's own checkout the user commits too: compare against the current HEAD,
-        // as the Commit tool window does, so commits made since the task started drop out.
-        let base = match s.task.isolation {
-            Isolation::Local => None,
-            Isolation::Worktree => s.task.base_commit.clone(),
-        };
-        (s.task.cwd.0.clone(), base.unwrap_or_else(|| "HEAD".into()))
+        let cwd = s.task.cwd.0.clone();
+        match s.task.isolation {
+            Isolation::Local => worktree::TaskBase::Local { cwd, start: s.task.base_commit.clone() },
+            Isolation::Worktree => {
+                worktree::TaskBase::Worktree { cwd, base: s.task.base_commit.clone().unwrap_or_else(|| "HEAD".into()) }
+            }
+        }
     }
 
     fn emit_task(&self) {
@@ -2124,6 +2242,44 @@ impl Task {
             .iter()
             .map(|question| question.answer_key.clone().unwrap_or_else(|| question.question.clone()))
             .collect();
+        if let Some(hook) = self.shared.security.read().clone()
+            && let Some(command) = security::extract_command(params)
+        {
+            match security::evaluate_command(&command, &hook()) {
+                security::PolicyDecision::Blocked(pattern) => {
+                    let reject = options.iter().find(|o| o.kind.starts_with("reject")).cloned();
+                    let _ = self.push_entry(AgentEntry::Permission {
+                        id,
+                        title,
+                        options,
+                        questions: Vec::new(),
+                        chosen: Some(format!("Blocked by policy ({pattern})")),
+                    });
+                    return match reject {
+                        Some(option) => json!({ "outcome": { "outcome": "selected", "optionId": option.id } }),
+                        None => json!({ "outcome": { "outcome": "cancelled" } }),
+                    };
+                }
+                security::PolicyDecision::Allowed => {
+                    if let Some(allow) = options
+                        .iter()
+                        .find(|o| o.kind == "allow_once")
+                        .or_else(|| options.iter().find(|o| o.kind.starts_with("allow")))
+                        .cloned()
+                    {
+                        let _ = self.push_entry(AgentEntry::Permission {
+                            id,
+                            title,
+                            options,
+                            questions: Vec::new(),
+                            chosen: Some(format!("{} (whitelisted)", allow.name)),
+                        });
+                        return json!({ "outcome": { "outcome": "selected", "optionId": allow.id } });
+                    }
+                }
+                security::PolicyDecision::AskUser => {}
+            }
+        }
         let (tx, rx) = std::sync::mpsc::channel();
         let entry =
             self.push_entry(AgentEntry::Permission { id, title, options: options.clone(), questions, chosen: None });
@@ -2437,7 +2593,7 @@ fn with_details(message: String, data: Option<&Value>) -> String {
     }
 }
 
-fn client_info() -> Value {
+pub(crate) fn client_info() -> Value {
     json!({ "name": "OpenIDEA", "version": env!("CARGO_PKG_VERSION") })
 }
 
@@ -2496,6 +2652,16 @@ fn retry_of(update: &Value, now: f64) -> Option<AgentRetry> {
     })
 }
 
+fn apply_config_choice(task: &Task, option: &str, value: &str) {
+    let mut s = task.state.lock();
+    s.wanted.retain(|c| c.id != option);
+    s.wanted.push(AgentConfigChoice { id: option.to_owned(), value: value.to_owned() });
+    if let Some(o) = s.task.config.iter_mut().find(|o| o.id == option) {
+        o.current = Some(value.to_owned());
+    }
+    s.task.model = model_of(&s.task.config).or(s.task.model.take());
+}
+
 fn model_of(config: &[AgentConfigOption]) -> Option<String> {
     config.iter().find(|o| o.category.as_deref() == Some("model")).and_then(|o| o.current.clone())
 }

crates/ide-agent/src/model.rs

@@ -602,3 +602,49 @@ pub struct McpServerInput {
 fn default_true() -> bool {
     true
 }
+
+/// Payload for creating a custom ACP agent (always the ACP driver); the id
+/// becomes the `<config>/agents/<id>.toml` file name.
+#[derive(Clone, Debug, Deserialize, Type)]
+#[serde(rename_all = "camelCase", deny_unknown_fields)]
+pub struct CustomAgentInput {
+    pub id: String,
+    pub name: String,
+    pub command: String,
+    #[serde(default)]
+    pub args: Vec<String>,
+    #[serde(default)]
+    pub env: BTreeMap<String, String>,
+}
+
+/// What importing one entry of a JetBrains `acp.json` file did.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct AcpImportOutcome {
+    /// The `agent_servers` key the entry was imported from.
+    pub name: String,
+    /// The id its agent file would get (also when skipped).
+    pub id: String,
+    pub saved: bool,
+    /// Why the entry was skipped; empty when it was saved.
+    #[serde(default)]
+    pub reason: String,
+}
+
+/// What accepting a worktree task's changes copied into the local checkout.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct AgentAcceptOutcome {
+    /// Relative paths copied into the checkout (uncommitted), including ones already identical.
+    pub accepted: Vec<String>,
+    /// Files left alone because the checkout has its own edits to them.
+    pub skipped: Vec<AgentAcceptSkipped>,
+}
+
+/// A file accept left alone, with why.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct AgentAcceptSkipped {
+    pub path: String,
+    pub reason: String,
+}

crates/ide-agent/src/provider.rs

@@ -2,7 +2,7 @@
 //! `<config>/agents/<id>.toml` (written by hand, or by installing one from the ACP
 //! Registry, see `registry`).
 
-use crate::{AgentCommandReadOnlyReason, AgentProvider, AgentSource};
+use crate::{AcpImportOutcome, AgentCommandReadOnlyReason, AgentProvider, AgentSource, CustomAgentInput};
 use ide_core::{IdeError, IdeResult};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
@@ -278,6 +278,127 @@ fn update_builtin(custom_dir: &Path, id: &str, change: impl FnOnce(&mut CustomAg
     Ok(())
 }
 
+/// Saves a new custom agent; refuses built-in and ACP Registry ids, taken ids
+/// and an empty command. The id is also the agent file's name, so it must be
+/// a safe file stem.
+pub(crate) fn save_custom(custom_dir: &Path, input: &CustomAgentInput) -> IdeResult<()> {
+    let id = validated_custom_id(&input.id)?;
+    if builtin_spec(&id).is_some() {
+        return Err(IdeError::invalid(format!("{id} is a built-in agent; change its command instead")));
+    }
+    if input.command.trim().is_empty() {
+        return Err(IdeError::invalid("the agent command must not be empty"));
+    }
+    let file = custom_dir.join(format!("{id}.toml"));
+    if file.try_exists()? {
+        if CustomAgent::read(&file).is_ok_and(|a| a.registry.is_some()) {
+            return Err(IdeError::invalid(format!(
+                "{id} is installed from the ACP Registry; uninstall it there to replace it"
+            )));
+        }
+        return Err(IdeError::invalid(format!("there is already a custom agent '{id}'")));
+    }
+    CustomAgent {
+        name: Some(input.name.clone()),
+        driver: Driver::Acp,
+        command: input.command.clone(),
+        args: input.args.clone(),
+        env: input.env.clone(),
+        registry: None,
+    }
+    .write(&file)?;
+    Ok(())
+}
+
+/// Removes a custom agent's file; refuses built-in, ACP Registry and missing ids.
+pub(crate) fn remove_custom(custom_dir: &Path, id: &str) -> IdeResult<()> {
+    let id = validated_custom_id(id)?;
+    let id = id.as_str();
+    if builtin_spec(id).is_some() {
+        return Err(IdeError::invalid(format!("{id} is a built-in agent and cannot be removed")));
+    }
+    let file = custom_dir.join(format!("{id}.toml"));
+    let agent =
+        CustomAgent::read(&file).map_err(|_| IdeError::not_found(format!("there is no custom agent '{id}'")))?;
+    if agent.registry.is_some() {
+        return Err(IdeError::invalid(format!("{id} is installed from the ACP Registry; uninstall it there")));
+    }
+    match std::fs::remove_file(&file) {
+        Err(e) if e.kind() != std::io::ErrorKind::NotFound => Err(e.into()),
+        _ => Ok(()),
+    }
+}
+
+/// Imports a JetBrains `acp.json` file's `agent_servers` entries as custom
+/// agents, one outcome per entry; entries that collide, lack a command or
+/// have no usable name are skipped with a reason.
+pub(crate) fn import_acp(custom_dir: &Path, text: &str) -> IdeResult<Vec<AcpImportOutcome>> {
+    #[derive(Deserialize)]
+    struct AcpJson {
+        #[serde(default)]
+        agent_servers: BTreeMap<String, AcpServer>,
+    }
+    #[derive(Deserialize)]
+    struct AcpServer {
+        #[serde(default)]
+        command: String,
+        #[serde(default)]
+        args: Vec<String>,
+        #[serde(default)]
+        env: BTreeMap<String, String>,
+    }
+    let parsed: AcpJson =
+        serde_json::from_str(text).map_err(|e| IdeError::invalid(format!("not an acp.json file: {e}")))?;
+    let mut outcomes = Vec::with_capacity(parsed.agent_servers.len());
+    for (name, server) in parsed.agent_servers {
+        let id = slugify_id(&name);
+        let mut outcome = AcpImportOutcome { name, id: id.clone(), saved: false, reason: String::new() };
+        if id.is_empty() {
+            outcome.reason = "the name has no usable characters for an id".to_owned();
+        } else if builtin_spec(&id).is_some() {
+            outcome.reason = format!("{id} is a built-in agent");
+        } else if server.command.trim().is_empty() {
+            outcome.reason = "the entry has no command".to_owned();
+        } else if custom_dir.join(format!("{id}.toml")).try_exists()? {
+            outcome.reason = format!("there is already a custom agent '{id}'");
+        } else {
+            CustomAgent {
+                name: Some(outcome.name.clone()),
+                driver: Driver::Acp,
+                command: server.command,
+                args: server.args,
+                env: server.env,
+                registry: None,
+            }
+            .write(&custom_dir.join(format!("{id}.toml")))?;
+            outcome.saved = true;
+        }
+        outcomes.push(outcome);
+    }
+    Ok(outcomes)
+}
+
+/// A custom agent id doubles as a file stem: letters, digits, `-` and `_` only.
+fn validated_custom_id(id: &str) -> IdeResult<String> {
+    if !id.is_empty() && id.chars().all(|c| c.is_ascii_alphanumeric() || c == '-' || c == '_') {
+        return Ok(id.to_owned());
+    }
+    Err(IdeError::invalid(format!("'{id}' is not a usable agent id (letters, digits, '-' and '_' only)")))
+}
+
+/// Turns an `acp.json` server name into a file-stem id (`"My Agent!"` → `"my-agent"`).
+fn slugify_id(name: &str) -> String {
+    let mut id = String::with_capacity(name.len());
+    for c in name.chars() {
+        if c.is_ascii_alphanumeric() {
+            id.push(c.to_ascii_lowercase());
+        } else if !id.ends_with('-') {
+            id.push('-');
+        }
+    }
+    id.trim_matches('-').to_owned()
+}
+
 /// An agent file, `<config>/agents/<id>.toml`.
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
@@ -753,4 +874,80 @@ mod tests {
         assert_eq!(spec.source, AgentSource::Registry { version: "0.10.0".into(), update: None });
         assert!(toml::from_str::<CustomAgent>("command = \"x\"\n[registry]\nid = \"x\"\n").is_err());
     }
+
+    fn custom_input(id: &str) -> CustomAgentInput {
+        CustomAgentInput {
+            id: id.into(),
+            name: "Mine".into(),
+            command: "/opt/mine".into(),
+            args: vec!["acp".into()],
+            env: BTreeMap::from([("K".to_owned(), "v".to_owned())]),
+        }
+    }
+
+    #[test]
+    fn custom_agents_save_list_and_remove() {
+        let dir = tempfile::tempdir().unwrap();
+        save_custom(dir.path(), &custom_input("mine")).unwrap();
+        let mine = load(Some(dir.path())).into_iter().find(|s| s.id == "mine").unwrap();
+        assert_eq!((mine.name.as_str(), mine.command.as_str()), ("Mine", "/opt/mine"));
+        assert_eq!(mine.env, vec![("K".to_owned(), "v".to_owned())]);
+        assert_eq!(mine.source, AgentSource::Custom);
+        remove_custom(dir.path(), "mine").unwrap();
+        assert!(!load(Some(dir.path())).iter().any(|s| s.id == "mine"));
+        remove_custom(dir.path(), "mine").unwrap_err();
+    }
+
+    #[test]
+    fn custom_agents_refuse_builtin_registry_and_bad_ids() {
+        let dir = tempfile::tempdir().unwrap();
+        save_custom(dir.path(), &custom_input("claude")).unwrap_err();
+        save_custom(dir.path(), &custom_input("../evil")).unwrap_err();
+        save_custom(dir.path(), &custom_input("")).unwrap_err();
+        let mut empty_command = custom_input("mine");
+        empty_command.command = "  ".into();
+        save_custom(dir.path(), &empty_command).unwrap_err();
+        save_custom(dir.path(), &custom_input("mine")).unwrap();
+        save_custom(dir.path(), &custom_input("mine")).unwrap_err();
+        remove_custom(dir.path(), "claude").unwrap_err();
+        // An id that isn't a plain file stem never reaches outside the agents directory.
+        let outside = dir.path().join("outside.toml");
+        std::fs::write(&outside, "command = \"/bin/sh\"\n").unwrap();
+        let agents = dir.path().join("agents");
+        std::fs::create_dir(&agents).unwrap();
+        remove_custom(&agents, "../outside").unwrap_err();
+        assert!(outside.exists());
+        std::fs::write(
+            dir.path().join("amp-acp.toml"),
+            "command = \"/registry/amp\"\n[registry]\nid = \"amp-acp\"\nversion = \"1.0\"\n",
+        )
+        .unwrap();
+        save_custom(dir.path(), &custom_input("amp-acp")).unwrap_err();
+        remove_custom(dir.path(), "amp-acp").unwrap_err();
+    }
+
+    #[test]
+    fn acp_json_imports_servers_and_skips_collisions() {
+        let dir = tempfile::tempdir().unwrap();
+        save_custom(dir.path(), &custom_input("taken")).unwrap();
+        let outcomes = import_acp(
+            dir.path(),
+            r#"{"agent_servers": {
+                "My Agent!": {"command": "/opt/agent", "args": ["--acp"], "env": {"K": "v"}},
+                "taken": {"command": "/opt/taken"},
+                "claude": {"command": "/opt/claude"},
+                "!!!": {"command": "/opt/noname"},
+                "silent": {"args": []}
+            }}"#,
+        )
+        .unwrap();
+        let saved: Vec<&str> = outcomes.iter().filter(|o| o.saved).map(|o| o.id.as_str()).collect();
+        assert_eq!(saved, ["my-agent"]);
+        assert!(outcomes.iter().filter(|o| !o.saved).all(|o| !o.reason.is_empty()));
+        let mine = load(Some(dir.path())).into_iter().find(|s| s.id == "my-agent").unwrap();
+        assert_eq!((mine.name.as_str(), mine.command.as_str()), ("My Agent!", "/opt/agent"));
+        assert_eq!(mine.source, AgentSource::Custom);
+        import_acp(dir.path(), "not json").unwrap_err();
+        assert!(import_acp(dir.path(), "{}").unwrap().is_empty());
+    }
 }

crates/ide-agent/src/security.rs

@@ -0,0 +1,487 @@
+//! Command execution security policy (Whitelist / Blacklist) for coding agents.
+
+use ide_core::settings::AgentSecuritySettings;
+use serde_json::Value;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum PolicyDecision {
+    /// Command matched a blacklist pattern (`pattern`).
+    Blocked(String),
+    /// Command matched the whitelist and no blacklist pattern.
+    Allowed,
+    /// Neither matched; prompt the user as usual.
+    AskUser,
+}
+
+/// Extracts the shell command string from an ACP `session/request_permission` payload
+/// when the request is for executing a command.
+pub fn extract_command(params: &Value) -> Option<String> {
+    let tool = params.get("toolCall").or_else(|| params.pointer("/subject/toolCall"))?;
+    let raw_cmd = tool.pointer("/rawInput/command").or_else(|| tool.pointer("/rawInput/cmd"));
+    if let Some(cmd) = raw_cmd.and_then(command_from_value) {
+        return Some(cmd);
+    }
+    let kind = tool.get("kind").and_then(Value::as_str).unwrap_or_default();
+    let name = tool.get("name").and_then(Value::as_str).unwrap_or_default();
+    let title =
+        tool.get("title").and_then(Value::as_str).or_else(|| params.get("title").and_then(Value::as_str))?.trim();
+    if let Some(cmd) = title.strip_prefix("Run ").map(str::trim).filter(|s| !s.is_empty()) {
+        return Some(cmd.to_owned());
+    }
+    if (kind == "execute" || matches!(name, "Bash" | "PowerShell" | "Execute" | "Run" | "terminal"))
+        && !title.is_empty()
+        && title != "Terminal"
+        && title != "Run a command"
+    {
+        return Some(title.to_owned());
+    }
+    None
+}
+
+fn command_from_value(val: &Value) -> Option<String> {
+    match val {
+        Value::String(s) => {
+            let trimmed = s.trim();
+            (!trimmed.is_empty()).then(|| trimmed.to_owned())
+        }
+        Value::Array(items) => {
+            let words: Vec<&str> = items.iter().filter_map(Value::as_str).collect();
+            if words.is_empty() {
+                return None;
+            }
+            let cmd = match words.as_slice() {
+                [_, flag, script] if flag.starts_with('-') && flag.ends_with('c') => (*script).trim().to_owned(),
+                _ => words.join(" ").trim().to_owned(),
+            };
+            (!cmd.is_empty()).then_some(cmd)
+        }
+        _ => None,
+    }
+}
+
+/// Checks whether a single pattern matches `command` using prefix + glob rules:
+/// - If `pattern` contains `*` or `?`, matches using glob wildcards (where `*` matches
+///   any sequence of characters). A trailing ` *` in the pattern also matches the bare
+///   command without arguments (e.g. `git status *` matches `git status`).
+/// - Otherwise, matches when `command` equals `pattern` or starts with `pattern` followed
+///   by whitespace (prefix match at word boundary).
+pub fn matches_command(pattern: &str, command: &str) -> bool {
+    let pat = pattern.trim();
+    let cmd = command.trim();
+    if pat.is_empty() || cmd.is_empty() {
+        return false;
+    }
+    if pat.contains('*') || pat.contains('?') {
+        if let Some(stem) = pat.strip_suffix(" *")
+            && cmd == stem.trim()
+        {
+            return true;
+        }
+        wildcard_match(pat.as_bytes(), cmd.as_bytes())
+    } else {
+        cmd == pat || cmd.strip_prefix(pat).is_some_and(|rest| rest.starts_with(char::is_whitespace))
+    }
+}
+
+fn wildcard_match(pat: &[u8], text: &[u8]) -> bool {
+    let (mut p, mut t) = (0, 0);
+    let (mut star_p, mut star_t) = (None, 0);
+    while t < text.len() {
+        if p < pat.len() && (pat[p] == b'?' || pat[p] == text[t]) {
+            p += 1;
+            t += 1;
+        } else if p < pat.len() && pat[p] == b'*' {
+            star_p = Some(p);
+            p += 1;
+            star_t = t;
+        } else if let Some(sp) = star_p {
+            p = sp + 1;
+            star_t += 1;
+            t = star_t;
+        } else {
+            return false;
+        }
+    }
+    while p < pat.len() && pat[p] == b'*' {
+        p += 1;
+    }
+    p == pat.len()
+}
+
+/// Matches an allowed command entry against a sub-command.
+/// An allow entry is a whole command or a prefix only up to a word boundary:
+/// e.g. `git status` matches `git status` and `git status -s`, but NOT `git statusx`.
+/// Any accidental trailing `*` in the allow entry is stripped so `git status*` behaves
+/// cleanly as a prefix at word boundaries instead of a glob wildcard.
+pub fn matches_allow_entry(entry: &str, command: &str) -> bool {
+    let mut entry = entry.trim();
+    if let Some(stripped) = entry.strip_suffix('*') {
+        entry = stripped.trim_end();
+    }
+    let cmd = command.trim();
+    if entry.is_empty() || cmd.is_empty() {
+        return false;
+    }
+    cmd == entry || cmd.strip_prefix(entry).is_some_and(|rest| rest.starts_with(char::is_whitespace))
+}
+
+/// Checks whether a word is an environment variable assignment (`IDENTIFIER=...`).
+fn is_env_assignment_word(word: &str) -> bool {
+    let Some((name, _)) = word.split_once('=') else {
+        return false;
+    };
+    if name.is_empty() {
+        return false;
+    }
+    let mut chars = name.chars();
+    match chars.next() {
+        Some(c) if c.is_ascii_alphabetic() || c == '_' => {}
+        _ => return false,
+    }
+    chars.all(|c| c.is_ascii_alphanumeric() || c == '_')
+}
+
+/// Returns true if the sub-command starts with an environment variable assignment,
+/// e.g. `FOO=bar cmd` or `PORT=3000`.
+fn has_leading_env_assignment(cmd: &str) -> bool {
+    let trimmed = cmd.trim_start();
+    let bytes = trimmed.as_bytes();
+    let mut i = 0;
+    let mut quote: Option<u8> = None;
+    while i < bytes.len() {
+        let b = bytes[i];
+        if b == b'\\' && quote != Some(b'\'') && i + 1 < bytes.len() {
+            i += 2;
+            continue;
+        }
+        if let Some(q) = quote {
+            if b == q {
+                quote = None;
+            }
+            i += 1;
+            continue;
+        }
+        if b == b'\'' || b == b'"' {
+            quote = Some(b);
+            i += 1;
+            continue;
+        }
+        if b.is_ascii_whitespace() {
+            break;
+        }
+        i += 1;
+    }
+    let first_word = &trimmed[..i];
+    is_env_assignment_word(first_word)
+}
+
+/// Checks whether `command` contains shell constructs that must never be auto-approved:
+/// - Command substitution: `$(...)` or backticks
+/// - Redirection: `>`, `>>`, `<`
+/// - Here-docs: `<<`
+/// - Subshells: `(...)`
+/// - Leading environment assignments: `VAR=val cmd`
+pub fn has_unsafe_shell_syntax(command: &str) -> bool {
+    let cmd = command.trim();
+    if cmd.is_empty() {
+        return false;
+    }
+
+    if has_leading_env_assignment(cmd) {
+        return true;
+    }
+
+    let bytes = cmd.as_bytes();
+    let mut i = 0;
+    let mut quote: Option<u8> = None;
+
+    while i < bytes.len() {
+        let b = bytes[i];
+
+        if b == b'\\' && quote != Some(b'\'') && i + 1 < bytes.len() {
+            i += 2;
+            continue;
+        }
+
+        if let Some(q) = quote {
+            if b == q {
+                quote = None;
+                i += 1;
+                continue;
+            }
+            // Inside double quotes: $(...) and `...` are evaluated by the shell.
+            if q == b'"' {
+                if b == b'`' {
+                    return true;
+                }
+                if b == b'$' && i + 1 < bytes.len() && bytes[i + 1] == b'(' {
+                    return true;
+                }
+            }
+            i += 1;
+            continue;
+        }
+
+        match b {
+            b'\'' | b'"' => {
+                quote = Some(b);
+                i += 1;
+            }
+            b'`' => return true,
+            b'$' if i + 1 < bytes.len() && bytes[i + 1] == b'(' => return true,
+            b'<' | b'>' => return true,
+            b'(' | b')' => return true,
+            _ => i += 1,
+        }
+    }
+
+    false
+}
+
+/// Splits a shell command into sub-commands separated by `;`, `&&`, `||`, `|`, or `\n`
+/// (outside single/double quotes) so compound commands cannot bypass policy checks.
+fn split_subcommands(command: &str) -> Vec<&str> {
+    let bytes = command.as_bytes();
+    let mut out = Vec::new();
+    let mut start = 0;
+    let mut i = 0;
+    let mut quote: Option<u8> = None;
+
+    while i < bytes.len() {
+        let b = bytes[i];
+        if let Some(q) = quote {
+            if b == b'\\' && q == b'"' && i + 1 < bytes.len() {
+                i += 2;
+                continue;
+            }
+            if b == q {
+                quote = None;
+            }
+            i += 1;
+            continue;
+        }
+        match b {
+            b'\'' | b'"' => {
+                quote = Some(b);
+                i += 1;
+            }
+            b'\\' if i + 1 < bytes.len() => {
+                i += 2;
+            }
+            b';' | b'\n' => {
+                let seg = command[start..i].trim();
+                if !seg.is_empty() {
+                    out.push(seg);
+                }
+                i += 1;
+                start = i;
+            }
+            b'&' | b'|' => {
+                let seg = command[start..i].trim();
+                if !seg.is_empty() {
+                    out.push(seg);
+                }
+                if i + 1 < bytes.len() && bytes[i + 1] == b {
+                    i += 2;
+                } else {
+                    i += 1;
+                }
+                start = i;
+            }
+            _ => i += 1,
+        }
+    }
+    let tail = command[start..].trim();
+    if !tail.is_empty() {
+        out.push(tail);
+    }
+    out
+}
+
+/// Evaluates `command` against `settings`:
+/// 1. Blacklist takes precedence: if the full command or any sub-command matches a
+///    `blocked_commands` entry, returns [`PolicyDecision::Blocked`].
+/// 2. Whitelist: allowed_commands cannot auto-approve when empty.
+/// 3. Every sub-command in a chain must be safe (no command substitution, redirection,
+///    subshell, or env assignments) and match at least one `allowed_commands` entry
+///    exactly or up to word boundary; otherwise falls back to [`PolicyDecision::AskUser`].
+pub fn evaluate_command(command: &str, settings: &AgentSecuritySettings) -> PolicyDecision {
+    let cmd = command.trim();
+    if cmd.is_empty() {
+        return PolicyDecision::AskUser;
+    }
+    let subcommands = split_subcommands(cmd);
+
+    for pat in &settings.blocked_commands {
+        let pat = pat.trim();
+        if pat.is_empty() {
+            continue;
+        }
+        if matches_command(pat, cmd) || subcommands.iter().any(|sub| matches_command(pat, sub)) {
+            return PolicyDecision::Blocked(pat.to_owned());
+        }
+    }
+
+    if settings.allowed_commands.is_empty() || subcommands.is_empty() {
+        return PolicyDecision::AskUser;
+    }
+
+    let all_allowed = subcommands.iter().all(|sub| {
+        let s = sub.trim();
+        if s.is_empty() || has_unsafe_shell_syntax(s) {
+            return false;
+        }
+        settings.allowed_commands.iter().any(|entry| matches_allow_entry(entry, s))
+    });
+
+    if all_allowed {
+        return PolicyDecision::Allowed;
+    }
+
+    PolicyDecision::AskUser
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn prefix_and_glob_matching() {
+        assert!(matches_command("git status", "git status"));
+        assert!(matches_command("git status", "git status -s"));
+        assert!(!matches_command("git status", "git statusbar"));
+        assert!(matches_command("git status*", "git status"));
+        assert!(matches_command("git status*", "git status --short"));
+        assert!(matches_command("npm test *", "npm test"));
+        assert!(matches_command("npm test *", "npm test unit"));
+        assert!(matches_command("rm -rf *", "rm -rf /tmp/foo"));
+        assert!(matches_command("rm -rf *", "rm -rf /"));
+    }
+
+    #[test]
+    fn blacklist_takes_precedence_and_catches_chained_commands() {
+        let settings = AgentSecuritySettings::default();
+        assert_eq!(evaluate_command("rm -rf /tmp/build", &settings), PolicyDecision::Blocked("rm -rf *".into()));
+        assert_eq!(evaluate_command("git status && rm -rf /", &settings), PolicyDecision::Blocked("rm -rf *".into()));
+        assert_eq!(evaluate_command(":(){ :|:& };:", &settings), PolicyDecision::Blocked(":(){ :|:& };:".into()));
+    }
+
+    #[test]
+    fn allow_entry_matching_word_boundary() {
+        assert!(matches_allow_entry("git status", "git status"));
+        assert!(matches_allow_entry("git status", "git status -s"));
+        assert!(!matches_allow_entry("git status", "git statusbar"));
+        assert!(!matches_allow_entry("git status", "git statusx"));
+        // Trailing asterisk in allow entry normalizes cleanly to word boundary prefix
+        assert!(matches_allow_entry("git status*", "git status"));
+        assert!(matches_allow_entry("git status*", "git status --short"));
+        assert!(!matches_allow_entry("git status*", "git statusbar"));
+        assert!(matches_allow_entry("ls", "ls"));
+        assert!(matches_allow_entry("ls", "ls -la"));
+        assert!(!matches_allow_entry("ls", "lsof"));
+        assert!(matches_allow_entry("cargo check", "cargo check"));
+        assert!(matches_allow_entry("cargo check", "cargo check --workspace"));
+        assert!(!matches_allow_entry("cargo check", "cargo checkmate"));
+    }
+
+    #[test]
+    fn unsafe_shell_syntax_detection() {
+        // Command substitutions: $(...) and `...`
+        assert!(has_unsafe_shell_syntax("echo $(whoami)"));
+        assert!(has_unsafe_shell_syntax("echo \"user: $(whoami)\""));
+        assert!(has_unsafe_shell_syntax("echo `whoami`"));
+        assert!(has_unsafe_shell_syntax("echo \"`whoami`\""));
+
+        // Redirections: >, >>, <
+        assert!(has_unsafe_shell_syntax("git status > /tmp/out"));
+        assert!(has_unsafe_shell_syntax("git status >> /tmp/out"));
+        assert!(has_unsafe_shell_syntax("cat < /tmp/in"));
+        assert!(has_unsafe_shell_syntax("cat << 'EOF'"));
+
+        // Subshells: (...)
+        assert!(has_unsafe_shell_syntax("(cd /tmp && ls)"));
+        assert!(has_unsafe_shell_syntax("git status && (exit 1)"));
+
+        // Environment assignments: VAR=val ...
+        assert!(has_unsafe_shell_syntax("FOO=bar git status"));
+        assert!(has_unsafe_shell_syntax("PORT=3000 npm test"));
+        assert!(has_unsafe_shell_syntax("_SECRET=123 cargo test"));
+        assert!(has_unsafe_shell_syntax("A=\"b c\" git status"));
+
+        // Safe constructs with characters inside quotes or command flags
+        assert!(!has_unsafe_shell_syntax("git commit -m \"fix <bug> and (issue)\""));
+        assert!(!has_unsafe_shell_syntax("git commit -m 'fix <bug>'"));
+        assert!(!has_unsafe_shell_syntax("cargo test --test=unit"));
+        assert!(!has_unsafe_shell_syntax("git status -s"));
+    }
+
+    #[test]
+    fn default_settings_has_no_auto_approval_and_blocks_dangerous_defaults() {
+        let settings = AgentSecuritySettings::default();
+        assert!(settings.allowed_commands.is_empty(), "allowed_commands must start empty");
+        // Safe commands ask user by default
+        assert_eq!(evaluate_command("git status", &settings), PolicyDecision::AskUser);
+        assert_eq!(evaluate_command("ls", &settings), PolicyDecision::AskUser);
+        assert_eq!(evaluate_command("cargo check", &settings), PolicyDecision::AskUser);
+        // Blacklist patterns are still blocked by default
+        assert_eq!(evaluate_command("rm -rf /", &settings), PolicyDecision::Blocked("rm -rf *".into()));
+        assert_eq!(evaluate_command("rm -rf /tmp/test", &settings), PolicyDecision::Blocked("rm -rf *".into()));
+    }
+
+    #[test]
+    fn whitelist_allows_safe_single_and_chained_commands_only() {
+        let settings = AgentSecuritySettings {
+            allowed_commands: vec!["git status".into(), "git diff".into(), "cargo test".into()],
+            blocked_commands: vec!["rm -rf *".into()],
+        };
+        assert_eq!(evaluate_command("git status -s", &settings), PolicyDecision::Allowed);
+        assert_eq!(evaluate_command("git diff HEAD~1", &settings), PolicyDecision::Allowed);
+        assert_eq!(evaluate_command("git status && cargo test", &settings), PolicyDecision::Allowed);
+
+        // Word boundary: git statusx must not match git status
+        assert_eq!(evaluate_command("git statusx", &settings), PolicyDecision::AskUser);
+
+        // Unsafe syntax (redirection, command substitution, env assignment) falls back to AskUser
+        assert_eq!(evaluate_command("git status > out.txt", &settings), PolicyDecision::AskUser);
+        assert_eq!(evaluate_command("git status $(whoami)", &settings), PolicyDecision::AskUser);
+        assert_eq!(evaluate_command("FOO=bar git status", &settings), PolicyDecision::AskUser);
+
+        // Chaining an unapproved command must still ask the user.
+        assert_eq!(evaluate_command("git status && curl https://example.com", &settings), PolicyDecision::AskUser);
+        assert_eq!(evaluate_command("cargo publish", &settings), PolicyDecision::AskUser);
+
+        // Blacklist still takes precedence over whitelist
+        assert_eq!(evaluate_command("git status && rm -rf /", &settings), PolicyDecision::Blocked("rm -rf *".into()));
+    }
+
+    #[test]
+    fn extracts_command_from_v1_v2_and_codex_payloads() {
+        let claude = json!({
+            "toolCall": {
+                "title": "git status",
+                "kind": "execute",
+                "rawInput": { "command": "git status --short" }
+            }
+        });
+        assert_eq!(extract_command(&claude).as_deref(), Some("git status --short"));
+
+        let codex = json!({
+            "toolCall": {
+                "title": "Run cargo test",
+                "kind": "execute",
+                "rawInput": { "command": ["/bin/zsh", "-lc", "cargo test --workspace"] }
+            }
+        });
+        assert_eq!(extract_command(&codex).as_deref(), Some("cargo test --workspace"));
+
+        let write = json!({
+            "toolCall": {
+                "title": "Write foo.txt",
+                "kind": "edit",
+                "rawInput": { "file_path": "foo.txt" }
+            }
+        });
+        assert_eq!(extract_command(&write), None);
+    }
+}

crates/ide-agent/src/tests.rs

@@ -43,6 +43,11 @@ struct FakeAgent {
     /// Hold the late mode reply until the prompt's permission request is already waiting.
     hold_late_mode: bool,
     empty_config: AtomicBool,
+    /// Blocks `session/new` until discovery times out (see `acp::discover` test timeout).
+    hold_session_new: AtomicBool,
+    /// Sleeps this long at the start of `session/set_config_option`, after noting the time.
+    delay_config: Duration,
+    config_entered: Mutex<Option<std::time::Instant>>,
     /// Config options `session/new` reports after the model one (per-model efforts, say).
     extra_options: Mutex<Vec<Value>>,
     model_options: Mutex<HashMap<String, Vec<Value>>>,
@@ -157,6 +162,9 @@ impl Handler for FakeAgent {
                 )
             }
             "session/new" => {
+                if self.hold_session_new.load(Ordering::Acquire) {
+                    std::thread::sleep(Duration::from_secs(5));
+                }
                 if self.empty_config.load(Ordering::Acquire) {
                     return Ok(json!({"sessionId": "s1"}));
                 }
@@ -190,6 +198,10 @@ impl Handler for FakeAgent {
                 }
             }
             "session/set_config_option" | "session/set_mode" => {
+                if method == "session/set_config_option" && !self.delay_config.is_zero() {
+                    *self.config_entered.lock() = Some(std::time::Instant::now());
+                    std::thread::sleep(self.delay_config);
+                }
                 self.calls.lock().push(format!("{method} {}", params.get("value").or(params.get("modeId")).unwrap()));
                 if params["configId"] == "model" && !self.model_options.lock().is_empty() {
                     return Ok(json!({"configOptions": self.options_for(params["value"].as_str().unwrap())}));
@@ -2631,6 +2643,92 @@ async fn session_settings_win_over_discovery_in_memory_and_on_disk() {
     }
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn provider_reload_does_not_start_acp_discovery() {
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tempfile::tempdir().unwrap().path(), agent.clone());
+    mgr.reload_providers();
+    tokio::time::sleep(Duration::from_millis(100)).await;
+    assert!(agent.calls.lock().is_empty(), "reload must not spawn cursor-agent");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn composer_commands_discover_cursor_effort_and_fast() {
+    let agent = Arc::new(FakeAgent {
+        extra_options: Mutex::new(vec![
+            json!({"id": "effort", "type": "select", "currentValue": "medium",
+                "options": [{"value": "low"}, {"value": "medium"}, {"value": "high"}]}),
+            json!({"id": "fast", "type": "select", "currentValue": "false",
+                "options": [{"value": "false", "name": "Off"}, {"value": "true", "name": "On"}]}),
+        ]),
+        ..Default::default()
+    });
+    let mgr = manager(tempfile::tempdir().unwrap().path(), agent.clone());
+    mgr.commands("cursor", None).await.unwrap();
+    let calls = agent.calls.lock();
+    assert!(calls.iter().any(|m| m.as_str() == "session/new"));
+    assert_eq!(calls.iter().filter(|m| m.as_str() == "initialize").count(), 1);
+    let cursor = mgr.providers().into_iter().find(|p| p.id == "cursor").unwrap();
+    assert_eq!(cursor.config.iter().find(|o| o.id == "fast").unwrap().current.as_deref(), Some("false"));
+    assert!(
+        cursor
+            .thought_levels
+            .values()
+            .next()
+            .is_some_and(|levels| { levels.iter().any(|o| o.category.as_deref() == Some("thought_level")) })
+    );
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn config_choice_shows_before_the_agent_answers() {
+    let agent = Arc::new(FakeAgent {
+        extra_options: Mutex::new(vec![json!({
+            "id": "fast", "category": "model_config", "type": "select", "currentValue": "true",
+            "options": [{"value": "true", "name": "On"}, {"value": "false", "name": "Off"}]
+        })]),
+        delay_config: Duration::from_millis(300),
+        ..Default::default()
+    });
+    let mgr = manager(tempfile::tempdir().unwrap().path(), agent.clone());
+    let shown: Arc<Mutex<Option<std::time::Instant>>> = Arc::default();
+    let mark = shown.clone();
+    mgr.subscribe(Arc::new(move |e| {
+        if let AgentEvent::Task { task } = e
+            && task.config.iter().any(|o| o.id == "fast" && o.current.as_deref() == Some("false"))
+            && mark.lock().is_none()
+        {
+            *mark.lock() = Some(std::time::Instant::now());
+        }
+    }));
+    let task = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("again"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    mgr.set_config(&task.id, "fast", "false".into()).await.unwrap();
+    let shown = (*shown.lock()).expect("the switch moved");
+    let entered = (*agent.config_entered.lock()).expect("the agent received the change");
+    assert!(shown < entered, "the composer updates before the agent answers");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn discovery_times_out_when_session_new_hangs() {
+    let agent = Arc::new(FakeAgent { hold_session_new: AtomicBool::new(true), ..Default::default() });
+    let mgr = manager(tempfile::tempdir().unwrap().path(), agent.clone());
+    let started = std::time::Instant::now();
+    mgr.commands("cursor", None).await.unwrap();
+    assert!(started.elapsed() < Duration::from_secs(10), "discovery should time out quickly in tests");
+    let cursor = mgr.providers().into_iter().find(|p| p.id == "cursor").unwrap();
+    assert!(!cursor.config.iter().any(|o| o.category.as_deref() == Some("model")));
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn discovered_effort_levels_fill_models_no_session_has_reported() {
     let tmp = tempfile::tempdir().unwrap();
@@ -2770,3 +2868,223 @@ async fn rolling_back_restores_the_start_of_the_task_and_keeps_the_users_own_edi
     mgr.delete(&task.id, false).await.unwrap();
     assert!(!dir.join("store").join(format!("{}.before", task.id)).exists());
 }
+
+/// A git repository in a temporary folder, for local tasks whose checkout moves under them.
+struct Checkout {
+    _tmp: tempfile::TempDir,
+    dir: PathBuf,
+}
+
+impl Checkout {
+    fn new() -> Self {
+        let tmp = tempfile::tempdir().unwrap();
+        let dir = dunce::canonicalize(tmp.path()).unwrap();
+        let checkout = Self { _tmp: tmp, dir };
+        checkout.git(&["init", "-q", "-b", "main"]);
+        checkout.git(&["config", "core.autocrlf", "false"]);
+        checkout.write(".gitignore", "store/\nworktrees/\nagents/\nmodels.json\n");
+        checkout
+    }
+
+    fn git(&self, args: &[&str]) {
+        let ok = std::process::Command::new("git")
+            .args(["-c", "user.name=t", "-c", "user.email=t@t", "-c", "commit.gpgsign=false"])
+            .args(args)
+            .current_dir(&self.dir)
+            .status()
+            .unwrap()
+            .success();
+        assert!(ok, "{args:?}");
+    }
+
+    fn commit(&self, message: &str) {
+        self.git(&["add", "."]);
+        self.git(&["commit", "-q", "-m", message]);
+    }
+
+    fn write(&self, rel: &str, text: &str) {
+        std::fs::write(self.dir.join(rel), text).unwrap();
+    }
+
+    fn read(&self, rel: &str) -> String {
+        std::fs::read_to_string(self.dir.join(rel)).unwrap()
+    }
+
+    /// A local task, stopped so it can be rolled back.
+    async fn task(&self) -> (AgentManager, AgentTask) {
+        let mgr = manager(&self.dir, Arc::new(FakeAgent::default()));
+        let task = mgr
+            .create(NewAgentTask {
+                project_root: None,
+                prompt: text("Hello"),
+                provider: "claude".into(),
+                config: Vec::new(),
+                isolation: Isolation::Local,
+                base: None,
+            })
+            .await
+            .unwrap();
+        wait_for(&mgr, &task.id, AgentStatus::NeedsInput).await;
+        mgr.cancel(&task.id, None).unwrap();
+        wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+        (mgr, task)
+    }
+}
+
+async fn changed(mgr: &AgentManager, id: &str) -> Vec<String> {
+    mgr.changes(id).await.unwrap().into_iter().map(|c| c.rel_path).collect()
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn work_uncommitted_by_a_reset_during_a_local_task_is_not_rolled_back() {
+    let repo = Checkout::new();
+    repo.write("a.txt", "base\n");
+    repo.write("mine.txt", "base\n");
+    repo.commit("init");
+    repo.write("mine.txt", "my work\n");
+    repo.commit("my work");
+    let (mgr, task) = repo.task().await;
+    repo.write("a.txt", "agent\n");
+    // The user takes the last commit back into the working tree (`git reset --soft`, an
+    // undone commit): its changes are the user's, not the agent's.
+    repo.git(&["reset", "-q", "--soft", "HEAD~1"]);
+    assert_eq!(changed(&mgr, &task.id).await, ["a.txt"]);
+
+    let base = mgr.base_text(&task.id, repo.dir.join("a.txt")).await.unwrap();
+    assert_eq!(base.as_deref(), Some("base\n"));
+    mgr.rollback_changes(&task.id, None).await.unwrap();
+    assert_eq!(repo.read("a.txt"), "base\n");
+    assert_eq!(repo.read("mine.txt"), "my work\n", "the user's work survives the rollback");
+    assert!(changed(&mgr, &task.id).await.is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_branch_switched_to_during_a_local_task_is_left_alone() {
+    let repo = Checkout::new();
+    repo.write("a.txt", "base\n");
+    repo.write("other.txt", "base\n");
+    repo.commit("init");
+    repo.git(&["checkout", "-q", "-b", "feature"]);
+    repo.write("other.txt", "feature\n");
+    repo.write("only-feature.txt", "feature\n");
+    repo.commit("feature");
+    repo.git(&["checkout", "-q", "main"]);
+    repo.write("only-main.txt", "main\n");
+    repo.commit("main");
+    let (mgr, task) = repo.task().await;
+    repo.write("a.txt", "agent\n");
+    // The agent's uncommitted edit comes along to a branch that doesn't contain the task's start.
+    repo.git(&["checkout", "-q", "feature"]);
+    assert_eq!(changed(&mgr, &task.id).await, ["a.txt"]);
+
+    mgr.rollback_changes(&task.id, None).await.unwrap();
+    assert_eq!(repo.read("a.txt"), "base\n");
+    assert_eq!(repo.read("other.txt"), "feature\n");
+    assert_eq!(repo.read("only-feature.txt"), "feature\n");
+    assert!(!repo.dir.join("only-main.txt").exists());
+    assert!(changed(&mgr, &task.id).await.is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn commits_made_during_a_local_task_are_kept_by_its_rollback() {
+    let repo = Checkout::new();
+    repo.write("a.txt", "base\n");
+    repo.commit("init");
+    let (mgr, task) = repo.task().await;
+    repo.write("a.txt", "agent\n");
+    repo.write("b.txt", "agent\n");
+    // The user commits what the agent did to `a.txt` so far: it drops out of the task's changes.
+    repo.git(&["add", "a.txt"]);
+    repo.git(&["commit", "-q", "-m", "keep"]);
+    assert_eq!(changed(&mgr, &task.id).await, ["b.txt"]);
+    repo.write("a.txt", "agent\nagain\n");
+    assert_eq!(changed(&mgr, &task.id).await, ["a.txt", "b.txt"]);
+
+    mgr.rollback_changes(&task.id, None).await.unwrap();
+    assert_eq!(repo.read("a.txt"), "agent\n", "back to the commit, not to before it");
+    assert!(!repo.dir.join("b.txt").exists());
+    assert!(changed(&mgr, &task.id).await.is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_local_task_in_a_repository_without_commits_lists_and_rolls_back_its_changes() {
+    let repo = Checkout::new();
+    repo.write("mine.txt", "mine\n");
+    let (mgr, task) = repo.task().await;
+    repo.write("new.txt", "agent\n");
+    assert_eq!(changed(&mgr, &task.id).await, ["new.txt"]);
+    assert_eq!(mgr.base_text(&task.id, repo.dir.join("new.txt")).await.unwrap(), None);
+
+    mgr.rollback_changes(&task.id, None).await.unwrap();
+    assert!(!repo.dir.join("new.txt").exists());
+    assert_eq!(repo.read("mine.txt"), "mine\n");
+    assert!(changed(&mgr, &task.id).await.is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn security_policy_auto_approves_whitelist_and_rejects_blacklist() {
+    use ide_core::settings::AgentSecuritySettings;
+
+    // 1. Whitelist auto-approves "cargo test" without waiting for manual respond().
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent);
+    mgr.set_security_hook(Arc::new(|| AgentSecuritySettings {
+        allowed_commands: vec!["cargo test".into()],
+        blocked_commands: vec!["rm -rf *".into()],
+    }));
+    let task = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("run tests"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    let entries = mgr.entries(&task.id, None).unwrap();
+    assert!(
+        entries.iter().any(|e| matches!(e, AgentEntry::Agent { text } if text.contains("chose yes"))),
+        "{entries:?}"
+    );
+    assert!(
+        entries.iter().any(|e| matches!(
+            e,
+            AgentEntry::Permission { chosen: Some(c), .. } if c.contains("whitelisted")
+        )),
+        "{entries:?}"
+    );
+
+    // 2. Blacklist auto-rejects "cargo test" when matched by blocked_commands.
+    mgr.set_security_hook(Arc::new(|| AgentSecuritySettings {
+        allowed_commands: vec!["cargo test".into()],
+        blocked_commands: vec!["cargo test*".into()],
+    }));
+    let blocked_task = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("run blocked"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &blocked_task.id, AgentStatus::Ready).await;
+    let blocked_entries = mgr.entries(&blocked_task.id, None).unwrap();
+    assert!(
+        blocked_entries.iter().any(|e| matches!(e, AgentEntry::Agent { text } if text.contains("chose no"))),
+        "{blocked_entries:?}"
+    );
+    assert!(
+        blocked_entries.iter().any(|e| matches!(
+            e,
+            AgentEntry::Permission { chosen: Some(c), .. } if c.contains("Blocked by policy")
+        )),
+        "{blocked_entries:?}"
+    );
+}

crates/ide-agent/src/worktree.rs

@@ -117,14 +117,136 @@ pub(crate) fn changes(cwd: &Path, base: &str) -> IdeResult<Vec<AgentChange>> {
     let tracked: std::collections::HashSet<String> = out.iter().map(|c| c.rel_path.clone()).collect();
     for s in repo.status()? {
         if s.unstaged == Some(ChangeKind::Untracked) && !tracked.contains(&s.rel_path) {
-            let added = std::fs::read_to_string(&*s.path).map_or(0, |t| t.lines().count() as u32);
-            out.push(AgentChange { path: s.path, rel_path: s.rel_path, kind: ChangeKind::Added, added, removed: 0 });
+            out.push(added(s.path, s.rel_path));
         }
     }
     out.sort_by(|a, b| a.rel_path.cmp(&b.rel_path));
     Ok(out)
 }
 
+fn added(path: IpcPath, rel_path: String) -> AgentChange {
+    let added = std::fs::read_to_string(&*path).map_or(0, |t| t.lines().count() as u32);
+    AgentChange { path, rel_path, kind: ChangeKind::Added, added, removed: 0 }
+}
+
+/// Where a task works and what its changes are measured against.
+pub(crate) enum TaskBase {
+    /// A worktree of its own: everything since the commit it was created from, the agent's
+    /// own commits included.
+    Worktree { cwd: PathBuf, base: String },
+    /// The project's checkout, where the user works and commits too. `start` is the commit it
+    /// started from (`None` in a repository without commits, or an imported session).
+    Local { cwd: PathBuf, start: Option<String> },
+}
+
+impl TaskBase {
+    pub(crate) fn cwd(&self) -> &Path {
+        match self {
+            Self::Worktree { cwd, .. } | Self::Local { cwd, .. } => cwd,
+        }
+    }
+
+    /// The files the task changed, less those changed before it started and untouched since.
+    pub(crate) fn changes(&self, before: &BTreeMap<String, Stamp>) -> IdeResult<Vec<AgentChange>> {
+        let (cwd, start) = match self {
+            Self::Worktree { cwd, base } => return Ok(without_untouched(changes(cwd, base)?, before)),
+            Self::Local { cwd, start } => (cwd, start.as_deref()),
+        };
+        let Some(repo) = discover(cwd)? else { return Ok(Vec::new()) };
+        // What is uncommitted, as the Commit tool window lists it: commits made since the task
+        // started drop out.
+        let head = repo.branch_info()?.head_commit;
+        let listed = match &head {
+            Some(head) => changes(cwd, head)?,
+            None => {
+                let mut all: Vec<AgentChange> = repo
+                    .status()?
+                    .into_iter()
+                    .filter(|s| s.path.is_file())
+                    .map(|s| added(s.path, s.rel_path))
+                    .collect();
+                all.sort_by(|a, b| a.rel_path.cmp(&b.rel_path));
+                all
+            }
+        };
+        let listed = without_untouched(listed, before);
+        let Some(start) = start.filter(|s| head.as_deref() != Some(*s)) else { return Ok(listed) };
+        // HEAD moved (a reset, a checkout, a pull): a file that is as it was when the task
+        // started is the user's doing, not the task's.
+        Ok(listed
+            .into_iter()
+            .filter(|c| {
+                before.contains_key(&c.rel_path)
+                    || !repo.file_bytes_at(&c.path.0, Some(start)).is_ok_and(|at| at == std::fs::read(&c.path.0).ok())
+            })
+            .collect())
+    }
+
+    /// The revision the task's changed files go back to on rollback, and are compared with:
+    /// the commit the task started from, or the current `HEAD` once the user committed on top
+    /// of it, so those commits stay. `None` while the repository has no commits.
+    pub(crate) fn rev(&self) -> IdeResult<Option<String>> {
+        let (cwd, start) = match self {
+            Self::Worktree { base, .. } => return Ok(Some(base.clone())),
+            Self::Local { cwd, start } => (cwd, start.as_deref()),
+        };
+        let Some(repo) = discover(cwd)? else { return Ok(None) };
+        let head = repo.branch_info()?.head_commit;
+        // A start commit git no longer knows (garbage-collected) can't be gone back to.
+        let start = start.filter(|s| repo.merge_base(s, s).ok().flatten().is_some());
+        Ok(match (start, head) {
+            (Some(start), Some(head)) if start != head && repo.merge_base(start, &head)?.as_deref() != Some(start) => {
+                Some(start.to_owned())
+            }
+            (start, head) => head.or_else(|| start.map(str::to_owned)),
+        })
+    }
+}
+
+/// Copies the task's `changes` (against `base`) from the worktree `cwd` into the
+/// local checkout `root`, uncommitted: the user reviews and commits them with the
+/// VCS tools. Files the checkout changed itself are left alone and reported, so
+/// accepting never destroys the user's own edits. Returns accepted and skipped paths.
+pub(crate) fn accept(
+    root: &Path,
+    cwd: &Path,
+    base: &str,
+    changes: &[AgentChange],
+) -> IdeResult<crate::AgentAcceptOutcome> {
+    let repo = repo_at(cwd)?;
+    let mut accepted = Vec::with_capacity(changes.len());
+    let mut skipped = Vec::new();
+    for change in changes {
+        let local = root.join(&change.rel_path);
+        let base_bytes = repo.file_bytes_at(&change.path.0, Some(base))?;
+        let current = std::fs::read(&change.path.0).ok();
+        let local_bytes = std::fs::read(&local).ok();
+        if local_bytes == current {
+            accepted.push(change.rel_path.clone());
+        } else if local_bytes == base_bytes {
+            match current {
+                Some(bytes) => {
+                    if let Some(parent) = local.parent() {
+                        std::fs::create_dir_all(parent)?;
+                    }
+                    std::fs::write(&local, bytes)?;
+                }
+                None => match std::fs::remove_file(&local) {
+                    Err(e) if e.kind() != std::io::ErrorKind::NotFound => return Err(e.into()),
+                    _ => {}
+                },
+            }
+            accepted.push(change.rel_path.clone());
+        } else {
+            skipped.push(crate::AgentAcceptSkipped {
+                path: change.rel_path.clone(),
+                reason: "the checkout has changes of its own to it; accept it by hand".to_owned(),
+            });
+        }
+    }
+    Ok(crate::AgentAcceptOutcome { accepted, skipped })
+}
+
 /// Size and modification time of a file, `None` once it is gone.
 pub(crate) type Stamp = Option<(u64, u128)>;
 
@@ -176,11 +298,11 @@ pub(crate) fn save_before(cwd: &Path, before: &BTreeMap<String, Stamp>, dir: &Pa
 }
 
 /// Rolls `change` back: to the copy saved when the task started when the file had changes
-/// then (`before`, `saved` holding the copies), otherwise to `base` (removed when `base`
-/// lacks it).
+/// then (`before`, `saved` holding the copies), otherwise to `rev` (removed when `rev` lacks
+/// it, or when there is no `rev`: the repository had no commits).
 pub(crate) fn restore(
     cwd: &Path,
-    base: &str,
+    rev: Option<&str>,
     change: &AgentChange,
     before: &BTreeMap<String, Stamp>,
     saved: Option<&Path>,
@@ -198,10 +320,13 @@ pub(crate) fn restore(
                 })?;
             Some(std::fs::read(copy)?)
         }
-        None => {
-            let repo = Repo::discover(cwd)?.ok_or_else(|| IdeError::invalid("not in a git repository"))?;
-            repo.file_bytes_at(path, Some(base))?
-        }
+        None => match rev {
+            Some(rev) => {
+                let repo = Repo::discover(cwd)?.ok_or_else(|| IdeError::invalid("not in a git repository"))?;
+                repo.file_bytes_at(path, Some(rev))?
+            }
+            None => None,
+        },
     };
     match content {
         Some(bytes) => {
@@ -406,4 +531,94 @@ mod tests {
         assert!(remove(&repo, &tmp.path().join("wt"), &elsewhere).is_err());
         assert!(elsewhere.join("keep.txt").exists());
     }
+
+    fn accept_repo() -> (tempfile::TempDir, PathBuf, Created) {
+        let tmp = tempfile::tempdir().unwrap();
+        let repo = tmp.path().join("repo");
+        std::fs::create_dir(&repo).unwrap();
+        git(&repo, &["init", "-q", "-b", "main"]);
+        std::fs::write(repo.join("a.txt"), "one\ntwo\n").unwrap();
+        std::fs::write(repo.join("gone.txt"), "bye\n").unwrap();
+        git(&repo, &["add", "."]);
+        git(&repo, &["commit", "-q", "-m", "init"]);
+        let created = create(&repo, &tmp.path().join("wt"), "Edit A", None).unwrap();
+        (tmp, repo, created)
+    }
+
+    fn listed(cwd: &Path, base: &str) -> Vec<AgentChange> {
+        without_untouched(changes(cwd, base).unwrap(), &BTreeMap::new())
+    }
+
+    #[test]
+    fn accept_copies_new_modified_and_deleted_files_into_the_checkout() {
+        let (_tmp, repo, created) = accept_repo();
+        std::fs::write(created.path.join("a.txt"), "one\nTWO\n").unwrap();
+        std::fs::write(created.path.join("new.txt"), "x\n").unwrap();
+        std::fs::remove_file(created.path.join("gone.txt")).unwrap();
+
+        let outcome =
+            accept(&repo, &created.path, &created.base_commit, &listed(&created.path, &created.base_commit)).unwrap();
+        assert!(outcome.skipped.is_empty());
+        assert_eq!(outcome.accepted, ["a.txt", "gone.txt", "new.txt"]);
+        assert_eq!(std::fs::read_to_string(repo.join("a.txt")).unwrap(), "one\nTWO\n");
+        assert_eq!(std::fs::read_to_string(repo.join("new.txt")).unwrap(), "x\n");
+        assert!(!repo.join("gone.txt").exists());
+
+        // Accepting again changes nothing: the checkout already matches.
+        let again =
+            accept(&repo, &created.path, &created.base_commit, &listed(&created.path, &created.base_commit)).unwrap();
+        assert!(again.skipped.is_empty());
+        assert_eq!(again.accepted, ["a.txt", "gone.txt", "new.txt"]);
+    }
+
+    #[test]
+    fn a_local_task_goes_back_to_its_start_unless_the_user_committed_on_top_of_it() {
+        let tmp = tempfile::tempdir().unwrap();
+        let repo = tmp.path().join("repo");
+        std::fs::create_dir(&repo).unwrap();
+        git(&repo, &["init", "-q", "-b", "main"]);
+        let local = |start: Option<&str>| TaskBase::Local { cwd: repo.clone(), start: start.map(str::to_owned) };
+        let head = || head_of(&repo).unwrap().1;
+        let commit = |name: &str| {
+            std::fs::write(repo.join(name), "x\n").unwrap();
+            git(&repo, &["add", "."]);
+            git(&repo, &["commit", "-q", "-m", name]);
+            head_of(&repo).unwrap().1
+        };
+
+        assert_eq!(local(None).rev().unwrap(), None, "no commits yet");
+        let first = commit("a.txt");
+        assert_eq!(local(None).rev().unwrap(), Some(first.clone()), "an imported session: HEAD");
+        let start = commit("b.txt");
+        assert_eq!(local(Some(&start)).rev().unwrap(), Some(start.clone()), "HEAD where it started");
+        let ahead = commit("c.txt");
+        assert_eq!(local(Some(&start)).rev().unwrap(), Some(ahead), "committed on top: HEAD");
+        git(&repo, &["reset", "-q", "--soft", &first]);
+        assert_eq!(local(Some(&start)).rev().unwrap(), Some(start.clone()), "moved back: the start");
+        git(&repo, &["checkout", "-q", "-b", "side"]);
+        commit("d.txt");
+        assert_eq!(local(Some(&start)).rev().unwrap(), Some(start.clone()), "another branch: the start");
+        let gone = "0123456789abcdef0123456789abcdef01234567";
+        assert_eq!(local(Some(gone)).rev().unwrap(), Some(head()), "an unknown start: HEAD");
+        let worktree = TaskBase::Worktree { cwd: repo.clone(), base: start.clone() };
+        assert_eq!(worktree.rev().unwrap(), Some(start));
+    }
+
+    #[test]
+    fn accept_leaves_files_the_checkout_changed_itself() {
+        let (_tmp, repo, created) = accept_repo();
+        std::fs::write(created.path.join("a.txt"), "one\nTWO\n").unwrap();
+        std::fs::write(created.path.join("gone.txt"), "bye\nbye\n").unwrap();
+        std::fs::write(repo.join("a.txt"), "one\nMINE\n").unwrap();
+
+        let outcome =
+            accept(&repo, &created.path, &created.base_commit, &listed(&created.path, &created.base_commit)).unwrap();
+        assert_eq!(outcome.accepted, ["gone.txt"]);
+        assert_eq!(outcome.skipped.len(), 1);
+        assert_eq!(outcome.skipped[0].path, "a.txt");
+        assert!(!outcome.skipped[0].reason.is_empty());
+        // The user's own edit survives; the other file comes over.
+        assert_eq!(std::fs::read_to_string(repo.join("a.txt")).unwrap(), "one\nMINE\n");
+        assert_eq!(std::fs::read_to_string(repo.join("gone.txt")).unwrap(), "bye\nbye\n");
+    }
 }

crates/ide-build/src/compile/mod.rs

@@ -266,6 +266,11 @@ pub(super) fn maven_steps(
         BuildKind::Rebuild => &["clean", "test-compile"],
         BuildKind::Artifacts => &["package", "-DskipTests"],
     };
+    // The IDE's compile builds are not coverage runs. JaCoCo's offline `instrument`
+    // rewrites target/classes in `process-classes`; `jacoco.skip` prevents that in this
+    // build. It does not restore classes instrumented by an earlier build: Rebuild's
+    // `clean` removes those, while an incremental Build can still reuse them.
+    let skip_jacoco = matches!(kind, BuildKind::Build | BuildKind::Rebuild);
     let tops: Vec<&maven::MavenProject> = m.projects.iter().filter(|p| !p.aggregated).collect();
     if tops.is_empty() {
         return Err(IdeError::not_found("no Maven project found"));
@@ -278,6 +283,9 @@ pub(super) fn maven_steps(
             Format::Maven,
         );
         s.args.extend(p.options.iter().cloned());
+        if skip_jacoco {
+            s.args.push("-Djacoco.skip=true".into());
+        }
         s.args.extend(extra.iter().cloned());
         s.args.extend(goals.iter().map(|g| (*g).to_owned()));
         s.env = p.env.clone();
@@ -1041,6 +1049,22 @@ mod tests {
         std::fs::write(p, text).unwrap();
     }
 
+    #[test]
+    fn maven_compile_steps_skip_jacoco_but_artifacts_do_not() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().join("demo");
+        write(&root, "pom.xml", "<project><artifactId>demo</artifactId></project>");
+        let model = crate::load(&root, &tmp.path().join("cache"), None);
+        for (kind, expected) in [(BuildKind::Build, true), (BuildKind::Rebuild, true), (BuildKind::Artifacts, false)] {
+            let plan = plan(&root, &model, kind, None, None).unwrap();
+            assert_eq!(
+                plan.steps[0].args.iter().any(|arg| arg == "-Djacoco.skip=true"),
+                expected,
+                "{kind:?}: {plan:?}"
+            );
+        }
+    }
+
     #[test]
     fn plans_per_build_system() {
         let tmp = tempfile::tempdir().unwrap();
@@ -1057,7 +1081,10 @@ mod tests {
         assert_eq!(p.system, BuildSystem::Maven);
         assert_eq!(p.title, "demo");
         assert_eq!(p.steps.len(), 1);
-        assert_eq!(p.steps[0].args, ["-B", "-Dstyle.color=never", maven::LOCAL_REPO_TRACKING_ARG, "test-compile"]);
+        assert_eq!(
+            p.steps[0].args,
+            ["-B", "-Dstyle.color=never", maven::LOCAL_REPO_TRACKING_ARG, "-Djacoco.skip=true", "test-compile"]
+        );
         let p = plan(&root, &model, BuildKind::Rebuild, Some(&root.join("core/src/main/java/A.java")), None).unwrap();
         assert_eq!(
             p.steps[0].args,
@@ -1065,6 +1092,7 @@ mod tests {
                 "-B",
                 "-Dstyle.color=never",
                 maven::LOCAL_REPO_TRACKING_ARG,
+                "-Djacoco.skip=true",
                 "-pl",
                 "core",
                 "-am",
@@ -1353,6 +1381,7 @@ mod tests {
                     maven::LOCAL_REPO_TRACKING_ARG,
                     "-s",
                     "settings.xml",
+                    "-Djacoco.skip=true",
                     "-pl",
                     "app",
                     "-am",
@@ -1369,6 +1398,7 @@ mod tests {
                     maven::LOCAL_REPO_TRACKING_ARG,
                     "-s",
                     "settings.xml",
+                    "-Djacoco.skip=true",
                     "-pl",
                     "app",
                     "-am",

crates/ide-build/src/kotlin_bridge.rs

@@ -536,6 +536,7 @@ mod tests {
                         crate::maven::LOCAL_REPO_TRACKING_ARG,
                         "-o",
                         "-Peditor",
+                        "-Djacoco.skip=true",
                         "test-compile"
                     ]
                 );

crates/ide-core/src/event.rs

@@ -275,6 +275,11 @@ pub enum DebugEvent {
     },
     /// The session's capabilities changed after it started: fetch them again.
     Capabilities,
+    /// The adapter's `invalidated` event: what it shows for `areas` (`all`, `stacks`, `threads`,
+    /// `variables`; empty means all) is stale and has to be fetched again.
+    Invalidated {
+        areas: Vec<String>,
+    },
     JvmBackend {
         state: JvmBackendState,
     },
@@ -330,4 +335,12 @@ mod tests {
         );
         assert_eq!(serde_json::to_value(DebugEvent::Capabilities).unwrap(), json!({"kind": "capabilities"}));
     }
+
+    #[test]
+    fn invalidated_event_json_shape() {
+        assert_eq!(
+            serde_json::to_value(DebugEvent::Invalidated { areas: vec!["variables".into()] }).unwrap(),
+            json!({"kind": "invalidated", "areas": ["variables"]})
+        );
+    }
 }

crates/ide-core/src/ipc_path.rs

@@ -12,11 +12,16 @@ use std::path::{Path, PathBuf};
 
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
-/// `p` as the UI sees it: `C:\a\b` and `\\?\C:\a\b` become `C:/a/b`.
+/// `p` as the UI sees it: `C:\a\b`, `c:\a\b` and `\\?\C:\a\b` become `C:/a/b`.
 pub fn to_ipc(p: &Path) -> String {
     #[cfg(windows)]
     {
-        dunce::simplified(p).to_string_lossy().replace('\\', "/")
+        let mut s = dunce::simplified(p).to_string_lossy().replace('\\', "/");
+        // The UI compares path strings; a drive letter is case-insensitive.
+        if s.as_bytes().get(1) == Some(&b':') {
+            s[..1].make_ascii_uppercase();
+        }
+        s
     }
     #[cfg(not(windows))]
     {
@@ -144,5 +149,8 @@ mod tests {
         assert_eq!(to_ipc(Path::new(r"\\?\C:\a\b")), "C:/a/b");
         assert_eq!(to_ipc(&Path::new("C:/a").join("b")), "C:/a/b");
         assert_eq!(serde_json::to_string(&IpcPath::from(r"C:\a\b")).unwrap(), r#""C:/a/b""#);
+        assert_eq!(to_ipc(Path::new(r"c:\a\b")), "C:/a/b");
+        assert_eq!(to_ipc(Path::new(r"\\?\d:\a")), "D:/a");
+        assert_eq!(to_ipc(Path::new(r"\\server\share\a")), "//server/share/a");
     }
 }

crates/ide-core/src/settings.rs

@@ -63,6 +63,8 @@ pub struct Settings {
     pub agents: AgentSettings,
     /// Agents › MCP Server (global only).
     pub mcp_server: McpServerSettings,
+    /// Tools › Agents: Command Execution Policy.
+    pub agent_security: AgentSecuritySettings,
     /// Plugin settings (`[contributes.settings]`): plugin id → its values by key.
     #[specta(type = BTreeMap<String, BTreeMap<String, specta_typescript::Unknown>>)]
     pub plugins: BTreeMap<String, serde_json::Map<String, serde_json::Value>>,
@@ -411,6 +413,7 @@ impl Default for Settings {
             cmake: CMakeSettings::default(),
             agents: AgentSettings::default(),
             mcp_server: McpServerSettings::default(),
+            agent_security: AgentSecuritySettings::default(),
             plugins: BTreeMap::new(),
         }
     }

crates/ide-core/src/text.rs

@@ -138,8 +138,11 @@ impl WorkspaceEdit {
                         continue;
                     }
                     *expected = expected.or(version);
+                    // Repeats within one entry are intended (LSP inserts at one position
+                    // apply in order); only an alias entry repeats what is already merged.
+                    let merged = own.len();
                     for edit in edits {
-                        if !own.contains(&edit) {
+                        if !own[..merged].contains(&edit) {
                             own.push(edit);
                         }
                     }
@@ -277,10 +280,40 @@ pub struct OutlineItem {
 /// Fuzzy-match highlight: indices (in chars of the displayed string) that matched.
 pub type MatchIndices = Vec<u32>;
 
-#[cfg(all(test, unix))]
+#[cfg(test)]
 mod workspace_edit_tests {
     use super::*;
 
+    #[test]
+    fn repeated_edits_within_one_entry_survive_but_repeats_across_entries_do_not() {
+        let path = PathBuf::from("missing-dir/main.ts");
+        let at = |line, text: &str| TextEdit {
+            range: Range::new(Pos::new(line, 0), Pos::new(line, 0)),
+            new_text: text.into(),
+        };
+        let entry = |edits: Vec<TextEdit>| FileEdit::Edit { path: path.clone().into(), edits, version: None };
+        let (nl, brace, other) = (at(0, "\n"), at(1, "}"), at(2, "x"));
+        for (entries, expected) in [
+            (vec![vec![nl.clone(), nl.clone()]], vec![nl.clone(), nl.clone()]),
+            (vec![vec![brace.clone(), nl.clone(), brace.clone()]], vec![brace.clone(), nl.clone(), brace.clone()]),
+            (vec![vec![nl.clone(), nl.clone()], vec![nl.clone(), nl.clone()]], vec![nl.clone(), nl.clone()]),
+            (vec![vec![nl.clone()], vec![nl.clone(), other.clone()]], vec![nl.clone(), other.clone()]),
+            (
+                vec![vec![nl.clone()], vec![other.clone(), other.clone()]],
+                vec![nl.clone(), other.clone(), other.clone()],
+            ),
+        ] {
+            let mut workspace =
+                WorkspaceEdit { files: entries.clone().into_iter().map(entry).collect(), ..Default::default() };
+            workspace.deduplicate();
+            assert_eq!(workspace.files, [entry(expected.clone())], "{entries:?}");
+            let once = workspace.clone();
+            workspace.deduplicate();
+            assert_eq!(workspace, once, "{entries:?}");
+        }
+    }
+
+    #[cfg(unix)]
     #[test]
     fn aliases_are_one_edit_but_resource_operations_preserve_order() {
         let dir = tempfile::tempdir().unwrap();

crates/ide-core/src/workflow_settings.rs

@@ -412,3 +412,30 @@ impl Default for ExternalTool {
         }
     }
 }
+
+/// Tools › Agents: Command Execution Policy (whitelist and blacklist patterns).
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct AgentSecuritySettings {
+    /// Commands or patterns (`git status*`, `pwd`) automatically approved without prompting.
+    pub allowed_commands: Vec<String>,
+    /// Commands or patterns (`rm -rf *`, `mkfs*`) automatically rejected.
+    pub blocked_commands: Vec<String>,
+}
+
+impl Default for AgentSecuritySettings {
+    fn default() -> Self {
+        Self {
+            allowed_commands: Vec::new(),
+            blocked_commands: vec![
+                "rm -rf *".into(),
+                "rm -rf /".into(),
+                "mkfs*".into(),
+                "dd *".into(),
+                ":(){ :|:& };:".into(),
+                "shutdown*".into(),
+                "reboot*".into(),
+            ],
+        }
+    }
+}

crates/ide-dap/src/adapter.rs

@@ -72,6 +72,13 @@ fn builtin(adapter: &str) -> Option<DebuggerConfig> {
             "stdio",
             "Install Kotlin Debug Adapter in Settings › Languages & Frameworks › Language Servers",
         ),
+        // Inside the language server: reached through `debugServer`, never started.
+        "kotlin-lsp" => cfg(
+            "kotlin-lsp",
+            &[],
+            "tcp",
+            "Install JetBrains Kotlin LSP in Settings › Languages & Frameworks › Language Servers",
+        ),
         // Windows installs `python.exe`; `python3.exe` there is at most a Store alias.
         "debugpy" => cfg(
             if cfg!(windows) { "python" } else { "python3" },

crates/ide-dap/src/jvm_memory/mod.rs

@@ -29,7 +29,7 @@ pub(crate) use scan::watch_for_attached_jvm;
 pub(crate) use scan::{JvmFinder, attach_target, find_attached_jvm, find_local_jvm, local_jdwp_port};
 use snapshot::{AttachProbe, JdkProbe, take_snapshot};
 
-pub const JVM_MEMORY_ADAPTERS: &[&str] = &["java-debug", crate::kotlin::ADAPTER];
+pub const JVM_MEMORY_ADAPTERS: &[&str] = &["java-debug", crate::kotlin::ADAPTER, crate::kotlin_lsp::ADAPTER];
 pub const HISTOGRAM_TIMEOUT: Duration = Duration::from_secs(10);
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]

crates/ide-dap/src/kotlin.rs

@@ -9,11 +9,15 @@ use std::{
 
 pub const ADAPTER: &str = "kotlin-debug-adapter";
 
-/// The adapter attaches to a JVM the IDE starts, through the JDWP link. It resumes the VM while
-/// constructing its debuggee, before its breakpoint hooks exist, so the link holds resumes back
-/// until the attach is done.
-pub(crate) fn link_options() -> ide_jdwp::LinkOptions {
-    ide_jdwp::LinkOptions { hold_resumes: true }
+/// fwcd's adapter or kotlin-lsp's: both debug a JVM the IDE starts, through the JDWP link.
+pub fn is_kotlin(adapter: &str) -> bool {
+    adapter == ADAPTER || adapter == crate::kotlin_lsp::ADAPTER
+}
+
+/// fwcd's adapter resumes the VM while constructing its debuggee, before its breakpoint hooks
+/// exist, so only its link holds resumes back until the attach is done.
+pub(crate) fn link_options(adapter: &str) -> ide_jdwp::LinkOptions {
+    ide_jdwp::LinkOptions { hold_resumes: adapter == ADAPTER }
 }
 
 pub struct SourceMirror {

crates/ide-dap/src/kotlin_lsp.rs

@@ -0,0 +1,147 @@
+//! JetBrains kotlin-lsp's debugger: a DAP server inside the language server, reached through
+//! the `debugServer` port it opens once the project is imported.
+//!
+//! Known limits, with no guard here: an evaluate that calls a function with a breakpoint, right
+//! after a step over a suspension point, loses every later stop at that breakpoint; while
+//! stepping, breakpoints hit by other coroutines are skipped.
+
+use ide_core::{IdeError, IdeResult};
+use parking_lot::Mutex;
+use std::collections::HashSet;
+use std::path::PathBuf;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+pub const ADAPTER: &str = "kotlin-lsp";
+/// The `adapterID` its debug server expects in `initialize`.
+pub const DAP_ADAPTER_ID: &str = "intellij_jvm";
+
+/// The path of a `file:` URI, as kotlin-lsp reports some sources (percent-encoded); `None` for
+/// anything else, including a URI naming another host.
+pub(crate) fn source_path(path: &str) -> Option<PathBuf> {
+    let rest = path.strip_prefix("file:")?;
+    let path = match rest.strip_prefix("//") {
+        Some(authority) => {
+            let slash = authority.find('/')?;
+            if !matches!(&authority[..slash], "" | "localhost") {
+                return None;
+            }
+            &authority[slash..]
+        }
+        None => rest,
+    };
+    let decoded = percent_encoding::percent_decode_str(path).decode_utf8().ok()?;
+    // `/C:/p/App.kt` on Windows.
+    let decoded = match decoded.strip_prefix('/') {
+        Some(drive) if cfg!(windows) && drive.as_bytes().get(1) == Some(&b':') => drive,
+        _ => &decoded,
+    };
+    Some(PathBuf::from(decoded))
+}
+
+pub(crate) fn frame_name(name: &str) -> &str {
+    name.strip_prefix("at ").unwrap_or(name)
+}
+
+/// What kotlin-lsp's DAP server does unlike other adapters.
+///
+/// It never answers a request that carries a thread id from an earlier stop (K1 G4), so such a
+/// request would wait out `REQUEST_TIMEOUT`: [`Self::check_thread`] refuses it first. Only thread
+/// ids were measured; a stale `frameId` or `variablesReference` may wait the same way. A step
+/// ends with `reason: "breakpoint"`; a real breakpoint hit during a step is then reported as a
+/// step too, since the stop carries neither `hitBreakpointIds` nor a description.
+#[derive(Default)]
+pub(crate) struct Quirks {
+    step_pending: AtomicBool,
+    /// The stop (a `Suspension` ticket) and the thread ids seen in it.
+    threads: Mutex<(u64, HashSet<i64>)>,
+}
+
+impl Quirks {
+    /// Before `next`, `stepIn`, `stepOut` or a forced step.
+    pub fn step_sent(&self) {
+        self.step_pending.store(true, Ordering::Release);
+    }
+
+    /// Before `continue` or run to cursor, or after a step request failed.
+    pub fn resume_sent(&self) {
+        self.step_pending.store(false, Ordering::Release);
+    }
+
+    /// The reason to report for a `stopped` event.
+    pub fn stop_reason(&self, reason: String) -> String {
+        let stepped = self.step_pending.swap(false, Ordering::AcqRel);
+        if stepped && reason == "breakpoint" { "step".into() } else { reason }
+    }
+
+    /// Thread ids seen in stop `stop`: a `stopped` event's, or a `threads` reply to a request sent
+    /// during that stop. A reply from an older stop changes nothing.
+    pub fn saw_threads(&self, stop: u64, ids: impl IntoIterator<Item = i64>) {
+        let mut threads = self.threads.lock();
+        if stop > threads.0 {
+            *threads = (stop, ids.into_iter().collect());
+        } else if stop == threads.0 {
+            threads.1.extend(ids);
+        }
+    }
+
+    /// Refuses a thread id that is not one of current stop `stop`'s, once some are known.
+    pub fn check_thread(&self, stop: u64, suspended: bool, id: i64) -> IdeResult<()> {
+        let threads = self.threads.lock();
+        if suspended && threads.0 == stop && !threads.1.is_empty() && !threads.1.contains(&id) {
+            return Err(IdeError::invalid(format!("thread {id} belongs to an earlier stop")));
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::path::Path;
+
+    #[test]
+    fn file_uris_become_paths() {
+        assert_eq!(source_path("file:///p/a%20b/App.kt").as_deref(), Some(Path::new("/p/a b/App.kt")));
+        assert_eq!(source_path("file://localhost/p/x.kt").as_deref(), Some(Path::new("/p/x.kt")));
+        assert_eq!(source_path("/p/x.kt"), None);
+    }
+
+    #[test]
+    fn frame_names_lose_the_at_prefix() {
+        assert_eq!(frame_name("at com.x.AppKt.main(App.kt:13)"), "com.x.AppKt.main(App.kt:13)");
+        assert_eq!(frame_name("main"), "main");
+    }
+
+    #[test]
+    fn only_a_pending_step_turns_a_breakpoint_into_a_step() {
+        let quirks = Quirks::default();
+        quirks.step_sent();
+        assert_eq!(quirks.stop_reason("breakpoint".into()), "step");
+        assert_eq!(quirks.stop_reason("breakpoint".into()), "breakpoint");
+        quirks.step_sent();
+        quirks.resume_sent();
+        assert_eq!(quirks.stop_reason("breakpoint".into()), "breakpoint");
+    }
+
+    #[test]
+    fn threads_are_checked_against_the_current_stop() {
+        let quirks = Quirks::default();
+        quirks.saw_threads(3, [18]);
+        assert!(quirks.check_thread(3, true, 18).is_ok());
+        assert!(quirks.check_thread(3, true, 6).is_err());
+        assert!(quirks.check_thread(4, true, 6).is_ok(), "nothing known about stop 4 yet");
+        assert!(quirks.check_thread(3, false, 6).is_ok());
+    }
+
+    #[test]
+    fn an_older_threads_reply_does_not_change_a_newer_stop() {
+        let quirks = Quirks::default();
+        quirks.saw_threads(4, [2]);
+        quirks.saw_threads(3, [1]);
+        assert!(quirks.check_thread(4, true, 1).is_err());
+        quirks.saw_threads(4, [7]);
+        assert!(quirks.check_thread(4, true, 2).is_ok() && quirks.check_thread(4, true, 7).is_ok());
+        quirks.saw_threads(5, [9]);
+        assert!(quirks.check_thread(5, true, 2).is_err());
+    }
+}

crates/ide-dap/src/lib.rs

@@ -15,6 +15,7 @@ pub mod connection;
 pub mod jdwp;
 mod jvm_memory;
 pub mod kotlin;
+pub mod kotlin_lsp;
 mod session;
 
 use adapter::{AdapterLauncher, AdapterSpec, ProcessLauncher};
@@ -610,9 +611,19 @@ fn unverified(enabled: impl Iterator<Item = bool>) -> Vec<BreakpointState> {
         .collect()
 }
 
-/// Delve compiles the debuggee to `__debug_bin` in the session's cwd (on Windows
-/// `__debug_bin.exe` plus `__debug_bin.exe<digits>` in DAP mode) and removes it on a
-/// graceful exit — a shutdown it doesn't always reach, so the files pile up. Sweep
+/// A step request's outcome; a failed one leaves no step pending, so the next stop keeps its reason.
+fn step_settled(session: &Session, sent: Result<Value, DapError>) -> Result<Value, DapError> {
+    if sent.is_err()
+        && let Some(quirks) = session.kotlin_lsp_quirks()
+    {
+        quirks.resume_sent();
+    }
+    sent
+}
+
+/// Delve compiles the debuggee to `__debug_bin` in the session's cwd (in DAP mode a
+/// temp-file name, `__debug_bin<digits>`; on Windows with `.exe` before the digits) and
+/// removes it on a graceful exit — a shutdown it doesn't always reach, so the files pile up. Sweep
 /// the leftovers once the session is down. Runs after `session_closed`, so Delve
 /// has already exited or been killed and holds no file locks; a leftover of a
 /// still-building run is removed on that run's own shutdown.
@@ -621,14 +632,10 @@ fn remove_delve_binaries(cwd: &Path) {
     for entry in entries.flatten() {
         let name = entry.file_name();
         let Some(name) = name.to_str() else { continue };
-        // Windows writes `__debug_bin.exe` (and `.exe<digits>` in DAP mode); other
-        // platforms keep the bare name. Suffixes like `.go` are user files.
-        let suffix = name.strip_prefix("__debug_bin");
-        let leftover = suffix.is_some_and(|s| {
-            s.is_empty()
-                || s == ".exe"
-                || (s.starts_with(".exe") && s[".exe".len()..].chars().all(|c| c.is_ascii_digit()))
-        });
+        // `__debug_bin`, then `.exe` on Windows, then DAP mode's temp-file digits.
+        // Suffixes like `.go` are user files.
+        let suffix = name.strip_prefix("__debug_bin").map(|s| s.strip_prefix(".exe").unwrap_or(s));
+        let leftover = suffix.is_some_and(|s| s.chars().all(|c| c.is_ascii_digit()));
         if !leftover || entry.file_type().is_ok_and(|t| !t.is_file()) {
             continue;
         }
@@ -981,6 +988,7 @@ impl DebugManager {
             arguments["projectRoot"] = json!(mirror.root());
             *s.kotlin_mirror.lock() = Some(mirror);
         }
+        let is_kotlin_lsp = s.adapter == kotlin_lsp::ADAPTER;
         let caps = s
             .conn
             .request_timeout(
@@ -988,7 +996,7 @@ impl DebugManager {
                 json!({
                     "clientID": "openidea",
                     "clientName": "OpenIDEA",
-                    "adapterID": s.adapter,
+                    "adapterID": if is_kotlin_lsp { kotlin_lsp::DAP_ADAPTER_ID } else { s.adapter.as_str() },
                     "locale": "en",
                     "linesStartAt1": true,
                     "columnsStartAt1": true,
@@ -998,7 +1006,8 @@ impl DebugManager {
                     "supportsRunInTerminalRequest": true,
                     "supportsStartDebuggingRequest": true,
                     "supportsProgressReporting": true,
-                    "supportsInvalidatedEvent": false,
+                    // kotlin-lsp sends `invalidated` either way.
+                    "supportsInvalidatedEvent": is_kotlin_lsp,
                     "supportsMemoryReferences": false,
                     "supportsArgsCanBeInterpretedByShell": false,
                 }),
@@ -1008,7 +1017,7 @@ impl DebugManager {
         *s.caps.lock() = if caps.is_object() { caps } else { json!({}) };
 
         // The Kotlin adapters ignore the resolved classpath and project runtime on launch.
-        let request = if s.adapter == kotlin::ADAPTER && s.request == "launch" {
+        let request = if kotlin::is_kotlin(&s.adapter) && s.request == "launch" {
             session::start_kotlin_debuggee(s, &mut arguments).await?;
             "attach"
         } else {
@@ -1032,7 +1041,7 @@ impl DebugManager {
                 jvm_memory::find_attached_jvm(s, port, finder).await;
             }
         }
-        if s.adapter == kotlin::ADAPTER {
+        if kotlin::is_kotlin(&s.adapter) {
             let host = arguments
                 .get("hostName")
                 .and_then(Value::as_str)
@@ -1044,7 +1053,7 @@ impl DebugManager {
                 .and_then(|p| u16::try_from(p).ok())
                 .filter(|p| *p != 0)
                 .ok_or_else(|| IdeError::invalid("Invalid Kotlin JDWP port"))?;
-            let (link, port) = ide_jdwp::JdwpLink::start(host, port, kotlin::link_options()).await?;
+            let (link, port) = ide_jdwp::JdwpLink::start(host, port, kotlin::link_options(&s.adapter)).await?;
             *s.jvm_inspector.lock() = Some(Arc::new(ide_jdwp::LinkInspector::new(link.clone())));
             jvm_memory::watch_link(s, &link);
             *s.jdwp_link.lock() = Some(link);
@@ -1381,6 +1390,8 @@ impl DebugManager {
 
     pub async fn threads(&self, s: DebugSessionId) -> IdeResult<Vec<ThreadInfo>> {
         let session = self.session(s)?;
+        // Before sending: a stop that overtakes the reply must not take the reply's ids as its own.
+        let stop = session.suspended.ticket();
         let body = session.conn.request_timeout("threads", Value::Null, REQUEST_TIMEOUT).await?;
         let threads: Vec<ThreadInfo> = body
             .get("threads")
@@ -1394,11 +1405,15 @@ impl DebugManager {
                     .collect()
             })
             .unwrap_or_default();
+        if let Some(quirks) = session.kotlin_lsp_quirks() {
+            quirks.saw_threads(stop, threads.iter().map(|t| t.id));
+        }
         Ok(threads)
     }
 
     pub async fn stack_trace(&self, s: DebugSessionId, thread_id: i64) -> IdeResult<Vec<StackFrame>> {
         let session = self.session(s)?;
+        session.check_thread(thread_id)?;
         let body = session
             .conn
             .request_timeout(
@@ -1407,11 +1422,15 @@ impl DebugManager {
                 REQUEST_TIMEOUT,
             )
             .await?;
+        let kotlin_lsp = session.kotlin_lsp_quirks().is_some();
         let frame = |f: &Value| {
             let mut frame = frame_from(f);
             if let Some(client) = frame.path.as_deref().and_then(|p| session.client_path(&p.to_string_lossy())) {
                 frame.path = Some(client.into());
             }
+            if kotlin_lsp {
+                frame.name = kotlin_lsp::frame_name(&frame.name).to_owned();
+            }
             frame
         };
         Ok(body.get("stackFrames").and_then(Value::as_array).map(|f| f.iter().map(frame).collect()).unwrap_or_default())
@@ -1523,6 +1542,10 @@ impl DebugManager {
 
     pub async fn resume(&self, s: DebugSessionId, thread_id: i64) -> IdeResult<()> {
         let session = self.session(s)?;
+        session.check_thread(thread_id)?;
+        if let Some(quirks) = session.kotlin_lsp_quirks() {
+            quirks.resume_sent();
+        }
         let ticket = session.suspended.ticket();
         let body = session.conn.request_timeout("continue", json!({ "threadId": thread_id }), REQUEST_TIMEOUT).await?;
         // DAP: a response without the flag continued every thread.
@@ -1567,8 +1590,13 @@ impl DebugManager {
             StepKind::Out => "stepOut",
         };
         let session = self.session(s)?;
+        session.check_thread(thread_id)?;
+        if let Some(quirks) = session.kotlin_lsp_quirks() {
+            quirks.step_sent();
+        }
         let ticket = session.suspended.ticket();
-        session.conn.request_timeout(command, json!({ "threadId": thread_id }), REQUEST_TIMEOUT).await?;
+        let sent = session.conn.request_timeout(command, json!({ "threadId": thread_id }), REQUEST_TIMEOUT).await;
+        step_settled(&session, sent)?;
         // A step runs its thread; other threads stopped by their own events stay stopped.
         session.suspended.resumed(ticket, thread_id, false);
         session.emit(ide_core::event::DebugEvent::Continued { thread_id, all_threads_continued: true });
@@ -1587,6 +1615,8 @@ impl DebugManager {
         force: bool,
     ) -> IdeResult<()> {
         let session = self.session(s)?;
+        // Before touching breakpoints: a refused `continue` would leave them replaced.
+        session.check_thread(thread_id)?;
         if force {
             self.suspend_breakpoints(&session, Some(&path)).await?;
         }
@@ -1661,6 +1691,7 @@ impl DebugManager {
     /// Force Step Over: `next` with every breakpoint suspended until the step ends.
     pub async fn force_step_over(&self, s: DebugSessionId, thread_id: i64) -> IdeResult<()> {
         let session = self.session(s)?;
+        session.check_thread(thread_id)?;
         self.suspend_breakpoints(&session, None).await?;
         self.step(s, thread_id, StepKind::Over).await
     }
@@ -1668,11 +1699,16 @@ impl DebugManager {
     /// Step into a specific call of the current line (Smart Step Into).
     pub async fn step_in_target(&self, s: DebugSessionId, thread_id: i64, target_id: i64) -> IdeResult<()> {
         let session = self.session(s)?;
+        session.check_thread(thread_id)?;
+        if let Some(quirks) = session.kotlin_lsp_quirks() {
+            quirks.step_sent();
+        }
         let ticket = session.suspended.ticket();
-        session
+        let sent = session
             .conn
             .request_timeout("stepIn", json!({ "threadId": thread_id, "targetId": target_id }), REQUEST_TIMEOUT)
-            .await?;
+            .await;
+        step_settled(&session, sent)?;
         session.suspended.resumed(ticket, thread_id, false);
         session.emit(ide_core::event::DebugEvent::Continued { thread_id, all_threads_continued: true });
         Ok(())

crates/ide-dap/src/session.rs

@@ -3,6 +3,7 @@
 
 use crate::adapter::AdapterSpec;
 use crate::connection::{Connection, DapError, Incoming};
+use crate::kotlin_lsp;
 use crate::{Breakpoint, BreakpointState, DataBreakpoint, DebugManager, FunctionBreakpoint, SessionOwner};
 use ide_core::event::DebugEvent;
 #[cfg(unix)]
@@ -103,6 +104,8 @@ pub(crate) struct Session {
     pub jvm_located: watch::Sender<bool>,
     pub kotlin_mirror: Mutex<Option<crate::kotlin::SourceMirror>>,
     pub jvm_memory: tokio::sync::Mutex<crate::JvmMemoryState>,
+    /// Used only by a kotlin-lsp session: see [`Session::kotlin_lsp_quirks`].
+    pub(crate) quirks: kotlin_lsp::Quirks,
 }
 
 /// Which threads of the program are suspended: each from its `stopped` event until a
@@ -252,6 +255,19 @@ impl Session {
             jvm_located: watch::channel(false).0,
             kotlin_mirror: Mutex::new(None),
             jvm_memory: tokio::sync::Mutex::default(),
+            quirks: kotlin_lsp::Quirks::default(),
+        }
+    }
+
+    pub fn kotlin_lsp_quirks(&self) -> Option<&kotlin_lsp::Quirks> {
+        (self.adapter == kotlin_lsp::ADAPTER).then_some(&self.quirks)
+    }
+
+    /// Call before sending a request for thread `id`.
+    pub fn check_thread(&self, id: i64) -> ide_core::IdeResult<()> {
+        match self.kotlin_lsp_quirks() {
+            Some(quirks) => quirks.check_thread(self.suspended.ticket(), self.suspended.get(), id),
+            None => Ok(()),
         }
     }
 
@@ -283,6 +299,11 @@ impl Session {
 
     /// A path from the adapter as the IDE knows it (undoes [`Session::adapter_path`]).
     pub fn client_path(&self, path: &str) -> Option<PathBuf> {
+        if self.adapter == kotlin_lsp::ADAPTER
+            && let Some(path) = kotlin_lsp::source_path(path)
+        {
+            return Some(path);
+        }
         if let Some(real) = self.kotlin_mirror.lock().as_ref().and_then(|m| m.client_path(Path::new(path))) {
             return Some(real);
         }
@@ -697,7 +718,11 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
         "stopped" => {
             let all = body.get("allThreadsStopped").and_then(Value::as_bool).unwrap_or(false);
             s.suspended.stopped(int("threadId"), all);
-            let reason = str_("reason").unwrap_or_else(|| "pause".into());
+            let mut reason = str_("reason").unwrap_or_else(|| "pause".into());
+            if let Some(quirks) = s.kotlin_lsp_quirks() {
+                quirks.saw_threads(s.suspended.ticket(), int("threadId"));
+                reason = quirks.stop_reason(reason);
+            }
             mgr.restore_breakpoints(s).await;
             s.emit(DebugEvent::Stopped {
                 thread_id: int("threadId").unwrap_or(0),
@@ -799,6 +824,14 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
             change_type: crate::hot_code_replace_type(body.get("changeType")),
             message: str_("message").unwrap_or_default(),
         }),
+        // Sent only by adapters told `supportsInvalidatedEvent` (kotlin-lsp).
+        "invalidated" => s.emit(DebugEvent::Invalidated {
+            areas: body
+                .get("areas")
+                .and_then(Value::as_array)
+                .map(|a| a.iter().filter_map(Value::as_str).map(str::to_owned).collect())
+                .unwrap_or_default(),
+        }),
         _ => tracing::trace!("dap: ignored event {event}"),
     }
 }

crates/ide-dap/src/tests.rs

@@ -126,8 +126,22 @@ struct Script {
     continued_after_stop: bool,
     /// Close the connection when a `pause` request arrives (the adapter dies).
     hang_up_on_pause: bool,
+    /// Close the connection at the first request after the first `stopped` event.
+    hang_up_after_stop: bool,
     /// Answer `continue` with this body and keep the program running, instead of letting it exit.
     continue_reply: Option<Value>,
+    /// Answer `continue` and stop at a breakpoint again, instead of letting the program exit.
+    stop_after_continue: bool,
+    /// The `reason` of the stop a `next` ends with (`step` when unset; kotlin-lsp says `breakpoint`).
+    step_reason: Option<&'static str>,
+    /// Refuse `next`, then stop at a breakpoint (one the program hit meanwhile).
+    refuse_next: bool,
+    /// Send `invalidated { areas: ["variables"] }` right after the first `stopped` event.
+    invalidated_after_stop: bool,
+    /// On `threads`: stop again on thread 2 first, then answer with thread 1 of the earlier stop.
+    stop_during_threads: bool,
+    /// Name of the first stack frame (`main` when unset).
+    frame_name: Option<&'static str>,
     /// Answer `initialize` only after this long (a slow adapter keeps the session connecting).
     delay_initialize: Option<Duration>,
     initialized_delay: Duration,
@@ -156,7 +170,14 @@ impl Default for Script {
             hold_set_breakpoints: 0,
             continued_after_stop: false,
             hang_up_on_pause: false,
+            hang_up_after_stop: false,
             continue_reply: None,
+            stop_after_continue: false,
+            step_reason: None,
+            refuse_next: false,
+            invalidated_after_stop: false,
+            stop_during_threads: false,
+            frame_name: None,
             delay_initialize: None,
             initialized_delay: Duration::ZERO,
             launch_delay: Duration::ZERO,
@@ -202,6 +223,7 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
     let mut seq = 1000;
     let mut pending_launch: Option<i64> = None;
     let mut held: Vec<Value> = Vec::new();
+    let mut stopped = false;
     let mut running = false;
     macro_rules! send {
         ($v:expr) => {{
@@ -222,6 +244,9 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
         if msg["type"] == "response" {
             continue;
         }
+        if script.hang_up_after_stop && stopped {
+            break;
+        }
         match msg["command"].as_str().unwrap_or_default() {
             "initialize" => {
                 if let Some(delay) = script.delay_initialize {
@@ -320,9 +345,18 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 ok!(msg, Value::Null);
                 send!(json!({"type": "event", "event": "stopped", "body": {"reason": "restart", "threadId": 1}}));
             }
+            "next" if script.refuse_next => {
+                send!(
+                    json!({"type": "response", "request_seq": msg["seq"], "command": "next", "success": false, "message": "refused"})
+                );
+                // Lets the client handle the refusal before the stop.
+                tokio::time::sleep(Duration::from_millis(50)).await;
+                send!(json!({"type": "event", "event": "stopped", "body": {"reason": "breakpoint", "threadId": 1}}));
+            }
             "next" => {
                 ok!(msg, Value::Null);
-                send!(json!({"type": "event", "event": "stopped", "body": {"reason": "step", "threadId": 1}}));
+                let reason = script.step_reason.unwrap_or("step");
+                send!(json!({"type": "event", "event": "stopped", "body": {"reason": reason, "threadId": 1}}));
             }
             "setVariable" => {
                 ok!(msg, json!({"value": format!("{}!", msg["arguments"]["value"].as_str().unwrap()), "type": "int"}))
@@ -358,6 +392,12 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 send!(
                     json!({"type": "event", "event": "stopped", "body": {"reason": "breakpoint", "threadId": 1, "allThreadsStopped": true}})
                 );
+                stopped = true;
+                if script.invalidated_after_stop {
+                    send!(
+                        json!({"type": "event", "event": "invalidated", "body": {"areas": ["variables"], "threadId": 1}})
+                    );
+                }
                 if script.continued_after_stop {
                     send!(json!({"type": "event", "event": "continued", "body": {"threadId": 1}}));
                 }
@@ -365,11 +405,19 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                     json!({"type": "event", "event": "breakpoint", "body": {"reason": "changed", "breakpoint": {"id": 1, "verified": false, "message": "moved", "line": 9, "source": {"path": script.source_path}}}})
                 );
             }
+            "threads" if script.stop_during_threads => {
+                send!(
+                    json!({"type": "event", "event": "stopped", "body": {"reason": "breakpoint", "threadId": 2, "allThreadsStopped": true}})
+                );
+                // Lets the client handle the stop before it reads the reply.
+                tokio::time::sleep(Duration::from_millis(50)).await;
+                ok!(msg, json!({"threads": [{"id": 1, "name": "\"main\"@1"}]}));
+            }
             "threads" => ok!(msg, json!({"threads": [{"id": 1, "name": "MainThread"}]})),
             "stackTrace" => ok!(
                 msg,
                 json!({"stackFrames": [
-                    {"id": 10, "name": "main", "line": 5, "column": 3, "source": {"path": script.source_path.as_deref().unwrap_or("/p/a.py")}},
+                    {"id": 10, "name": script.frame_name.unwrap_or("main"), "line": 5, "column": 3, "source": {"path": script.source_path.as_deref().unwrap_or("/p/a.py")}},
                     {"id": 11, "name": "lib", "line": 1, "column": 1, "source": {"path": "/usr/lib/x.py", "presentationHint": "deemphasize"}},
                 ]})
             ),
@@ -393,6 +441,12 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 ]})
             ),
             "continue" if script.continue_reply.is_some() => ok!(msg, script.continue_reply.clone().unwrap()),
+            "continue" if script.stop_after_continue => {
+                ok!(msg, json!({"allThreadsContinued": true}));
+                send!(
+                    json!({"type": "event", "event": "stopped", "body": {"reason": "breakpoint", "threadId": 1, "allThreadsStopped": true}})
+                );
+            }
             "continue" => {
                 ok!(msg, json!({"allThreadsContinued": true}));
                 send!(json!({"type": "event", "event": "exited", "body": {"exitCode": 3}}));
@@ -1418,6 +1472,7 @@ fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegist
         indent: None,
         ui_mode: None,
         framework_ui_modes: Vec::new(),
+        framework_files: Vec::new(),
         formatter: None,
         scratch_template: None,
         tree_sitter: None,
@@ -2041,20 +2096,20 @@ async fn stop_kills_the_program_started_by_the_reported_launcher() {
 fn delve_leftovers_are_removed_without_touching_other_files() {
     let dir = std::env::temp_dir().join(format!("openidea-delve-bin-{}", std::process::id()));
     std::fs::create_dir_all(&dir).unwrap();
-    for name in ["__debug_bin", "__debug_bin.exe", "__debug_bin.exe3323301925"] {
+    for name in ["__debug_bin", "__debug_bin833767175", "__debug_bin.exe", "__debug_bin.exe3323301925"] {
         std::fs::write(dir.join(name), b"bin").unwrap();
     }
     // Lookalikes that are not Delve's own binaries stay: sources, a future
     // in-progress build, and a directory that happens to share the name.
-    for name in ["__debug_bin.go", "__debug_bin.go.exe", "main.go"] {
+    for name in ["__debug_bin.go", "__debug_bin.go.exe", "__debug_bin12.go", "main.go"] {
         std::fs::write(dir.join(name), b"keep").unwrap();
     }
     std::fs::create_dir(dir.join("__debug_bin.dir")).unwrap();
     remove_delve_binaries(&dir);
-    for name in ["__debug_bin", "__debug_bin.exe", "__debug_bin.exe3323301925"] {
+    for name in ["__debug_bin", "__debug_bin833767175", "__debug_bin.exe", "__debug_bin.exe3323301925"] {
         assert!(!dir.join(name).exists(), "{name} should be gone");
     }
-    for name in ["__debug_bin.go", "__debug_bin.go.exe", "main.go", "__debug_bin.dir"] {
+    for name in ["__debug_bin.go", "__debug_bin.go.exe", "__debug_bin12.go", "main.go", "__debug_bin.dir"] {
         assert!(dir.join(name).exists(), "{name} should stay");
     }
     std::fs::remove_dir_all(&dir).unwrap();
@@ -2401,6 +2456,13 @@ fn kotlin_attach(project: &std::path::Path, host: &str, port: u16) -> LaunchConf
     }
 }
 
+#[test]
+fn link_options_hold_only_for_fwcd() {
+    assert!(kotlin::link_options(kotlin::ADAPTER).hold_resumes);
+    assert!(!kotlin::link_options(kotlin_lsp::ADAPTER).hold_resumes);
+    assert!(!kotlin::link_options("x").hold_resumes);
+}
+
 #[tokio::test]
 async fn kotlin_session_installs_link_inspector() {
     let h = harness(Script::default());
@@ -2472,6 +2534,229 @@ async fn closing_the_session_drops_the_link() {
     assert!(session.jvm_inspector.lock().is_none());
 }
 
+/// kotlin-lsp's debugger, reached through the language server's `debugServer` port (the fake ignores it).
+fn kotlin_lsp_attach(project: &std::path::Path) -> LaunchConfig {
+    LaunchConfig {
+        adapter: kotlin_lsp::ADAPTER.into(),
+        request: "attach".into(),
+        cwd: Some(project.to_owned().into()),
+        extra_json: Some(
+            json!({"debugServer": 4711, "hostName": "127.0.0.1", "port": 5005, "projectRoot": project}).to_string(),
+        ),
+        ..config()
+    }
+}
+
+#[tokio::test]
+async fn kotlin_lsp_initializes_as_intellij_jvm() {
+    let project = tempfile::tempdir().unwrap();
+    for (config, adapter_id, invalidated) in [
+        (kotlin_lsp_attach(project.path()), "intellij_jvm", true),
+        (kotlin_attach(project.path(), "127.0.0.1", 5005), "kotlin-debug-adapter", false),
+    ] {
+        let h = harness(Script::default());
+        let id = h.start(config).await.unwrap();
+        let init = &h.request("initialize")["arguments"];
+        assert_eq!(init["adapterID"], adapter_id);
+        assert_eq!(init["supportsInvalidatedEvent"], invalidated, "{adapter_id}");
+        h.manager.stop(id).await.unwrap();
+    }
+}
+
+#[tokio::test]
+async fn kotlin_lsp_gets_real_paths_and_its_link_holds_nothing() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let path = project.path().join("Main.kt");
+    std::fs::write(&path, "package org.example\nfun main() {}\n").unwrap();
+    h.manager.set_breakpoints(path.clone(), vec![bp(1)]).await.unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    assert_eq!(h.request("setBreakpoints")["arguments"]["source"]["path"], json!(path));
+    let sent = &h.request("attach")["arguments"];
+    assert_eq!(sent["projectRoot"], json!(project.path()));
+    assert!(sent.get("debugServer").is_none());
+    assert_eq!(sent["hostName"], "127.0.0.1");
+    let link_port = sent["port"].as_u64().unwrap();
+    assert!(link_port != 0 && link_port != 5005);
+    let session = h.manager.session(id).unwrap();
+    assert!(session.kotlin_mirror.lock().is_none());
+    assert!(session.jdwp_link.lock().is_some() && session.jvm_inspector.lock().is_some());
+    assert_eq!(session.attach_target.get(), Some(&("127.0.0.1".to_owned(), 5005)));
+    assert!(!kotlin::link_options(&session.adapter).hold_resumes);
+    h.manager.stop(id).await.unwrap();
+}
+
+#[tokio::test]
+async fn kotlin_lsp_waits_for_the_configuration_done_reply() {
+    let project = tempfile::tempdir().unwrap();
+    // fwcd never answers it (`kotlin_configures_without_configuration_done_response`).
+    let h = harness(Script { ignore_configuration_done: true, ..Default::default() });
+    let fwcd = h.start(kotlin_attach(project.path(), "127.0.0.1", 5005));
+    let id = tokio::time::timeout(Duration::from_secs(2), fwcd).await.unwrap().unwrap();
+    h.manager.stop(id).await.unwrap();
+
+    tokio::time::pause();
+    let h = harness(Script { ignore_configuration_done: true, ..Default::default() });
+    let started = tokio::time::Instant::now();
+    let err = h.start(kotlin_lsp_attach(project.path())).await.unwrap_err();
+    assert!(started.elapsed() >= REQUEST_TIMEOUT, "{:?}", started.elapsed());
+    assert!(err.message.contains("configurationDone"), "{err:?}");
+    assert!(h.manager.sessions(None).is_empty());
+}
+
+#[tokio::test]
+async fn kotlin_lsp_sessions_have_the_memory_tab() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    assert!(h.manager.capabilities(id).unwrap().jvm_memory);
+    h.manager.stop(id).await.unwrap();
+}
+
+#[tokio::test]
+async fn losing_the_kotlin_lsp_connection_ends_the_session() {
+    let h = harness(Script { hang_up_after_stop: true, ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    let session = h.manager.session(id).unwrap();
+    assert!(session.jdwp_link.lock().is_some());
+    let _ = session.conn.request_timeout("threads", Value::Null, Duration::from_secs(2)).await;
+    h.wait_event(|e| matches!(e, DebugEvent::Terminated)).await;
+    assert!(h.manager.sessions(None).is_empty());
+    assert!(session.jdwp_link.lock().is_none());
+    assert!(session.jvm_inspector.lock().is_none());
+}
+
+/// The reasons of the first `count` stops, once that many arrived.
+async fn stop_reasons(h: &Harness, count: usize) -> Vec<String> {
+    for _ in 0..200 {
+        let reasons: Vec<String> = h
+            .events
+            .lock()
+            .iter()
+            .filter_map(|e| match e {
+                IdeEvent::Debug { event: DebugEvent::Stopped { reason, .. }, .. } => Some(reason.clone()),
+                _ => None,
+            })
+            .collect();
+        if reasons.len() >= count {
+            return reasons;
+        }
+        tokio::time::sleep(Duration::from_millis(10)).await;
+    }
+    panic!("{count} stops not received; got {:?}", h.events.lock());
+}
+
+#[tokio::test]
+async fn a_step_stop_is_reported_as_a_step() {
+    let project = tempfile::tempdir().unwrap();
+    for (config, reason) in [(kotlin_lsp_attach(project.path()), "step"), (config(), "breakpoint")] {
+        let h = harness(Script { step_reason: Some("breakpoint"), ..Script::default() });
+        let id = h.start(config).await.unwrap();
+        h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+        h.manager.step(id, 1, StepKind::Over).await.unwrap();
+        assert_eq!(stop_reasons(&h, 2).await, ["breakpoint", reason]);
+        h.manager.stop(id).await.unwrap();
+    }
+}
+
+#[tokio::test]
+async fn a_breakpoint_after_continue_stays_a_breakpoint() {
+    let h = harness(Script { step_reason: Some("breakpoint"), stop_after_continue: true, ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    h.manager.step(id, 1, StepKind::Over).await.unwrap();
+    stop_reasons(&h, 2).await;
+    // The fake ends `stepIn` with no stop: the `continue` after it decides the next one.
+    h.manager.step(id, 1, StepKind::Into).await.unwrap();
+    h.manager.resume(id, 1).await.unwrap();
+    assert_eq!(stop_reasons(&h, 3).await, ["breakpoint", "step", "breakpoint"]);
+    h.manager.stop(id).await.unwrap();
+}
+
+#[tokio::test]
+async fn a_breakpoint_after_a_refused_step_stays_a_breakpoint() {
+    let h = harness(Script { refuse_next: true, ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    assert!(h.manager.step(id, 1, StepKind::Over).await.is_err());
+    assert_eq!(stop_reasons(&h, 2).await, ["breakpoint", "breakpoint"]);
+    h.manager.stop(id).await.unwrap();
+}
+
+#[tokio::test]
+async fn a_thread_from_an_earlier_stop_is_refused() {
+    let project = tempfile::tempdir().unwrap();
+    for (config, kotlin_lsp) in [(kotlin_lsp_attach(project.path()), true), (config(), false)] {
+        let h = harness(Script::default());
+        let id = h.start(config).await.unwrap();
+        h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+        assert_eq!(h.manager.threads(id).await.unwrap().len(), 1);
+        let started = tokio::time::Instant::now();
+        let stale = h.manager.stack_trace(id, 99).await;
+        let asked =
+            |command: &str| h.log.lock().iter().any(|m| m["command"] == command && m["arguments"]["threadId"] == 99);
+        if kotlin_lsp {
+            assert!(stale.is_err() && started.elapsed() < Duration::from_millis(100), "{stale:?}");
+            assert!(h.manager.step(id, 99, StepKind::Over).await.is_err());
+            assert!(h.manager.resume(id, 99).await.is_err());
+            assert!(!asked("stackTrace") && !asked("next") && !asked("continue"));
+        } else {
+            assert!(stale.is_ok() && asked("stackTrace"), "{stale:?}");
+        }
+        assert!(h.manager.stack_trace(id, 1).await.is_ok());
+        h.manager.stop(id).await.unwrap();
+    }
+}
+
+#[tokio::test]
+async fn a_threads_reply_from_before_a_stop_does_not_vouch_for_its_ids() {
+    let h = harness(Script { stop_during_threads: true, ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    let threads = h.manager.threads(id).await.unwrap();
+    // M3 maps kotlin-lsp's threads by these names.
+    assert_eq!((threads[0].id, threads[0].name.as_str()), (1, "\"main\"@1"));
+    stop_reasons(&h, 2).await;
+    assert!(h.manager.stack_trace(id, 1).await.is_err());
+    assert!(h.manager.stack_trace(id, 2).await.is_ok());
+    h.manager.stop(id).await.unwrap();
+}
+
+#[tokio::test]
+async fn kotlin_lsp_frames_get_real_paths() {
+    let project = tempfile::tempdir().unwrap();
+    let at = "at com.x.AppKt.main(App.kt:13)";
+    for (config, path, name) in [
+        (kotlin_lsp_attach(project.path()), "/p/App.kt", "com.x.AppKt.main(App.kt:13)"),
+        (java_config("launch"), "file:///p/App.kt", at),
+    ] {
+        let script = Script { source_path: Some("file:///p/App.kt".into()), frame_name: Some(at), ..Script::default() };
+        let h = harness(script);
+        let id = h.start(config).await.unwrap();
+        h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+        let frames = h.manager.stack_trace(id, 1).await.unwrap();
+        assert_eq!(frames[0].path.as_ref().map(|p| p.0.clone()), Some(PathBuf::from(path)));
+        assert_eq!(frames[0].name, name);
+        h.manager.stop(id).await.unwrap();
+    }
+}
+
+#[tokio::test]
+async fn invalidated_events_reach_the_client() {
+    let h = harness(Script { invalidated_after_stop: true, ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_lsp_attach(project.path())).await.unwrap();
+    match h.wait_event(|e| matches!(e, DebugEvent::Invalidated { .. })).await {
+        DebugEvent::Invalidated { areas } => assert_eq!(areas, ["variables"]),
+        other => panic!("{other:?}"),
+    }
+    h.manager.stop(id).await.unwrap();
+}
 #[cfg(unix)]
 #[tokio::test]
 async fn rdbg_drains_test_output_after_dap_closes_before_killing_the_process() {

crates/ide-host/src/data_dirs.rs

@@ -9,6 +9,14 @@ use std::path::{Path, PathBuf};
 /// configuration and roaming data keep following the OS.
 pub const LOCAL_DATA_ENV: &str = "OPENIDEA_LOCAL_DATA_DIR";
 
+/// A custom local-data root chosen in Settings › System Settings › Caches,
+/// stored in the configuration directory. The environment variable still wins.
+pub const OVERRIDE_FILE: &str = "local-data-dir.txt";
+
+/// A pending move of the local data to a newly chosen directory, carried out
+/// at the next start (before any project opens), like File › Invalidate Caches.
+const MIGRATION_FILE: &str = "local-data-migration.json";
+
 /// `$OPENIDEA_LOCAL_DATA_DIR/<identifier>` when set, else the OS local data directory
 /// (Tauri's `app_local_data_dir`). The identifier keeps release and per-worktree
 /// debug builds apart under one root. A set but unusable path is an error, never a
@@ -17,6 +25,203 @@ pub fn local_data_dir(identifier: &str) -> Result<PathBuf, String> {
     resolve_local(std::env::var_os(LOCAL_DATA_ENV), dirs::data_local_dir(), identifier)
 }
 
+/// The directory to actually start with: the environment override, else a valid
+/// custom directory from Settings, else the OS default. A stored but unusable
+/// custom directory is an error, never a silent fallback.
+pub fn startup_local_data_dir(identifier: &str) -> Result<PathBuf, String> {
+    startup_resolve(std::env::var_os(LOCAL_DATA_ENV), stored_override(identifier), dirs::data_local_dir(), identifier)
+}
+
+fn startup_resolve(
+    var: Option<OsString>,
+    stored: Option<PathBuf>,
+    os: Option<PathBuf>,
+    identifier: &str,
+) -> Result<PathBuf, String> {
+    if var.as_ref().is_some_and(|v| !v.is_empty()) {
+        return resolve_local(var, os, identifier);
+    }
+    let Some(root) = stored else { return resolve_local(None, os, identifier) };
+    if !root.is_absolute() {
+        return Err(format!("custom local data directory must be an absolute path: {}", root.display()));
+    }
+    resolve_root(root, identifier, "custom local data directory")
+}
+
+/// The file holding the custom local-data root, if the platform exposes its
+/// configuration directory. Both startup and Settings use this one path.
+pub fn override_path(identifier: &str) -> Option<PathBuf> {
+    dirs::config_dir().map(|dir| dir.join(identifier).join(OVERRIDE_FILE))
+}
+
+fn migration_path(identifier: &str) -> Option<PathBuf> {
+    dirs::config_dir().map(|dir| dir.join(identifier).join(MIGRATION_FILE))
+}
+
+/// The custom root stored by Settings, if any (validated when it is used).
+pub fn stored_override(identifier: &str) -> Option<PathBuf> {
+    stored_override_in(&override_path(identifier)?)
+}
+
+fn stored_override_in(path: &Path) -> Option<PathBuf> {
+    let text = fs::read_to_string(path).ok()?;
+    let trimmed = text.trim();
+    (!trimmed.is_empty()).then(|| PathBuf::from(trimmed))
+}
+
+/// The OS default local data directory (what clearing the custom directory
+/// returns to), ignoring any stored override. The environment still applies.
+pub fn default_local_data_dir(identifier: &str) -> Result<PathBuf, String> {
+    local_data_dir(identifier)
+}
+
+/// Stores (`Some`) or clears (`None`) the custom local-data root, returning the
+/// directory that takes effect after a restart. A pending custom migration to
+/// anywhere else is dropped: only the caller schedules the matching one.
+pub fn set_override(identifier: &str, root: Option<&Path>) -> Result<PathBuf, String> {
+    let Some(path) = override_path(identifier) else {
+        return Err("cannot find the configuration directory".into());
+    };
+    set_override_in(&path, &migration_path(identifier), root, identifier)
+}
+
+fn set_override_in(
+    path: &Path,
+    migration: &Option<PathBuf>,
+    root: Option<&Path>,
+    identifier: &str,
+) -> Result<PathBuf, String> {
+    if let Some(migration) = migration {
+        let _ = fs::remove_file(migration);
+    }
+    let Some(root) = root else {
+        if let Err(error) = fs::remove_file(path)
+            && error.kind() != io::ErrorKind::NotFound
+        {
+            return Err(format!("cannot clear the custom local data directory: {error}"));
+        }
+        return local_data_dir(identifier);
+    };
+    if !root.is_absolute() {
+        return Err(format!("custom local data directory must be an absolute path: {}", root.display()));
+    }
+    let dir = resolve_root(root.to_path_buf(), identifier, "custom local data directory")?;
+    if let Some(parent) = path.parent()
+        && let Err(error) = fs::create_dir_all(parent)
+    {
+        return Err(format!("cannot store the custom local data directory: {error}"));
+    }
+    if let Err(error) = fs::write(path, format!("{}\n", root.display())) {
+        return Err(format!("cannot store the custom local data directory: {error}"));
+    }
+    Ok(dir)
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+struct CustomMigration {
+    from: PathBuf,
+    to: PathBuf,
+}
+
+/// Schedules a move of the local data from `from` to `to` at the next start.
+/// Returns false when there is nothing to move. The caller restarts the IDE.
+pub fn schedule_custom_migration(identifier: &str, from: &Path, to: &Path) -> Result<bool, String> {
+    let Some(path) = migration_path(identifier) else {
+        return Err("cannot find the configuration directory".into());
+    };
+    schedule_custom_migration_in(&path, from, to)
+}
+
+fn schedule_custom_migration_in(path: &Path, from: &Path, to: &Path) -> Result<bool, String> {
+    if from == to {
+        return Ok(false);
+    }
+    if let Some(parent) = path.parent()
+        && let Err(error) = fs::create_dir_all(parent)
+    {
+        return Err(format!("cannot schedule the data move: {error}"));
+    }
+    let json = serde_json::to_vec(&CustomMigration { from: from.into(), to: to.into() })
+        .map_err(|error| format!("cannot schedule the data move: {error}"))?;
+    if let Err(error) = fs::write(path, json) {
+        return Err(format!("cannot schedule the data move: {error}"));
+    }
+    Ok(true)
+}
+
+/// Carries out a scheduled custom migration aimed at `local` (call at start-up,
+/// before projects open). Entries that appear in the meantime are never
+/// overwritten; a partially moved tree is retried at the next start.
+pub fn apply_custom_migration(identifier: &str, local: &Path) {
+    let Some(path) = migration_path(identifier) else { return };
+    apply_custom_migration_in(&path, local);
+}
+
+fn apply_custom_migration_in(path: &Path, local: &Path) {
+    let Ok(bytes) = fs::read(path) else { return };
+    let Ok(job) = serde_json::from_slice::<CustomMigration>(&bytes) else {
+        let _ = fs::remove_file(path);
+        return;
+    };
+    if job.to != local || job.from == local {
+        let _ = fs::remove_file(path);
+        return;
+    }
+    move_entries(&job.from, local, &custom_entries(&job.from));
+    let leftover = custom_entries(&job.from).into_iter().any(|entry| job.from.join(entry).exists());
+    if !leftover {
+        let _ = fs::remove_file(path);
+    }
+}
+
+/// Entries of a local-data tree that move to a newly chosen directory.
+/// Non-relocatable tool installs (virtual environments with absolute interpreter
+/// paths) stay behind and are reinstalled on demand, as in `migrate_entries`.
+fn custom_entries(root: &Path) -> Vec<PathBuf> {
+    let mut entries = local_entries(root);
+    for extra in ["logs", "agents/tools"] {
+        let entry = PathBuf::from(extra);
+        if !entries.contains(&entry) {
+            entries.push(entry);
+        }
+    }
+    entries
+}
+
+/// Moves the local-data tree from `from` to `to`, entry by entry. Same-volume
+/// entries rename at once; cross-volume copies run in the background. Targets
+/// created in the meantime are never merged into or overwritten.
+fn move_entries(from: &Path, to: &Path, entries: &[PathBuf]) {
+    if from == to {
+        return;
+    }
+    let mut copies = Vec::new();
+    for entry in entries {
+        let source = from.join(entry);
+        let target = to.join(entry);
+        match try_rename(&source, &target) {
+            Ok(true) => copies.push((source, target)),
+            Ok(false) => {}
+            Err(error) => {
+                tracing::warn!(?source, ?target, %error, "data move failed; keeping old data, using new location")
+            }
+        }
+    }
+    if !copies.is_empty() {
+        let result = std::thread::Builder::new().name("openidea-data-migration".into()).spawn(move || {
+            for (source, target) in copies {
+                tracing::info!(?source, ?target, "copying data to the new location in background");
+                if let Err(error) = copy_then_remove(&source, &target) {
+                    tracing::warn!(?source, ?target, %error, "data copy failed; keeping old data");
+                }
+            }
+        });
+        if let Err(error) = result {
+            tracing::warn!(%error, "cannot start data migration worker; keeping old data");
+        }
+    }
+}
+
 fn resolve_local(var: Option<OsString>, os: Option<PathBuf>, identifier: &str) -> Result<PathBuf, String> {
     let Some(root) = var.filter(|v| !v.is_empty()).map(PathBuf::from) else {
         return os.map(|dir| dir.join(identifier)).ok_or_else(|| "cannot find the local data directory".into());
@@ -25,10 +230,14 @@ fn resolve_local(var: Option<OsString>, os: Option<PathBuf>, identifier: &str) -
     if !root.is_absolute() {
         return Err(format!("{LOCAL_DATA_ENV} must be an absolute path: {}", root.display()));
     }
+    resolve_root(root, identifier, LOCAL_DATA_ENV)
+}
+
+fn resolve_root(root: PathBuf, identifier: &str, what: &str) -> Result<PathBuf, String> {
     let dir = root.join(identifier);
     fs::create_dir_all(&dir)
         .and_then(|()| tempfile::NamedTempFile::new_in(&dir).map(drop))
-        .map_err(|error| format!("{LOCAL_DATA_ENV}: cannot write to {}: {error}", dir.display()))?;
+        .map_err(|error| format!("{what}: cannot write to {}: {error}", dir.display()))?;
     Ok(dir)
 }
 
@@ -77,6 +286,11 @@ pub fn migrate(data: &Path, local: &Path) {
 }
 
 fn migrate_entries(data: &Path, local: &Path) {
+    move_entries(data, local, &local_entries(data));
+}
+
+/// The rebuildable entries of the legacy roaming tree that move to Local.
+fn local_entries(data: &Path) -> Vec<PathBuf> {
     let mut entries: Vec<PathBuf> = [
         "language-server-runtimes",
         "index",
@@ -118,31 +332,7 @@ fn migrate_entries(data: &Path, local: &Path) {
         Err(error) if error.kind() == io::ErrorKind::NotFound => {}
         Err(error) => tracing::warn!(%error, "cannot enumerate legacy tools; keeping old data, using Local"),
     }
-    let mut copies = Vec::new();
-    for entry in entries {
-        let source = data.join(&entry);
-        let target = data_path(data, local, &entry);
-        match try_rename(&source, &target) {
-            Ok(true) => copies.push((source, target)),
-            Ok(false) => {}
-            Err(error) => {
-                tracing::warn!(?source, ?target, %error, "data migration failed; keeping old data, using Local")
-            }
-        }
-    }
-    if !copies.is_empty() {
-        let result = std::thread::Builder::new().name("openidea-data-migration".into()).spawn(move || {
-            for (source, target) in copies {
-                tracing::info!(?source, ?target, "copying legacy data in background");
-                if let Err(error) = copy_then_remove(&source, &target) {
-                    tracing::warn!(?source, ?target, %error, "data copy failed; keeping old data, using Local");
-                }
-            }
-        });
-        if let Err(error) = result {
-            tracing::warn!(%error, "cannot start data migration worker; keeping old data, using Local");
-        }
-    }
+    entries
 }
 
 /// Returns true when a cross-volume copy is needed.
@@ -597,4 +787,108 @@ mod tests {
                 .any(|e| e.file_name().to_string_lossy().starts_with(".migration-"))
         );
     }
+
+    #[test]
+    fn custom_override_round_trips_and_validates() {
+        let tmp = tempfile::tempdir().unwrap();
+        let file = tmp.path().join("local-data-dir.txt");
+        let migration = tmp.path().join("local-data-migration.json");
+        let id = "ai.test.openidea";
+        assert_eq!(stored_override_in(&file), None);
+
+        let root = tmp.path().join("custom-root");
+        let dir = set_override_in(&file, &Some(migration.clone()), Some(&root), id).unwrap();
+        assert_eq!(dir, root.join(id));
+        assert!(dir.is_dir());
+        assert_eq!(stored_override_in(&file), Some(root.clone()));
+        assert_eq!(startup_resolve(None, stored_override_in(&file), Some(tmp.path().join("os")), id).unwrap(), dir);
+
+        // A relative root is rejected before anything is written.
+        let before = fs::read_to_string(&file).unwrap();
+        let error = set_override_in(&file, &Some(migration.clone()), Some(Path::new("relative")), id).unwrap_err();
+        assert!(error.contains("absolute"), "{error}");
+        assert_eq!(fs::read_to_string(&file).unwrap(), before);
+
+        // An unwritable root (an existing file) is rejected too.
+        let blocker = tmp.path().join("blocker");
+        fs::write(&blocker, "").unwrap();
+        let error = set_override_in(&file, &Some(migration.clone()), Some(&blocker), id).unwrap_err();
+        assert!(error.contains("cannot write"), "{error}");
+
+        // Clearing removes the file and returns the default.
+        let dir = set_override_in(&file, &Some(migration), None, id).unwrap();
+        assert!(!file.exists());
+        assert_eq!(dir, local_data_dir(id).unwrap());
+        assert_eq!(stored_override_in(&file), None);
+    }
+
+    #[test]
+    fn startup_prefers_the_environment_then_the_override() {
+        let tmp = tempfile::tempdir().unwrap();
+        let os = tmp.path().join("os");
+        let custom = tmp.path().join("custom");
+        let env = tmp.path().join("env");
+        let id = "ai.test.openidea";
+
+        let error = startup_resolve(None, Some(PathBuf::from("relative")), Some(os.clone()), id).unwrap_err();
+        assert!(error.contains("absolute"), "{error}");
+
+        // The environment wins over a stored override.
+        let dir = startup_resolve(Some(env.clone().into()), Some(custom.clone()), Some(os.clone()), id).unwrap();
+        assert_eq!(dir, env.join(id));
+
+        // Without the environment the override wins over the OS default.
+        let dir = startup_resolve(None, Some(custom.clone()), Some(os.clone()), id).unwrap();
+        assert_eq!(dir, custom.join(id));
+
+        // And without either the OS default applies.
+        let dir = startup_resolve(None, None, Some(os.clone()), id).unwrap();
+        assert_eq!(dir, os.join(id));
+    }
+
+    #[test]
+    fn custom_migration_moves_the_tree_and_clears_itself() {
+        let tmp = tempfile::tempdir().unwrap();
+        let marker = tmp.path().join("local-data-migration.json");
+        let from = tmp.path().join("old-local");
+        let to = tmp.path().join("new-local");
+        fs::create_dir_all(from.join("index/p1")).unwrap();
+        fs::write(from.join("index/p1/symbols"), "index").unwrap();
+        fs::create_dir_all(from.join("cache/p1")).unwrap();
+        fs::write(from.join("cache/p1/build"), "cache").unwrap();
+        fs::create_dir_all(from.join("tools/demo/bin")).unwrap();
+        fs::write(from.join("tools/demo/bin/demo.cmd"), "payload").unwrap();
+        fs::write(from.join("history"), "roaming stays").unwrap();
+
+        // Nothing to move: no marker is written.
+        assert!(!schedule_custom_migration_in(&marker, &from, &from).unwrap());
+        assert!(!marker.exists());
+
+        assert!(schedule_custom_migration_in(&marker, &from, &to).unwrap());
+        apply_custom_migration_in(&marker, &to);
+        assert!(!marker.exists());
+        assert_eq!(fs::read_to_string(to.join("index/p1/symbols")).unwrap(), "index");
+        assert_eq!(fs::read_to_string(to.join("cache/p1/build")).unwrap(), "cache");
+        assert!(to.join("tools/demo/bin/demo.cmd").exists());
+        assert!(!from.join("index").exists());
+        // Roaming content is not local data and stays behind.
+        assert_eq!(fs::read_to_string(from.join("history")).unwrap(), "roaming stays");
+
+        // A migration aimed elsewhere is dropped without touching anything.
+        fs::create_dir_all(from.join("lsp")).unwrap();
+        assert!(schedule_custom_migration_in(&marker, &from, &tmp.path().join("elsewhere")).unwrap());
+        apply_custom_migration_in(&marker, &to);
+        assert!(!marker.exists());
+        assert!(from.join("lsp").exists());
+        assert!(!to.join("lsp").exists());
+    }
+
+    #[test]
+    fn custom_entries_cover_logs_and_agent_tools() {
+        let tmp = tempfile::tempdir().unwrap();
+        let entries = custom_entries(tmp.path());
+        for expected in ["logs", "agents/tools", "index", "cache", "lsp", "agents/registry.json"] {
+            assert!(entries.contains(&PathBuf::from(expected)), "{entries:?}");
+        }
+    }
 }

crates/ide-host/src/ops/agent.rs

@@ -5,8 +5,9 @@ use crate::Host;
 use crate::rpc::Dispatcher;
 use ide_agent::registry::{AgentRegistry, RegistryPaths};
 use ide_agent::{
-    AgentChange, AgentCommand, AgentEntry, AgentEvent, AgentProbe, AgentPrompt, AgentProvider, AgentQueued, AgentTask,
-    ExternalSession, McpScope, McpServer, McpServerInput, NewAgentTask,
+    AcpImportOutcome, AgentAcceptOutcome, AgentChange, AgentCommand, AgentEntry, AgentEvent, AgentProbe, AgentPrompt,
+    AgentProvider, AgentQueued, AgentTask, CustomAgentInput, ExternalSession, McpScope, McpServer, McpServerInput,
+    NewAgentTask,
 };
 use ide_core::error::ErrorKind;
 use ide_core::{IdeError, IdeEvent, IdeResult, IpcPath, RequestId, SharedSink, TaskId};
@@ -44,6 +45,24 @@ pub fn set_env(
     host.project(window)?.agents.set_builtin_env(&id, env)
 }
 
+/// Saves a new custom ACP agent through its agent file.
+pub fn save_custom_agent(host: &Host, window: &str, input: CustomAgentInput) -> IdeResult<()> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.save_custom_agent(input)
+}
+
+/// Removes a custom agent's file (registry installs go through `registry_remove`).
+pub fn remove_custom_agent(host: &Host, window: &str, id: String) -> IdeResult<()> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.remove_custom_agent(&id)
+}
+
+/// Imports a JetBrains `acp.json` file's `agent_servers` entries as custom agents.
+pub fn import_acp_agents(host: &Host, window: &str, text: String) -> IdeResult<Vec<AcpImportOutcome>> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.import_acp_agents(&text)
+}
+
 /// Where ACP Registry agents are saved (`<config>/agents`, like the user's own) and installed.
 pub(crate) fn registry_paths(host: &Host) -> RegistryPaths {
     RegistryPaths::new(&host.config_dir, &host.local_data_dir)
@@ -297,6 +316,18 @@ pub async fn rollback_changes(host: &Host, window: &str, task: String, paths: Op
     host.project(window)?.agents.rollback_changes(&task, paths).await
 }
 
+/// Accept: copies a worktree task's changed files among `paths` (all without) into the
+/// local checkout, uncommitted; files the checkout changed itself are left alone and reported.
+pub async fn accept_changes(
+    host: &Host,
+    window: &str,
+    task: String,
+    paths: Option<Vec<String>>,
+) -> IdeResult<AgentAcceptOutcome> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.accept_changes(&task, paths).await
+}
+
 type McpServerMap = std::collections::BTreeMap<String, ide_core::settings::AgentMcpServer>;
 
 fn mcp_maps(host: &Host, window: &str) -> (McpServerMap, McpServerMap, Option<std::sync::Arc<crate::Project>>) {
@@ -449,6 +480,9 @@ pub(crate) fn register(d: &mut Dispatcher) {
     d.add("agent_rollback_changes", |c| async move {
         rollback_changes(&c.host, &c.window, c.arg("task")?, c.arg("paths")?).await
     });
+    d.add("agent_accept_changes", |c| async move {
+        accept_changes(&c.host, &c.window, c.arg("task")?, c.arg("paths")?).await
+    });
 }
 
 fn validate_project_root(root: &std::path::Path, requested: Option<&std::path::Path>) -> IdeResult<std::path::PathBuf> {

crates/ide-host/src/ops/debug.rs

@@ -1,3 +1,6 @@
+mod kotlin;
+#[cfg(test)]
+mod kotlin_tests;
 mod output;
 
 use crate::Host;
@@ -41,6 +44,7 @@ pub async fn debug_start(host: &Host, window: &str, config: LaunchConfig) -> Ide
             })
             .await?;
     }
+    config = kotlin::choose_kotlin_debugger(host, window, config).await?;
     if config.adapter == ide_dap::kotlin::ADAPTER {
         let data_dir = host.local_data_dir.clone();
         let runtime_root = config.cwd.clone().map(PathBuf::from).unwrap_or_default();

crates/ide-host/src/ops/debug/kotlin.rs

@@ -0,0 +1,415 @@
+//! Kotlin debugging: kotlin-lsp's debugger when the project's kotlin-lsp can serve it, else
+//! kotlin-debug-adapter with a notice saying why.
+
+use crate::Host;
+use ide_core::event::NotifyLevel;
+use ide_core::task::CancelHandle;
+use ide_core::{CancellationToken, IdeEvent, IdeResult, SharedSink, TaskId};
+use ide_dap::LaunchConfig;
+use ide_lsp::{KotlinDebugServer, KotlinDebugUnavailable};
+use parking_lot::Mutex;
+use std::collections::HashSet;
+use std::future::Future;
+use std::path::PathBuf;
+use std::time::Duration;
+
+pub(super) const KOTLIN_IMPORT_WAIT: Duration = Duration::from_secs(120);
+/// A ready kotlin-lsp answers well within this; only a longer wait shows a task.
+const TASK_DELAY: Duration = Duration::from_millis(500);
+
+// Catalogued as written (`{detail}` replaced at runtime): the text catalog test counts these
+// literals as the use of its entries.
+const TASK_TITLE: &str = "Waiting for kotlin-lsp to import the project";
+const NOTICE_TITLE: &str = "Debugging Kotlin with kotlin-debug-adapter";
+const NOT_CONFIGURED: &str = "kotlin-lsp is not the Kotlin language server of this project.";
+const NOT_INSTALLED: &str = "kotlin-lsp is not installed.";
+const NOT_STARTED: &str = "kotlin-lsp did not start: {detail}";
+const STILL_IMPORTING: &str =
+    "kotlin-lsp is still importing the project. Debug again once the import has finished to use its debugger.";
+const IMPORT_FAILED: &str = "kotlin-lsp could not import the project.";
+const FAILED: &str = "kotlin-lsp could not start its debugger: {detail}";
+
+/// `config` for kotlin-lsp's debug server on `port`; the rest of the launch stays as it is.
+pub(super) fn use_kotlin_lsp(mut config: LaunchConfig, port: u16) -> IdeResult<LaunchConfig> {
+    let mut extra = extra_object(&config)?;
+    extra.insert("debugServer".into(), port.into());
+    config.adapter = ide_dap::kotlin_lsp::ADAPTER.into();
+    config.extra_json = Some(serde_json::Value::Object(extra).to_string());
+    Ok(config)
+}
+
+/// The dedupe key of `reason` and the notice body (English, translated by the UI's catalog).
+pub(super) fn fallback_notice(reason: &KotlinDebugUnavailable) -> (&'static str, String) {
+    match reason {
+        KotlinDebugUnavailable::NotConfigured => ("notConfigured", NOT_CONFIGURED.into()),
+        KotlinDebugUnavailable::NotInstalled => ("notInstalled", NOT_INSTALLED.into()),
+        KotlinDebugUnavailable::NotStarted(detail) => ("notStarted", NOT_STARTED.replace("{detail}", detail)),
+        KotlinDebugUnavailable::StillImporting => ("stillImporting", STILL_IMPORTING.into()),
+        KotlinDebugUnavailable::ImportFailed => ("importFailed", IMPORT_FAILED.into()),
+        KotlinDebugUnavailable::Failed(detail) => ("failed", FAILED.replace("{detail}", detail)),
+    }
+}
+
+/// A kotlin-debug-adapter launch becomes a kotlin-lsp one when the project's kotlin-lsp has
+/// imported the module and started its debug server; otherwise it stays on
+/// kotlin-debug-adapter and the window is told why (once per reason).
+pub(super) async fn choose_kotlin_debugger(host: &Host, window: &str, config: LaunchConfig) -> IdeResult<LaunchConfig> {
+    if config.adapter == ide_dap::kotlin_lsp::ADAPTER {
+        require_debug_server(&config)?;
+        return Ok(config);
+    }
+    if config.adapter != ide_dap::kotlin::ADAPTER {
+        return Ok(config);
+    }
+    let Ok(project) = host.project(window) else {
+        tracing::info!(
+            "debugging Kotlin with kotlin-debug-adapter: {}",
+            fallback_notice(&KotlinDebugUnavailable::NotConfigured).1
+        );
+        return Ok(config);
+    };
+    let path = debug_path(&config).unwrap_or_else(|| project.root.clone());
+    let lsp = project.lsp.clone();
+    let chosen = wait_for_debug_server(&project.sink, |cancel| async move {
+        lsp.kotlin_debug_server(&path, KOTLIN_IMPORT_WAIT, &cancel).await
+    })
+    .await;
+    match chosen {
+        Ok(server) => use_kotlin_lsp(config, server.port),
+        Err(reason) => {
+            report_fallback(&project.kotlin_debug_notices, &project.sink, &reason);
+            Ok(config)
+        }
+    }
+}
+
+/// kotlin-lsp is only reached through the port its language server opened; without one
+/// ide-dap would try to spawn a `kotlin-lsp` adapter that does not exist.
+fn require_debug_server(config: &LaunchConfig) -> IdeResult<()> {
+    match extra_object(config)?.get("debugServer") {
+        None | Some(serde_json::Value::Null) => Err(ide_core::IdeError::invalid(
+            "A kotlin-lsp debug configuration needs \"debugServer\": the port of kotlin-lsp's debug server. \
+             Use kotlin-debug-adapter to let the IDE start it.",
+        )),
+        Some(_) => Ok(()),
+    }
+}
+
+fn extra_object(config: &LaunchConfig) -> IdeResult<serde_json::Map<String, serde_json::Value>> {
+    match config.extra_json.as_deref().map(serde_json::from_str).transpose() {
+        Ok(None) => Ok(serde_json::Map::new()),
+        Ok(Some(serde_json::Value::Object(extra))) => Ok(extra),
+        Ok(Some(other)) => Err(ide_core::IdeError::invalid(format!("launch arguments are not an object: {other}"))),
+        Err(e) => Err(ide_core::IdeError::invalid(e.to_string())),
+    }
+}
+
+/// The module to debug: the launch's `projectRoot`, else its working directory.
+fn debug_path(config: &LaunchConfig) -> Option<PathBuf> {
+    let extra: Option<serde_json::Value> = config.extra_json.as_deref().and_then(|e| serde_json::from_str(e).ok());
+    extra
+        .as_ref()
+        .and_then(|e| e.get("projectRoot")?.as_str())
+        .filter(|root| !root.is_empty())
+        .map(PathBuf::from)
+        .or_else(|| config.cwd.as_deref().map(PathBuf::from))
+}
+
+/// Runs `debug_server` with a token the user can cancel; a wait longer than [`TASK_DELAY`]
+/// shows as a cancellable task, which ends however the wait does (also when dropped).
+async fn wait_for_debug_server<F, Fut>(
+    sink: &SharedSink,
+    debug_server: F,
+) -> Result<KotlinDebugServer, KotlinDebugUnavailable>
+where
+    F: FnOnce(CancellationToken) -> Fut,
+    Fut: Future<Output = Result<KotlinDebugServer, KotlinDebugUnavailable>>,
+{
+    let cancel = CancellationToken::new();
+    let id = TaskId::next();
+    let handle = ide_core::task::on_cancel(id, {
+        let cancel = cancel.clone();
+        move || cancel.cancel()
+    });
+    let wait = debug_server(cancel);
+    tokio::pin!(wait);
+    if let Ok(answer) = tokio::time::timeout(TASK_DELAY, &mut wait).await {
+        return answer;
+    }
+    let _task = WaitTask::start(sink.clone(), id, handle);
+    wait.await
+}
+
+/// The visible import wait; dropping it ends the task.
+struct WaitTask {
+    sink: SharedSink,
+    id: TaskId,
+    _cancel: CancelHandle,
+}
+
+impl WaitTask {
+    fn start(sink: SharedSink, id: TaskId, cancel: CancelHandle) -> Self {
+        let task = Self { sink, id, _cancel: cancel };
+        task.emit(false);
+        task
+    }
+
+    fn emit(&self, done: bool) {
+        self.sink.emit(IdeEvent::Task {
+            id: self.id,
+            title: TASK_TITLE.into(),
+            message: None,
+            fraction: None,
+            done,
+            cancellable: !done,
+        });
+    }
+}
+
+impl Drop for WaitTask {
+    fn drop(&mut self) {
+        self.emit(true);
+    }
+}
+
+/// Logs every fallback; notifies the window once per reason.
+fn report_fallback(notices: &Mutex<HashSet<&'static str>>, sink: &SharedSink, reason: &KotlinDebugUnavailable) {
+    let (key, body) = fallback_notice(reason);
+    tracing::info!("debugging Kotlin with kotlin-debug-adapter: {body}");
+    if notices.lock().insert(key) {
+        sink.emit(IdeEvent::Notify { level: NotifyLevel::Info, title: NOTICE_TITLE.into(), body: Some(body) });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::path::Path;
+    use std::sync::Arc;
+
+    fn launch(adapter: &str, extra: serde_json::Value) -> LaunchConfig {
+        LaunchConfig {
+            name: "AppKt".into(),
+            adapter: adapter.into(),
+            request: "launch".into(),
+            program: None,
+            args: vec![],
+            cwd: Some("/cwd".into()),
+            env: Default::default(),
+            extra_json: Some(extra.to_string()),
+        }
+    }
+
+    fn extra(config: &LaunchConfig) -> serde_json::Value {
+        serde_json::from_str(config.extra_json.as_deref().unwrap()).unwrap()
+    }
+
+    fn reasons() -> Vec<KotlinDebugUnavailable> {
+        vec![
+            KotlinDebugUnavailable::NotConfigured,
+            KotlinDebugUnavailable::NotInstalled,
+            KotlinDebugUnavailable::NotStarted("needs JDK 21".into()),
+            KotlinDebugUnavailable::StillImporting,
+            KotlinDebugUnavailable::ImportFailed,
+            KotlinDebugUnavailable::Failed("boom".into()),
+        ]
+    }
+
+    fn recording_sink() -> (SharedSink, Arc<Mutex<Vec<IdeEvent>>>) {
+        let events = Arc::new(Mutex::new(Vec::new()));
+        let recorded = events.clone();
+        (Arc::new(move |event| recorded.lock().push(event)), events)
+    }
+
+    /// `(done, cancellable)` of each task event, with the task id.
+    fn tasks(events: &Mutex<Vec<IdeEvent>>) -> Vec<(ide_core::TaskId, String, bool, bool)> {
+        events
+            .lock()
+            .iter()
+            .filter_map(|e| match e {
+                IdeEvent::Task { id, title, done, cancellable, .. } => Some((*id, title.clone(), *done, *cancellable)),
+                _ => None,
+            })
+            .collect()
+    }
+
+    fn server() -> KotlinDebugServer {
+        KotlinDebugServer { port: 4711, root: PathBuf::from("/p") }
+    }
+
+    #[test]
+    fn kotlin_lsp_takes_the_debug_server_port() {
+        let config = launch(ide_dap::kotlin::ADAPTER, serde_json::json!({"mainClass": "a.AppKt", "projectRoot": "/p"}));
+        let c = use_kotlin_lsp(config, 4711).unwrap();
+        assert_eq!(c.adapter, ide_dap::kotlin_lsp::ADAPTER);
+        let args = extra(&c);
+        assert_eq!(args["debugServer"], 4711);
+        assert_eq!(args["mainClass"], "a.AppKt");
+        assert_eq!(args["projectRoot"], "/p");
+        assert!(args.get("__adapterJavaHome").is_none());
+        assert_eq!(
+            (c.name.as_str(), c.request.as_str(), c.cwd.as_deref()),
+            ("AppKt", "launch", Some(Path::new("/cwd")))
+        );
+        let mut bare = launch(ide_dap::kotlin::ADAPTER, serde_json::json!({}));
+        bare.extra_json = None;
+        assert_eq!(extra(&use_kotlin_lsp(bare, 4711).unwrap())["debugServer"], 4711);
+    }
+
+    #[test]
+    fn every_fallback_reason_has_a_catalogued_text() {
+        let catalogs: [(&str, serde_json::Value); 2] = [
+            ("en", serde_json::from_str(include_str!("../../../../../src/platform/locales/text/en.json")).unwrap()),
+            ("zh", serde_json::from_str(include_str!("../../../../../src/platform/locales/text/zh.json")).unwrap()),
+        ];
+        let templates = [NOT_CONFIGURED, NOT_INSTALLED, NOT_STARTED, STILL_IMPORTING, IMPORT_FAILED, FAILED];
+        for reason in reasons() {
+            let (_, body) = fallback_notice(&reason);
+            let detail = match &reason {
+                KotlinDebugUnavailable::NotStarted(d) | KotlinDebugUnavailable::Failed(d) => d.as_str(),
+                _ => "",
+            };
+            assert!(
+                templates.iter().any(|t| t.replace("{detail}", detail) == body),
+                "{reason:?}: {body:?} is not built from a catalogued template"
+            );
+        }
+        for text in templates.iter().chain([&NOTICE_TITLE, &TASK_TITLE]) {
+            for (locale, catalog) in &catalogs {
+                let translated = catalog[*text].as_str().unwrap_or_else(|| panic!("{locale}.json lacks {text:?}"));
+                if *locale == "zh" {
+                    assert_ne!(translated, *text, "zh.json leaves {text:?} untranslated");
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn fallback_reasons_have_distinct_keys() {
+        let keys: HashSet<_> = reasons().iter().map(|r| fallback_notice(r).0).collect();
+        assert_eq!(keys.len(), reasons().len());
+        // The detail does not make another reason.
+        assert_eq!(
+            fallback_notice(&KotlinDebugUnavailable::Failed("a".into())).0,
+            fallback_notice(&KotlinDebugUnavailable::Failed("b".into())).0
+        );
+    }
+
+    #[test]
+    fn a_kotlin_lsp_config_without_a_debug_server_is_refused() {
+        let refused = require_debug_server(&launch(ide_dap::kotlin_lsp::ADAPTER, serde_json::json!({}))).unwrap_err();
+        assert_eq!(refused.kind, ide_core::error::ErrorKind::InvalidInput);
+        assert!(refused.message.contains("debugServer"), "{}", refused.message);
+        let mut bare = launch(ide_dap::kotlin_lsp::ADAPTER, serde_json::json!({}));
+        bare.extra_json = None;
+        assert!(require_debug_server(&bare).is_err());
+        assert!(
+            require_debug_server(&launch(ide_dap::kotlin_lsp::ADAPTER, serde_json::json!({"debugServer": null})))
+                .is_err()
+        );
+        for port in [serde_json::json!(4711), serde_json::json!("10.0.0.5:4711")] {
+            require_debug_server(&launch(ide_dap::kotlin_lsp::ADAPTER, serde_json::json!({"debugServer": port})))
+                .unwrap();
+        }
+    }
+
+    #[test]
+    fn the_module_is_the_project_root_else_the_working_directory() {
+        let with_root = launch(ide_dap::kotlin::ADAPTER, serde_json::json!({"projectRoot": "/p/app"}));
+        assert_eq!(debug_path(&with_root), Some(PathBuf::from("/p/app")));
+        assert_eq!(debug_path(&launch(ide_dap::kotlin::ADAPTER, serde_json::json!({}))), Some(PathBuf::from("/cwd")));
+        let mut neither = launch(ide_dap::kotlin::ADAPTER, serde_json::json!({}));
+        neither.cwd = None;
+        assert_eq!(debug_path(&neither), None);
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn a_quick_answer_shows_no_task() {
+        let (sink, events) = recording_sink();
+        assert_eq!(wait_for_debug_server(&sink, |_| async { Ok(server()) }).await, Ok(server()));
+        assert!(events.lock().is_empty());
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn a_longer_wait_shows_a_task_that_ends_on_every_outcome() {
+        for outcome in [Ok(server()), Err(KotlinDebugUnavailable::ImportFailed)] {
+            let (sink, events) = recording_sink();
+            let answer = outcome.clone();
+            let result = wait_for_debug_server(&sink, |_| async move {
+                tokio::time::sleep(Duration::from_secs(5)).await;
+                answer
+            })
+            .await;
+            assert_eq!(result, outcome);
+            let tasks = tasks(&events);
+            assert_eq!(tasks.len(), 2, "{tasks:?}");
+            assert_eq!(tasks[0].0, tasks[1].0);
+            assert_eq!(tasks[0].1, TASK_TITLE);
+            assert_eq!((tasks[0].2, tasks[0].3), (false, true));
+            assert_eq!((tasks[1].2, tasks[1].3), (true, false));
+        }
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn cancelling_the_task_stops_the_wait() {
+        let (sink, events) = recording_sink();
+        let wait = tokio::spawn(async move {
+            wait_for_debug_server(&sink, |cancel| async move {
+                cancel.cancelled().await;
+                Err(KotlinDebugUnavailable::StillImporting)
+            })
+            .await
+        });
+        tokio::time::sleep(Duration::from_secs(1)).await;
+        let id = tasks(&events)[0].0;
+        assert!(ide_core::task::cancel(id));
+        assert_eq!(wait.await.unwrap(), Err(KotlinDebugUnavailable::StillImporting));
+        assert_eq!(tasks(&events).last().map(|t| t.2), Some(true));
+        assert!(!ide_core::task::cancel(id), "an ended wait is no longer cancellable");
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn a_dropped_wait_ends_its_task() {
+        let (sink, events) = recording_sink();
+        let wait = tokio::spawn(async move {
+            wait_for_debug_server(&sink, |_| std::future::pending::<Result<KotlinDebugServer, _>>()).await
+        });
+        tokio::time::sleep(Duration::from_secs(1)).await;
+        wait.abort();
+        let _ = wait.await;
+        assert_eq!(tasks(&events).iter().map(|t| t.2).collect::<Vec<_>>(), [false, true]);
+    }
+
+    #[test]
+    fn the_notice_shows_once_per_reason() {
+        let (sink, events) = recording_sink();
+        let notices = Mutex::new(HashSet::new());
+        for reason in [
+            KotlinDebugUnavailable::StillImporting,
+            KotlinDebugUnavailable::StillImporting,
+            KotlinDebugUnavailable::NotStarted("needs JDK 21".into()),
+            KotlinDebugUnavailable::NotStarted("crashed".into()),
+        ] {
+            report_fallback(&notices, &sink, &reason);
+        }
+        let notes: Vec<_> = events
+            .lock()
+            .iter()
+            .map(|e| match e {
+                IdeEvent::Notify { level, title, body } => (*level, title.clone(), body.clone()),
+                other => panic!("{other:?}"),
+            })
+            .collect();
+        assert_eq!(
+            notes,
+            [
+                (NotifyLevel::Info, NOTICE_TITLE.to_string(), Some(STILL_IMPORTING.to_string())),
+                (
+                    NotifyLevel::Info,
+                    NOTICE_TITLE.to_string(),
+                    Some("kotlin-lsp did not start: needs JDK 21".to_string())
+                ),
+            ]
+        );
+    }
+}

crates/ide-host/src/ops/debug/kotlin_tests.rs

@@ -0,0 +1,123 @@
+//! Kotlin's debugger choice through a real `Host` and project: the fallback notice and the
+//! refusal of a kotlin-lsp configuration without its debug server.
+
+use super::*;
+use crate::HostConfig;
+use ide_core::IdeEvent;
+use ide_core::event::NotifyLevel;
+use ide_lsp::KotlinDebugUnavailable;
+use ide_workspace::SettingsScope;
+use parking_lot::Mutex;
+use std::sync::Arc;
+
+const NOTICE_TITLE: &str = "Debugging Kotlin with kotlin-debug-adapter";
+
+struct Fixture {
+    host: Host,
+    root: PathBuf,
+    events: Arc<Mutex<Vec<IdeEvent>>>,
+    _temp: tempfile::TempDir,
+}
+
+impl Fixture {
+    /// A trusted Gradle project opened with these global settings; kotlin-debug-adapter is a
+    /// missing executable, so a session fails right after the debugger is chosen.
+    async fn new(settings: &[(&str, serde_json::Value)]) -> Self {
+        let temp = tempfile::tempdir().unwrap();
+        let base = dunce::canonicalize(temp.path()).unwrap();
+        let root = base.join("project");
+        std::fs::create_dir_all(&root).unwrap();
+        std::fs::write(root.join("settings.gradle.kts"), "rootProject.name = \"app\"\n").unwrap();
+        let events = Arc::new(Mutex::new(Vec::new()));
+        let captured = events.clone();
+        let host = Host::new(HostConfig {
+            config_dir: base.join("config"),
+            data_dir: base.join("data"),
+            local_data_dir: base.join("data"),
+            languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+            syntax: Arc::default(),
+            sink_for: Box::new(move |_| {
+                let events = captured.clone();
+                Arc::new(move |event| events.lock().push(event))
+            }),
+            owner: |w| w,
+            runtime: tokio::runtime::Handle::current(),
+            project_environment: false,
+        });
+        let missing = base.join("missing").join("kotlin-debug-adapter");
+        host.global_settings
+            .set(SettingsScope::Global, "tools", serde_json::json!({"kotlin-debug-adapter": {"path": missing}}))
+            .unwrap();
+        for (key, value) in settings {
+            host.global_settings.set(SettingsScope::Global, key, value.clone()).unwrap();
+        }
+        host.open_project("main", &root).unwrap();
+        host.set_project_trust(&root, true, false).await.unwrap();
+        Self { host, root, events, _temp: temp }
+    }
+
+    fn launch(&self, adapter: &str, extra: serde_json::Value) -> LaunchConfig {
+        LaunchConfig {
+            name: "AppKt".into(),
+            adapter: adapter.into(),
+            request: "launch".into(),
+            program: None,
+            args: vec![],
+            cwd: Some(self.root.clone().into()),
+            env: Default::default(),
+            extra_json: Some(extra.to_string()),
+        }
+    }
+
+    fn kotlin_launch(&self) -> LaunchConfig {
+        let extra = serde_json::json!({"mainClass": "com.example.AppKt", "projectRoot": self.root});
+        self.launch(ide_dap::kotlin::ADAPTER, extra)
+    }
+
+    /// `(level, body)` of each fallback notice.
+    fn notices(&self) -> Vec<(NotifyLevel, Option<String>)> {
+        self.events
+            .lock()
+            .iter()
+            .filter_map(|e| match e {
+                IdeEvent::Notify { level, title, body } if title == NOTICE_TITLE => Some((*level, body.clone())),
+                _ => None,
+            })
+            .collect()
+    }
+}
+
+/// Two Debugs, each failing only at kotlin-debug-adapter's missing executable.
+async fn debug_twice(f: &Fixture) {
+    for _ in 0..2 {
+        let error = debug_start(&f.host, "main", f.kotlin_launch()).await.unwrap_err();
+        assert!(!error.message.contains("Restricted Mode"), "{}", error.message);
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn kotlin_lsp_turned_off_gives_one_notice_over_two_debugs() {
+    let f = Fixture::new(&[("languageServers", serde_json::json!({"kotlin-lsp": {"enabled": false}}))]).await;
+    debug_twice(&f).await;
+    let (_, body) = kotlin::fallback_notice(&KotlinDebugUnavailable::NotConfigured);
+    assert_eq!(f.notices(), [(NotifyLevel::Info, Some(body))]);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn a_missing_kotlin_lsp_gives_one_notice_over_two_debugs() {
+    let missing = serde_json::json!({"kotlin-lsp": {"command": "/nonexistent/kotlin-lsp"}});
+    let f = Fixture::new(&[("languageServers", missing)]).await;
+    debug_twice(&f).await;
+    let (_, body) = kotlin::fallback_notice(&KotlinDebugUnavailable::NotInstalled);
+    assert_eq!(f.notices(), [(NotifyLevel::Info, Some(body))]);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn a_kotlin_lsp_config_without_its_debug_server_is_refused() {
+    let f = Fixture::new(&[]).await;
+    let config = f.launch(ide_dap::kotlin_lsp::ADAPTER, serde_json::json!({"mainClass": "com.example.AppKt"}));
+    let refused = debug_start(&f.host, "main", config).await.unwrap_err();
+    assert_eq!(refused.kind, ide_core::error::ErrorKind::InvalidInput);
+    assert!(refused.message.contains("debugServer"), "{}", refused.message);
+    assert!(f.notices().is_empty());
+}

crates/ide-host/src/ops/deploy.rs

@@ -169,6 +169,25 @@ pub async fn remote_rename(state: &Host, connection: FsConnection, from: String,
     state.remote.remote_rename(&connection, &from, &to).await
 }
 
+/// Remote Host › Download to…: remote files and folders into a local folder, each under its
+/// own name.
+pub async fn remote_download_into(
+    window: &str,
+    state: &Host,
+    connection: FsConnection,
+    paths: Vec<String>,
+    target: IpcPath,
+    request: RequestId,
+) -> IdeResult<TransferReport> {
+    let project = state.project(window)?;
+    let token = state.begin_request(request);
+    let (mut report, done) = progress(project.sink.clone(), "Downloading", token.clone());
+    let r = state.remote.download_into(&connection, &paths, &target, &token, &mut report).await;
+    done();
+    state.end_request(request);
+    r
+}
+
 pub async fn deploy_test_connection(state: &Host, connection: FsConnection, path: String) -> IdeResult<()> {
     state.remote.test_connection(&connection, &path).await
 }
@@ -197,6 +216,17 @@ pub(crate) fn register(d: &mut crate::rpc::Dispatcher) {
     d.add("remote_of", |c| async move { Ok(remote_of(&c.host, c.arg("path")?)) });
     d.add("remote_delete", |c| async move { remote_delete(&c.host, c.arg("connection")?, c.arg("path")?).await });
     d.add("remote_mkdir", |c| async move { remote_mkdir(&c.host, c.arg("connection")?, c.arg("path")?).await });
+    d.add("remote_download_into", |c| async move {
+        remote_download_into(
+            &c.window,
+            &c.host,
+            c.arg("connection")?,
+            c.arg("paths")?,
+            c.arg("target")?,
+            c.arg("request")?,
+        )
+        .await
+    });
     d.add("remote_rename", |c| async move {
         remote_rename(&c.host, c.arg("connection")?, c.arg("from")?, c.arg("to")?).await
     });

crates/ide-host/src/ops/doc/commands.rs

@@ -19,7 +19,17 @@ pub async fn blocking<T: Send + 'static>(f: impl FnOnce() -> IdeResult<T> + Send
 pub async fn doc_open_virtual(host: &Host, window: &str, uri: String) -> IdeResult<DocumentInfo> {
     let project = host.project(window)?;
     let vd = crate::ops::lsp::lsp_virtual_document(host, window, uri).await?;
-    blocking(move || project.documents.open_virtual(&vd.uri, vd.language_id, &vd.text)).await
+    blocking(move || {
+        project.documents.open_virtual(
+            &vd.uri,
+            vd.language_id,
+            &vd.text,
+            &vd.encoding,
+            vd.has_bom,
+            vd.can_reload_encoding,
+        )
+    })
+    .await
 }
 
 /// The CodeMirror mode `path` gets when opened (`DocumentInfo::ui_mode`),
@@ -30,6 +40,8 @@ pub async fn doc_ui_mode(host: &Host, window: &str, path: PathBuf) -> IdeResult<
 }
 
 /// "Reload with Encoding" (`reload`) or "Convert to Encoding"; returns the new encoding and BOM state.
+/// Virtual documents re-read their origin (archive, language server, Git blob)
+/// instead of a disk file; converting them would write to it, so it stays refused.
 pub async fn doc_set_encoding(
     host: &Host,
     window: &str,
@@ -38,6 +50,14 @@ pub async fn doc_set_encoding(
     reload: bool,
 ) -> IdeResult<DocumentEncoding> {
     let project = host.project(window)?;
+    if reload && let Some(uri) = project.documents.virtual_uri(doc)? {
+        let vd = if uri.starts_with("git-revision:") {
+            crate::ops::vcs::revision_virtual_document(host, window, &uri, Some(&encoding)).await?
+        } else {
+            project.lsp.reload_virtual(&uri, &encoding).await?
+        };
+        return host.blocking(move || project.documents.replace_virtual(doc, &vd.text, &vd.encoding, vd.has_bom)).await;
+    }
     host.blocking(move || project.documents.set_encoding(doc, &encoding, reload)).await
 }
 

crates/ide-host/src/ops/doc/tests.rs

@@ -176,8 +176,11 @@ async fn binary_and_virtual_documents_are_skipped() {
     std::fs::write(&path, b"\0\0binary payload").unwrap();
     let binary = f.open(&path).await;
     assert!(binary.read_only);
-    let virtual_doc =
-        f.project.documents.open_virtual("test://virtual", ide_core::LanguageId::plain_text(), "virtual").unwrap();
+    let virtual_doc = f
+        .project
+        .documents
+        .open_virtual("test://virtual", ide_core::LanguageId::plain_text(), "virtual", "utf-8", false, false)
+        .unwrap();
     std::fs::write(&path, "now ordinary text").unwrap();
     f.events.lock().clear();
     f.sync().await;

crates/ide-host/src/ops/lsp.rs

@@ -544,7 +544,7 @@ pub async fn lsp_goto_implementation(
 /// classes and disk class files. Cached per project.
 pub async fn lsp_virtual_document(host: &Host, window: &str, uri: String) -> IdeResult<VirtualDocument> {
     if uri.starts_with("git-revision:") {
-        return crate::ops::vcs::revision_virtual_document(host, window, &uri).await;
+        return crate::ops::vcs::revision_virtual_document(host, window, &uri, None).await;
     }
     host.project(window)?.lsp.virtual_document(&uri).await
 }

crates/ide-host/src/ops/run/commands.rs

@@ -231,8 +231,16 @@ pub async fn run_tomcat_build(host: &Host, window: &str, config: RunConfig) -> I
             .ok_or_else(|| IdeError::invalid("Choose a WAR artifact"))?;
         let base = ide_run::tomcat::effective_base_dir(&project.root, &project.cache_dir, &config)?;
         // "Build before launch" is skipped when the built WAR is already newer than the
-        // module's sources, so a repeated run does not rebuild (IDEA's up-to-date check).
-        if ide_run::tomcat::artifact_is_current(&project.root, &base, &config) {
+        // sources of every module in the build, so a repeated run does not rebuild (IDEA's
+        // up-to-date check) but a change in a dependency module does.
+        let modules: Vec<std::path::PathBuf> = model
+            .maven
+            .iter()
+            .flat_map(|m| m.projects.iter().map(|p| p.dir.as_str()))
+            .chain(model.gradle.iter().flat_map(|g| g.projects.iter().map(|p| p.dir.as_str())))
+            .map(std::path::PathBuf::from)
+            .collect();
+        if ide_run::tomcat::artifact_is_current(&project.root, &base, &config, &modules) {
             return Ok(None);
         }
         let mut plan = ide_build::web::build(&project.root, &model, id, &base)?;

crates/ide-host/src/ops/vcs/commands.rs

@@ -20,10 +20,13 @@ struct LogAccess {
 }
 
 /// Immutable Git objects exposed through the editor's ordinary read-only VFS.
+/// `encoding` re-decodes the blob with it ("Reload with Encoding") instead of
+/// the project's detection.
 pub async fn revision_virtual_document(
     host: &Host,
     window: &str,
     uri: &str,
+    encoding: Option<&str>,
 ) -> IdeResult<ide_lsp::types::VirtualDocument> {
     #[derive(Deserialize)]
     struct Target {
@@ -47,7 +50,7 @@ pub async fn revision_virtual_document(
         .collect::<IdeResult<Vec<_>>>()?;
     let target: Target = serde_json::from_slice(&bytes).map_err(|e| ide_core::IdeError::invalid(e.to_string()))?;
     let path = target.repo.join(&target.path);
-    let text = vcs_file_at(host, window, path, Some(target.revision.clone()))
+    let (text, charset, has_bom) = revision_text(host, window, &path, &target.revision, encoding)
         .await?
         .ok_or_else(|| ide_core::IdeError::not_found("file is absent at this revision"))?;
     Ok(ide_lsp::types::VirtualDocument {
@@ -57,8 +60,63 @@ pub async fn revision_virtual_document(
         title: target.path.file_name().unwrap_or_default().to_string_lossy().into_owned(),
         description: Some(format!("{} · {}", target.repo.display(), target.revision)),
         decompiled: false,
+        encoding: charset.name().to_ascii_lowercase(),
+        has_bom,
+        can_reload_encoding: true,
     })
 }
+
+/// Revision text with the charset it was decoded with and whether a matching
+/// BOM was stripped; `None` when the file is absent at the revision.
+async fn revision_text(
+    host: &Host,
+    window: &str,
+    path: &Path,
+    rev: &str,
+    encoding: Option<&str>,
+) -> IdeResult<Option<(String, &'static encoding_rs::Encoding, bool)>> {
+    let project = host.project(window).ok();
+    let external = host.external_logs.read().get(host.owner_window(window)).and_then(|rs| {
+        rs.iter().filter(|r| path.starts_with(r.root())).max_by_key(|r| r.root().components().count()).cloned()
+    });
+    let (path, rev, encoding) = (path.to_path_buf(), rev.to_owned(), encoding.map(str::to_owned));
+    blocking(move || {
+        fn with_repo<T>(
+            project: &Option<std::sync::Arc<Project>>,
+            external: &Option<std::sync::Arc<ide_vcs::Repo>>,
+            path: &Path,
+            f: impl FnOnce(&ide_vcs::Repo) -> IdeResult<T>,
+        ) -> IdeResult<T> {
+            match project {
+                Some(project) => project.with_log_repo_of(path, f),
+                None => f(external
+                    .as_ref()
+                    .ok_or_else(|| ide_core::IdeError::unavailable("external Git log is not open"))?),
+            }
+        }
+        let (text_encoding, charset) = match &encoding {
+            Some(label) => {
+                let charset = encoding_rs::Encoding::for_label(label.trim().as_bytes())
+                    .ok_or_else(|| ide_core::IdeError::invalid(format!("unknown encoding {label:?}")))?;
+                (ide_vcs::TextEncoding::from(charset), charset)
+            }
+            None => match &project {
+                Some(project) => {
+                    let text_encoding = project.vcs_encoding(&path, Some(&rev))?;
+                    (text_encoding, text_encoding.charset)
+                }
+                None => (ide_vcs::TextEncoding::from(encoding_rs::UTF_8), encoding_rs::UTF_8),
+            },
+        };
+        let bytes = with_repo(&project, &external, &path, |r| r.file_bytes_at(&path, Some(&rev)))?;
+        let Some(bytes) = bytes else { return Ok(None) };
+        let has_bom = encoding_rs::Encoding::for_bom(&bytes).is_some_and(|(enc, _)| enc == charset);
+        let text =
+            with_repo(&project, &external, &path, |r| r.file_at(&path, Some(&rev), text_encoding))?.unwrap_or_default();
+        Ok(Some((text, charset, has_bom)))
+    })
+    .await
+}
 impl LogAccess {
     fn new(host: &Host, window: &str, at: Option<&Path>) -> Self {
         let project = host.project(window).ok();

crates/ide-host/src/plugins/api.rs

@@ -896,6 +896,13 @@ impl Shared {
         self.prompts_blocked.lock().remove(plugin);
     }
 
+    /// A window other than `client` where `plugin` waits for the user's answer (a prompt or a
+    /// Commit request). The plugin runs one call at a time, so anything else asked of it waits
+    /// behind that answer.
+    pub fn waiting_elsewhere(&self, plugin: &str, client: &str) -> Option<String> {
+        self.prompts.lock().values().find(|p| p.plugin == plugin && p.client != client).map(|p| p.client.clone())
+    }
+
     /// The user answered (`Some`) or dismissed (`None`) a prompt.
     pub fn answer_prompt(&self, id: u64, answer: Option<Vec<String>>) -> bool {
         let mut prompts = self.prompts.lock();

crates/ide-host/src/plugins/mod.rs

@@ -1381,6 +1381,17 @@ impl PluginHost {
         invocation: Invocation,
         cancel: Option<&ide_core::CancellationToken>,
     ) -> IdeResult<Option<String>> {
+        // Queued behind a prompt open in another window, the command would sit there with no
+        // sign of life until that prompt is answered: point the user at it instead.
+        if let Some(client) = invocation.client.as_deref()
+            && let Some(waiting) = self.shared.waiting_elsewhere(id, client)
+        {
+            self.sink.emit(Some(&waiting), PluginEvent::PromptWaiting { plugin_id: id.to_owned() });
+            let name = self.get(id).map(|p| p.manifest().name.clone()).unwrap_or_else(|_| id.to_owned());
+            return Err(IdeError::invalid(format!(
+                "{name} is waiting for your answer in another window. Answer or close it there, then try again."
+            )));
+        }
         let (cmd, arg) = (command.to_owned(), arg.map(str::to_owned));
         self.code_call_cancellable(id, invocation, "running the command", cancel, move |rt, inv| {
             rt.run_command(&cmd, arg.as_deref(), inv)

crates/ide-host/src/plugins/navigation.rs

@@ -121,9 +121,14 @@ pub(crate) struct NavigationIndex {
 fn contains(range: Range, pos: Pos) -> bool {
     (range.start.line, range.start.col) <= (pos.line, pos.col) && (pos.line, pos.col) < (range.end.line, range.end.col)
 }
+/// Inside the document, start not after end. An empty range marks a position (a template file's
+/// definition at its start, say): navigation lands there, but it has no text to rename.
 fn valid_range(lines: &[usize], range: Range) -> bool {
     let pos = |p: Pos| lines.get(p.line as usize).is_some_and(|&length| p.col as usize <= length);
-    pos(range.start) && pos(range.end) && (range.start.line, range.start.col) < (range.end.line, range.end.col)
+    pos(range.start) && pos(range.end) && (range.start.line, range.start.col) <= (range.end.line, range.end.col)
+}
+fn is_empty(range: Range) -> bool {
+    (range.start.line, range.start.col) == (range.end.line, range.end.col)
 }
 
 impl PluginHost {
@@ -280,12 +285,20 @@ impl PluginHost {
                     .chain(&edges.references)
                     .any(|a| a.key.is_empty() || a.key.len() > 1024 || !valid_range(&lines, a.range))
             {
-                return Err(IdeError::invalid("invalid navigation anchors"));
+                return Err(IdeError::invalid(format!(
+                    "{}: invalid navigation anchors in {}",
+                    plugin.id(),
+                    path.display()
+                )));
             }
             if edges.markers.len() > MAX_EDGES
                 || edges.markers.iter().any(|a| a.key.is_empty() || a.key.len() > 1024 || !valid_range(&lines, a.range))
             {
-                return Err(IdeError::invalid("invalid navigation markers"));
+                return Err(IdeError::invalid(format!(
+                    "{}: invalid navigation markers in {}",
+                    plugin.id(),
+                    path.display()
+                )));
             }
             let mut index = self.navigation.lock();
             if index.epochs.get(root).copied() != generation {
@@ -406,7 +419,7 @@ impl PluginHost {
             let answer = result.get_or_insert_with(|| IndexedSymbol { range: primary.range, files: vec![] });
             for (path, file) in &graph.files {
                 let mut ranges = std::collections::BTreeSet::new();
-                for candidate in &file.edges.definitions {
+                for candidate in file.edges.definitions.iter().filter(|a| !is_empty(a.range)) {
                     if targets.contains(&Location::file(path.clone(), candidate.range))
                         || (targets.is_empty() && file.scope == source.scope && keys.contains(candidate.key.as_str()))
                     {
@@ -414,7 +427,7 @@ impl PluginHost {
                     }
                 }
                 let mut matches = HashMap::new();
-                for candidate in &file.edges.references {
+                for candidate in file.edges.references.iter().filter(|a| !is_empty(a.range)) {
                     let same = *matches.entry(candidate.key.as_str()).or_insert_with(|| {
                         let resolved = graph.scoped_targets(&candidate.key, &file.scope);
                         resolved.iter().any(|target| targets.contains(target))
@@ -580,3 +593,21 @@ impl ExtensionPoint for IndexersPoint {
         Ok(Prepared::new(d.extensions.join(", "), || Ok(Disposable::new(|| {}))).capability(Capability::ProjectRead))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn empty_ranges_inside_the_document_are_valid_positions() {
+        let lines = [3, 0];
+        let range = |a: (u32, u32), b: (u32, u32)| Range::new(Pos::new(a.0, a.1), Pos::new(b.0, b.1));
+        assert!(valid_range(&lines, range((0, 0), (0, 0))));
+        assert!(valid_range(&lines, range((1, 0), (1, 0))));
+        assert!(valid_range(&lines, range((0, 1), (0, 3))));
+        assert!(!valid_range(&lines, range((0, 2), (0, 1))), "reversed");
+        assert!(!valid_range(&lines, range((0, 4), (0, 4))), "past the line end");
+        assert!(!valid_range(&lines, range((2, 0), (2, 0))), "past the last line");
+        assert!(is_empty(range((0, 0), (0, 0))) && !is_empty(range((0, 0), (0, 1))));
+    }
+}

crates/ide-host/src/plugins/remote_host.rs

@@ -165,6 +165,7 @@ pub fn forwarded(event: &PluginEvent) -> bool {
             | PluginEvent::OpenProject { .. }
             | PluginEvent::PromptRequested { .. }
             | PluginEvent::PromptClosed { .. }
+            | PluginEvent::PromptWaiting { .. }
             | PluginEvent::RevealView { .. }
             | PluginEvent::CommitRequested { .. }
             | PluginEvent::EndpointsChanged { .. }

crates/ide-host/src/plugins/types.rs

@@ -321,6 +321,10 @@ pub enum PluginEvent {
     /// The call that asked gave up (cancelled, or its plugin stopped): close the prompt.
     #[serde(rename_all = "camelCase")]
     PromptClosed { prompt_id: String },
+    /// A command of this window's prompting plugin was run from another window and refused
+    /// while the plugin waits for the answer here: bring this window to the front.
+    #[serde(rename_all = "camelCase")]
+    PromptWaiting { plugin_id: String },
     /// Bring the tool window of the plugin's view `view` to the front.
     #[serde(rename_all = "camelCase")]
     RevealView { plugin_id: String, view: String },

crates/ide-host/src/project.rs

@@ -13,7 +13,7 @@ use ide_vfs::Watcher;
 use ide_workspace::documents::DocumentObserver;
 use ide_workspace::{DocumentInfo, Documents, FileMoves, LocalHistory, ProjectRoots, SettingsStore, SourceFolder};
 use parking_lot::{Mutex, RwLock};
-use std::collections::{BTreeMap, HashMap};
+use std::collections::{BTreeMap, HashMap, HashSet};
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
@@ -50,6 +50,8 @@ pub struct Project {
     pub cache_dir: PathBuf,
     /// Superseded launch snapshots retained until this project session ends.
     pub(crate) java_launch_snapshots: Mutex<crate::ops::java::cache::Session>,
+    /// Reasons this window was already told why Kotlin is debugged with kotlin-debug-adapter.
+    pub(crate) kotlin_debug_notices: Mutex<HashSet<&'static str>>,
     /// Database tool window: data sources and their connections.
     pub db: Arc<ide_db::DbManager>,
     /// HTTP Client responses (IDEA's `.idea/httpRequests`), in the app data dir.
@@ -563,6 +565,7 @@ impl Host {
             java_launch_snapshots: Mutex::new(crate::ops::java::cache::Session::new(
                 self.local_data_dir.join("cache").join(&project_key).join("build"),
             )),
+            kotlin_debug_notices: Mutex::default(),
             db,
             http_history,
             agents,
@@ -596,6 +599,12 @@ impl Host {
                 weak.upgrade().map(|p| p.exclude_globs()).unwrap_or_default()
             }));
         }
+        {
+            let weak = Arc::downgrade(&project);
+            project.agents.set_security_hook(Arc::new(move || {
+                weak.upgrade().map(|p| p.settings.effective().agent_security).unwrap_or_default()
+            }));
+        }
         self.insert_project(window, project.clone());
         project.lsp.prewarm_java_configuration();
         if let Some(bridge) = &project.kotlin_bridge {
@@ -718,6 +727,7 @@ impl Host {
             java_launch_snapshots: Mutex::new(crate::ops::java::cache::Session::new(
                 self.local_data_dir.join("cache").join(&project_key).join("build"),
             )),
+            kotlin_debug_notices: Mutex::default(),
             db,
             http_history,
             agents,
@@ -1221,7 +1231,7 @@ fn content_roots(settings: &ide_core::settings::Settings, root: &Path, build_cac
 
 /// The roots a file may navigate into: its own root (the workspace member containing it, or
 /// the project root) plus that root's configured dependencies. A workspace member depends
-/// only on the roots picked per member in Settings › Project Structure › Dependencies —
+/// only on the roots picked per member in Project Structure › Dependencies —
 /// being attached to the workspace never makes its code navigable by itself.
 /// Cached navigation roots per (project, file), with the instant they were computed.
 type NavigationRootsCache = HashMap<(PathBuf, PathBuf), (Instant, Vec<PathBuf>)>;

crates/ide-host/tests/external_log.rs

@@ -93,9 +93,15 @@ async fn external_history_is_readable_and_never_becomes_a_write_target() {
     let payload =
         serde_json::to_vec(&serde_json::json!({ "repo": external, "revision": first, "path": "deleted.txt" })).unwrap();
     let hex = payload.iter().map(|b| format!("{b:02x}")).collect::<String>();
-    let document =
-        vcs::revision_virtual_document(&host, "standalone", &format!("git-revision:{hex}/deleted.txt")).await.unwrap();
+    let uri = format!("git-revision:{hex}/deleted.txt");
+    let document = vcs::revision_virtual_document(&host, "standalone", &uri, None).await.unwrap();
     assert_eq!(document.text, "historical content\n");
+    assert_eq!(document.encoding, "utf-8");
+    assert!(document.can_reload_encoding);
+    // Reload with Encoding re-decodes the blob with the chosen charset.
+    let reloaded = vcs::revision_virtual_document(&host, "standalone", &uri, Some("utf-16le")).await.unwrap();
+    assert_eq!(reloaded.encoding, "utf-16le");
+    assert_ne!(reloaded.text, document.text);
     host.trust.decide(&root, true, false).unwrap();
     let project = host.open_project("main", &root).unwrap();
     assert!(vcs::vcs_log(&host, "main", Some(external.clone()), Default::default()).await.is_err());

crates/ide-host/tests/plugins.rs

@@ -4157,6 +4157,35 @@ fn code_action_resolution_prompts_in_the_editor_window_under_the_command_budget(
     assert!(f.take_events().iter().all(|(_, e)| !matches!(e, PluginEvent::PromptRequested { .. })));
 }
 
+#[test]
+fn a_command_from_another_window_is_refused_while_the_plugin_waits_for_an_answer() {
+    let (f, doc) = interactive_actions_fixture();
+    let action = f
+        .host
+        .provide_code_actions(&doc, ide_core::Range::default())
+        .into_iter()
+        .find(|(_, action)| action.data.as_deref() == Some("pick"))
+        .unwrap()
+        .1;
+    std::thread::scope(|scope| {
+        let running = scope.spawn(|| f.host.resolve_code_action("misbehave", &doc, action, action_invocation()));
+        let (id, _) = action_prompt(&f);
+        // Queued behind the open prompt it would not run until the prompt is answered.
+        let other = Invocation { client: Some("other-window".into()), ..Default::default() };
+        let err = f.host.run_command("misbehave", "anything", None, other).unwrap_err();
+        assert_eq!(err.kind, ErrorKind::InvalidInput);
+        assert!(err.message.contains("waiting for your answer in another window"), "{}", err.message);
+        let events = f.take_events();
+        assert!(
+            events.iter().any(|(client, e)| client.as_deref() == Some("editor-window")
+                && matches!(e, PluginEvent::PromptWaiting { plugin_id } if plugin_id == "misbehave")),
+            "the prompting window is brought forward: {events:?}"
+        );
+        assert!(f.host.answer_prompt(&id, Some(vec!["b".into()])));
+        running.join().unwrap().unwrap();
+    });
+}
+
 #[test]
 fn code_action_prompts_dismiss_cancel_and_close_without_edits_or_hanging() {
     for (how, kind) in [

crates/ide-host/tests/rpc.rs

@@ -330,6 +330,7 @@ async fn local_deployment_runs_on_the_project_host() {
         "remote_delete",
         "remote_mkdir",
         "remote_rename",
+        "remote_download_into",
         "db_sources",
         "db_save_sources",
         "db_set_password",

crates/ide-host/tests/trust.rs

@@ -94,6 +94,7 @@ async fn application_commands_work_in_restricted_projects_and_without_a_project(
         "remote_delete",
         "remote_mkdir",
         "remote_rename",
+        "remote_download_into",
         "remote_import_local",
         "remote_bootstrap_exec",
         "deploy_upload",

crates/ide-http/src/env.rs

@@ -105,6 +105,89 @@ pub fn environment_file(file: &Path, root: Option<&Path>, private: bool) -> IdeR
     Ok(path)
 }
 
+/// Where `{{name}}` is defined in the environment files that apply to `file`: the key `name`
+/// in each environment (and `$shared`) of the nearest private file, then of the nearest public
+/// file — the lookup order. Positions are 0-based lines and UTF-16 columns of the key, quotes
+/// included.
+pub fn variable_definitions(file: &Path, root: Option<&Path>, name: &str) -> Vec<ide_core::Location> {
+    let dirs = search_dirs(Some(file), root);
+    let mut out = Vec::new();
+    for file_name in [PRIVATE_FILE, PUBLIC_FILE] {
+        let Some(path) = dirs.iter().map(|d| d.join(file_name)).find(|p| p.is_file()) else { continue };
+        let Ok(text) = ide_vfs::load_text(&path) else { continue };
+        for range in environment_keys(&text.text, name) {
+            out.push(ide_core::Location { path: path.clone().into(), range, uri: None });
+        }
+    }
+    out
+}
+
+/// The ranges of keys equal to `name` one level inside the top-level object (an
+/// environment's variables), found by scanning the JSON text without building a value.
+fn environment_keys(text: &str, name: &str) -> Vec<ide_core::Range> {
+    use ide_core::{Pos, Range};
+    let mut found = Vec::new();
+    let (mut line, mut col) = (0u32, 0u32);
+    let mut depth = 0usize;
+    let mut chars = text.char_indices().peekable();
+    // Whether the last string closed at depth 2 may be a key: set after `{` or `,`.
+    let mut expect_key = false;
+    while let Some((_, c)) = chars.next() {
+        match c {
+            '"' => {
+                let start = Pos::new(line, col);
+                col += 1;
+                let mut value = String::new();
+                let mut escaped = false;
+                for (_, c) in chars.by_ref() {
+                    col += c.len_utf16() as u32;
+                    if escaped {
+                        value.push(match c {
+                            'n' => '\n',
+                            't' => '\t',
+                            other => other,
+                        });
+                        escaped = false;
+                    } else if c == '\\' {
+                        escaped = true;
+                    } else if c == '"' {
+                        break;
+                    } else {
+                        value.push(c);
+                    }
+                }
+                let end = Pos::new(line, col);
+                if depth == 2 && expect_key && value == name {
+                    let mut rest = chars.clone();
+                    while rest.peek().is_some_and(|(_, c)| c.is_whitespace()) {
+                        rest.next();
+                    }
+                    if rest.peek().is_some_and(|(_, c)| *c == ':') {
+                        found.push(Range { start, end });
+                    }
+                }
+                expect_key = false;
+                continue;
+            }
+            '{' | '[' => {
+                depth += 1;
+                expect_key = c == '{';
+            }
+            '}' | ']' => depth = depth.saturating_sub(1),
+            ',' => expect_key = true,
+            ':' => expect_key = false,
+            '\n' => {
+                line += 1;
+                col = 0;
+                continue;
+            }
+            _ => {}
+        }
+        col += c.len_utf16() as u32;
+    }
+    found
+}
+
 impl Environments {
     pub fn load(file: Option<&Path>, root: Option<&Path>) -> IdeResult<Self> {
         let dirs = search_dirs(file, root);
@@ -221,6 +304,44 @@ impl Resolver<'_> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn finds_variable_keys_in_every_environment_private_first() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        std::fs::create_dir_all(root.join("api")).unwrap();
+        std::fs::write(
+            root.join(PUBLIC_FILE),
+            "{\n  \"$shared\": { \"host\": \"shared\" },\n  \"dev\": {\n    \"name\": \"host\",\n    \"host\": \"localhost\",\n    \"ssl\": { \"host\": \"nested\" }\n  },\n  \"prod\": { \"hostname\": \"x\", \"host\": \"example.com\" }\n}\n",
+        )
+        .unwrap();
+        std::fs::write(root.join("api").join(PRIVATE_FILE), "{ \"dev\": { \"😀\": 1, \"host\": \"secret\" } }")
+            .unwrap();
+        let file = root.join("api").join("requests.http");
+        let found = variable_definitions(&file, Some(root), "host");
+        let at: Vec<_> = found
+            .iter()
+            .map(|l| {
+                (
+                    l.path.0.file_name().unwrap().to_string_lossy().into_owned(),
+                    l.range.start.line,
+                    l.range.start.col,
+                    l.range.end.col,
+                )
+            })
+            .collect();
+        assert_eq!(
+            at,
+            vec![
+                (PRIVATE_FILE.to_owned(), 0, 20, 26),
+                (PUBLIC_FILE.to_owned(), 1, 15, 21),
+                (PUBLIC_FILE.to_owned(), 4, 4, 10),
+                (PUBLIC_FILE.to_owned(), 7, 29, 35),
+            ],
+            "values and nested objects are not definitions"
+        );
+        assert!(variable_definitions(&file, Some(root), "missing").is_empty());
+    }
+
     #[test]
     fn merges_private_public_and_shared() {
         let envs = Environments::from_json(

crates/ide-language/src/lib.rs

@@ -55,6 +55,10 @@ pub struct LanguageConfig {
     /// the first one whose root marker is found applies.
     #[serde(default)]
     pub framework_ui_modes: Vec<FrameworkUiMode>,
+    /// Files of this language in a framework's projects that their extension alone would
+    /// give to another language (Django templates are `.html` files in `templates`).
+    #[serde(default)]
+    pub framework_files: Vec<FrameworkFiles>,
     #[serde(default)]
     pub tree_sitter: Option<String>,
     #[serde(default)]
@@ -90,6 +94,18 @@ pub struct FrameworkUiMode {
     pub root_markers: Vec<String>,
 }
 
+/// Files in a framework's folder: a file with one of `extensions` below a folder named
+/// `folder`, which has a root marker in a directory above it.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub struct FrameworkFiles {
+    pub folder: String,
+    /// Without the dot, compared ignoring case.
+    pub extensions: Vec<String>,
+    /// Matched like language servers' `root-markers`, e.g. `manage.py`.
+    pub root_markers: Vec<String>,
+}
+
 #[derive(Clone, Copy, Debug, Serialize, Deserialize, Type)]
 #[serde(rename_all(serialize = "camelCase", deserialize = "kebab-case"))]
 pub struct IndentConfig {

crates/ide-language/src/registry.rs

@@ -22,6 +22,7 @@ const BUILTIN: &[(&str, &str)] = &[
     ("d", include_str!("../../../languages/d.toml")),
     ("dart", include_str!("../../../languages/dart.toml")),
     ("diff", include_str!("../../../languages/diff.toml")),
+    ("django-html", include_str!("../../../languages/django-html.toml")),
     ("dockerfile", include_str!("../../../languages/dockerfile.toml")),
     ("dotenv", include_str!("../../../languages/dotenv.toml")),
     ("elixir", include_str!("../../../languages/elixir.toml")),
@@ -371,14 +372,13 @@ impl LanguageRegistry {
             .map(|f| f.ui_mode.clone())
     }
 
-    /// Creating or removing `path` can change a file's `framework_ui_mode`:
-    /// it is a framework's root marker.
+    /// Creating or removing `path` can change a file's `framework_ui_mode` or its
+    /// language (`framework-files`): it is a framework's root marker.
     pub fn is_framework_marker(&self, path: &Path) -> bool {
-        self.state()
-            .languages
-            .iter()
-            .flat_map(|l| &l.framework_ui_modes)
-            .any(|f| f.root_markers.iter().any(|m| crate::markers::is_marker_path(path, m)))
+        let state = self.state();
+        let modes = state.languages.iter().flat_map(|l| &l.framework_ui_modes).map(|f| &f.root_markers);
+        let files = state.languages.iter().flat_map(|l| &l.framework_files).map(|f| &f.root_markers);
+        modes.chain(files).flatten().any(|m| crate::markers::is_marker_path(path, m))
     }
 
     /// Detects by Override File Type, exact file name, then file-name pattern
@@ -400,6 +400,9 @@ impl LanguageRegistry {
         if let Some((_, i)) = t.name_globs.iter().find(|(p, _)| wildcard_match(p, file_name)) {
             return languages[*i].id.clone();
         }
+        if let Some(l) = languages.iter().find(|l| l.framework_files.iter().any(|f| is_framework_file(f, path))) {
+            return l.id.clone();
+        }
         let lower = file_name.to_ascii_lowercase();
         let mut rest = lower.as_str();
         while let Some(dot) = rest.find('.') {
@@ -420,6 +423,19 @@ impl LanguageRegistry {
     }
 }
 
+/// `path` is one of `files`: its extension is listed, and the nearest folder above it named
+/// `files.folder` has a root marker in a directory above that folder.
+fn is_framework_file(files: &crate::FrameworkFiles, path: &Path) -> bool {
+    let Some(ext) = path.extension().and_then(|e| e.to_str()) else { return false };
+    if !files.extensions.iter().any(|e| e.eq_ignore_ascii_case(ext)) {
+        return false;
+    }
+    path.ancestors()
+        .skip(1)
+        .find(|dir| dir.file_name().is_some_and(|name| name == files.folder.as_str()))
+        .is_some_and(|folder| crate::marked_root(None, folder, &files.root_markers).is_some())
+}
+
 /// `*` matches any (possibly empty) run of characters, `?` exactly one; everything else is literal.
 fn wildcard_match(pattern: &str, name: &str) -> bool {
     let p: Vec<char> = pattern.chars().collect();
@@ -497,6 +513,7 @@ mod tests {
         "Brainfuck",
         "Cobol",
         "C#",
+        "Django Template",
         "Clojure",
         "ClojureScript",
         "Closure Stylesheets (GSS)",
@@ -801,6 +818,36 @@ mod tests {
         assert!(!reg.is_framework_marker(&root.join("apps/admin/package.json")));
     }
 
+    #[test]
+    fn django_projects_make_html_in_templates_folders_templates() {
+        let reg = reg();
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let detect = |file: &str| reg.detect(&root.join(file), None).as_str().to_owned();
+        std::fs::create_dir_all(root.join("src/orders/templates/orders/email")).unwrap();
+        std::fs::create_dir_all(root.join("site/templates")).unwrap();
+        std::fs::write(root.join("src/manage.py"), "").unwrap();
+        assert_eq!(detect("src/orders/templates/orders/detail.html"), "django-html");
+        assert_eq!(detect("src/orders/templates/orders/email/body.TXT"), "django-html");
+        assert_eq!(detect("src/templates/base.html"), "django-html");
+        assert_eq!(detect("src/orders/templates/orders/data.json"), "json");
+        assert_eq!(detect("src/orders/static/orders/page.html"), "html");
+        // No `manage.py` above this `templates` folder.
+        assert_eq!(detect("site/templates/index.html"), "html");
+        assert_eq!(detect("page.djhtml"), "django-html");
+        assert!(reg.is_framework_marker(&root.join("src/manage.py")));
+    }
+
+    #[test]
+    fn the_django_fixture_has_templates_and_a_page() {
+        let reg = reg();
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../../fixtures/django-app");
+        let detect = |file: &str| reg.detect(&fixture.join(file), None).as_str().to_owned();
+        assert_eq!(detect("shop/templates/shop/product_list.html"), "django-html");
+        assert_eq!(detect("shop/templates/shop/email/order.txt"), "django-html");
+        assert_eq!(detect("pages/promo.html"), "html");
+    }
+
     #[test]
     fn markers_outside_the_project_do_not_make_angular_templates() {
         let reg = reg();

crates/ide-lsp/Cargo.toml

@@ -29,4 +29,5 @@ zip.workspace = true
 
 [dev-dependencies]
 tempfile.workspace = true
+encoding_rs.workspace = true
 tokio = { workspace = true, features = ["rt-multi-thread", "macros", "test-util"] }

crates/ide-lsp/src/go_mod.rs

@@ -0,0 +1,223 @@
+//! go.mod as GoLand shows it: available upgrades, vulnerabilities and deprecated modules are
+//! reported as soon as the file is opened. gopls reports upgrades only from its "Check for
+//! upgrades" code lens, so that runs once per go.mod and session; its results (and the
+//! vulnerabilities from the `vulncheck` setting) come back as gopls diagnostics with quick fixes.
+//! gopls never reports a deprecated module, so `go list -m -u` does, on open and on save.
+
+use crate::LspManager;
+use crate::server::Server;
+use ide_core::{DocId, Pos, Range};
+use serde::Deserialize;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use std::time::Duration;
+
+pub(crate) const CHECK_UPGRADES: &str = "gopls.check_upgrades";
+/// gopls answers code lenses once it has loaded the module.
+const ATTEMPTS: u32 = 10;
+const RETRY: Duration = Duration::from_secs(2);
+/// Producer of the deprecation diagnostics (one full set per go.mod).
+const DEPRECATIONS: &str = "go-mod-deprecations";
+
+fn is_go_mod(path: &Path) -> bool {
+    path.file_name().is_some_and(|n| n == "go.mod")
+}
+
+impl LspManager {
+    pub(crate) async fn check_go_mod(&self, doc: DocId, path: &Path, server: Arc<Server>) {
+        if server.name != "gopls" || !is_go_mod(path) {
+            return;
+        }
+        self.report_deprecated_modules(doc, &server).await;
+        if !self.go_mod_checked.lock().insert(path.to_owned()) {
+            return;
+        }
+        for attempt in 0..ATTEMPTS {
+            if attempt > 0 {
+                tokio::time::sleep(RETRY).await;
+            }
+            if !self.docs.lock().contains_key(&doc) {
+                break;
+            }
+            let Ok(lenses) = self.code_lens(doc).await else { continue };
+            let Some(command) = lenses.into_iter().filter_map(|l| l.command).find(|c| c.command == CHECK_UPGRADES)
+            else {
+                continue;
+            };
+            if let Err(e) = self.execute_command(doc, command).await {
+                tracing::debug!("gopls: {CHECK_UPGRADES} for {}: {}", path.display(), e.message);
+            }
+            return;
+        }
+        // Not checked after all (closed, or gopls never offered the lens): a later open retries.
+        self.go_mod_checked.lock().remove(path);
+    }
+
+    /// After a save of a go.mod: its requirements may have changed.
+    pub(crate) fn go_mod_saved(&self, doc: DocId) {
+        let server = {
+            let docs = self.docs.lock();
+            let Some(d) = docs.get(&doc).filter(|d| is_go_mod(&d.path)) else { return };
+            let Some(a) = d.servers.iter().find(|a| a.server.name == "gopls") else { return };
+            a.server.clone()
+        };
+        let Some(me) = self.me.upgrade() else { return };
+        self.runtime.spawn(async move { me.report_deprecated_modules(doc, &server).await });
+    }
+
+    async fn report_deprecated_modules(&self, doc: DocId, server: &Server) {
+        let Some((path, text)) = self.docs.lock().get(&doc).map(|d| (d.path.clone(), d.text.as_str().to_owned()))
+        else {
+            return;
+        };
+        let required = required_modules(&text);
+        if required.is_empty() {
+            return;
+        }
+        let config = server.effective_config();
+        let search = crate::launch::server_search_path(&config);
+        let Some(dir) = path.parent().map(Path::to_path_buf) else { return };
+        let modules: Vec<String> = required.iter().map(|r| r.path.clone()).collect();
+        let listed = tokio::task::spawn_blocking(move || list_deprecations(&dir, &search, &modules)).await;
+        let Ok(Some(deprecated)) = listed else { return };
+        // The document changed meanwhile: its own save runs again.
+        if self.docs.lock().get(&doc).is_none_or(|d| d.text.as_str() != text) {
+            return;
+        }
+        let items = required
+            .into_iter()
+            .filter_map(|r| {
+                let message = deprecated.iter().find(|(p, _)| *p == r.path)?.1.trim();
+                Some(ide_core::Diagnostic {
+                    range: r.range,
+                    severity: ide_core::Severity::Warning,
+                    message: format!("{} is deprecated: {message}", r.path),
+                    source: Some("go".into()),
+                    code: None,
+                    unnecessary: false,
+                    deprecated: true,
+                    server: Some("gopls".into()),
+                })
+            })
+            .collect();
+        self.sink().emit(ide_core::IdeEvent::Diagnostics { path: path.into(), source: DEPRECATIONS.into(), items });
+    }
+}
+
+#[derive(Debug, PartialEq)]
+struct Required {
+    path: String,
+    /// The module path in go.mod (UTF-16 columns).
+    range: Range,
+}
+
+/// Modules of go.mod's `require` directives, single-line or in a block.
+fn required_modules(text: &str) -> Vec<Required> {
+    let mut out = Vec::new();
+    let mut in_block = false;
+    for (line, raw) in text.lines().enumerate() {
+        let code = raw.split("//").next().unwrap_or("");
+        let trimmed = code.trim_start();
+        let entry = if in_block {
+            if trimmed.starts_with(')') {
+                in_block = false;
+                continue;
+            }
+            trimmed
+        } else if let Some(rest) = trimmed.strip_prefix("require").filter(|r| r.starts_with(char::is_whitespace)) {
+            let rest = rest.trim_start();
+            if rest.starts_with('(') {
+                in_block = true;
+                continue;
+            }
+            rest
+        } else {
+            continue;
+        };
+        let mut words = entry.split_whitespace();
+        let (Some(module), Some(_version)) = (words.next(), words.next()) else { continue };
+        let module = module.trim_matches('"');
+        let Some(start) = code.find(module) else { continue };
+        let col = |byte: usize| code[..byte].encode_utf16().count() as u32;
+        let line = line as u32;
+        out.push(Required {
+            path: module.to_owned(),
+            range: Range { start: Pos { line, col: col(start) }, end: Pos { line, col: col(start + module.len()) } },
+        });
+    }
+    out
+}
+
+#[derive(Deserialize)]
+struct ListedModule {
+    #[serde(rename = "Path")]
+    path: String,
+    #[serde(rename = "Deprecated", default)]
+    deprecated: Option<String>,
+}
+
+/// `(module, message)` of each deprecated module in `modules`; `None` when `go` failed.
+fn list_deprecations(dir: &Path, search: &std::ffi::OsStr, modules: &[String]) -> Option<Vec<(String, String)>> {
+    let go: PathBuf = ide_core::tool_path::find_command("go", search, dir)?;
+    let output = ide_core::process::prepare(&mut std::process::Command::new(go))
+        .args(["list", "-m", "-u", "-e", "-json"])
+        .args(modules)
+        .current_dir(dir)
+        .env("PATH", search)
+        .stdin(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null())
+        .output()
+        .ok()?;
+    if output.stdout.is_empty() {
+        tracing::debug!("go list -m -u in {}: {}", dir.display(), output.status);
+        return None;
+    }
+    Some(parse_deprecations(&output.stdout))
+}
+
+fn parse_deprecations(json: &[u8]) -> Vec<(String, String)> {
+    serde_json::Deserializer::from_slice(json)
+        .into_iter::<ListedModule>()
+        .map_while(Result::ok)
+        .filter_map(|m| Some((m.path, m.deprecated.filter(|d| !d.trim().is_empty())?)))
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn at(line: u32, from: u32, to: u32) -> Range {
+        Range { start: Pos { line, col: from }, end: Pos { line, col: to } }
+    }
+
+    #[test]
+    fn finds_required_modules_in_blocks_and_single_lines() {
+        let text = "module example.com/m\n\ngo 1.24\n\nrequire github.com/a/b v1.0.0 // indirect\n\
+                    require (\n\tgithub.com/c/d v1.2.0\n\t\"github.com/e/é\" v0.1.0 // indirect\n)\n\
+                    // require github.com/x/y v1.0.0\nreplace github.com/c/d => ../d\ntool golang.org/x/tools/cmd/stringer\n";
+        assert_eq!(
+            required_modules(text),
+            vec![
+                Required { path: "github.com/a/b".into(), range: at(4, 8, 22) },
+                Required { path: "github.com/c/d".into(), range: at(6, 1, 15) },
+                Required { path: "github.com/e/é".into(), range: at(7, 2, 16) },
+            ]
+        );
+    }
+
+    #[test]
+    fn reads_deprecations_from_the_go_list_stream() {
+        let json = br#"{"Path": "github.com/golang/protobuf", "Version": "v1.5.4",
+            "Deprecated": "Use the \"google.golang.org/protobuf\" module instead."}
+            {"Path": "github.com/sergi/go-diff", "Version": "v1.3.1"}
+            {"Path": "example.com/blank", "Deprecated": "  "}"#;
+        assert_eq!(
+            parse_deprecations(json),
+            vec![(
+                "github.com/golang/protobuf".to_owned(),
+                "Use the \"google.golang.org/protobuf\" module instead.".to_owned()
+            )]
+        );
+    }
+}

crates/ide-lsp/src/handler.rs

@@ -398,6 +398,9 @@ impl Handler for ClientHandler {
                 }
             }
             "tsserver/request" => mgr.forward_tsserver_requests(self.server.clone(), self.generation, params),
+            "intellij/workspaceImportState" if self.server.name == crate::kotlin_lsp::KOTLIN_LSP => {
+                crate::kotlin_lsp::record_import_state(&self.server, self.generation, &params)
+            }
             "language/status" if self.server.name == "jdtls" && params["type"] == "ServiceReady" => {
                 mgr.java_import_ready(self.server.clone(), self.generation);
             }

crates/ide-lsp/src/jdtls.rs

@@ -16,7 +16,7 @@ use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::{Duration, Instant};
 
-const SERVER: &str = "jdtls";
+pub(crate) const SERVER: &str = "jdtls";
 
 pub(crate) mod configuration;
 mod formatter;

crates/ide-lsp/src/kotlin_lsp.rs

@@ -0,0 +1,195 @@
+//! kotlin-lsp's built-in debug adapter: `start_debug_server` once the server has imported
+//! the project (breakpoints set before that are "verified" but never hit).
+
+use crate::LspManager;
+use crate::server::Server;
+use ide_core::event::ServerStatus;
+use ide_core::{CancellationToken, LanguageId};
+use serde_json::{Value, json};
+use std::path::{Path, PathBuf};
+use std::time::Duration;
+
+/// The server's name in `languages/kotlin.toml`.
+pub const KOTLIN_LSP: &str = "kotlin-lsp";
+/// A cold start imports the Gradle model before answering `initialize`.
+const READY_TIMEOUT: Duration = Duration::from_secs(240);
+const COMMAND_TIMEOUT: Duration = Duration::from_secs(120);
+
+/// The last `intellij/workspaceImportState` of the current instance.
+#[derive(Clone, Debug, PartialEq)]
+pub(crate) struct ImportState {
+    pub finished: bool,
+    /// Workspace folders whose import did not succeed.
+    pub failed: Vec<PathBuf>,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct KotlinDebugServer {
+    /// Local TCP port of the DAP server.
+    pub port: u16,
+    /// Root of the kotlin-lsp instance that serves it.
+    pub root: PathBuf,
+}
+
+/// Why kotlin-lsp cannot debug the module, for the fallback notice.
+#[derive(Clone, Debug, PartialEq)]
+pub enum KotlinDebugUnavailable {
+    /// No `kotlin-lsp` among the module's servers (disabled in settings, another server chosen).
+    NotConfigured,
+    NotInstalled,
+    /// The status message, else the status.
+    NotStarted(String),
+    /// The import did not finish in time, or the wait was cancelled.
+    StillImporting,
+    ImportFailed,
+    Failed(String),
+}
+
+/// Records `intellij/workspaceImportState` from instance `generation`. Completion is this
+/// notification, not "no `$/progress` left": kotlin-lsp reports "Indexing" every few seconds.
+pub(crate) fn record_import_state(server: &Server, generation: u64, params: &Value) {
+    let failed = params["folders"]
+        .as_array()
+        .into_iter()
+        .flatten()
+        .filter(|folder| folder["status"] != "SUCCESS")
+        .filter_map(|folder| folder["folderUri"].as_str().and_then(crate::uri::uri_to_path))
+        .collect();
+    server.set_import_state(generation, ImportState { finished: params["phase"] == "FINISHED", failed });
+}
+
+fn importing(server: &Server) -> bool {
+    server.progress.lock().values().any(|p| p.title.contains("Importing"))
+}
+
+impl LspManager {
+    /// Starts kotlin-lsp's debug server for `path` (a module directory or source file) once
+    /// the project is imported, starting kotlin-lsp if needed. `import_wait` bounds the wait
+    /// for the import after the server is up; cancelling `cancel` ends it as
+    /// [`KotlinDebugUnavailable::StillImporting`].
+    pub async fn kotlin_debug_server(
+        &self,
+        path: &Path,
+        import_wait: Duration,
+        cancel: &CancellationToken,
+    ) -> Result<KotlinDebugServer, KotlinDebugUnavailable> {
+        let server = self
+            .servers_for(&LanguageId::new("kotlin"), path)
+            .into_iter()
+            .find(|s| s.name == KOTLIN_LSP)
+            .ok_or(KotlinDebugUnavailable::NotConfigured)?;
+        self.ensure_started(&server);
+        let ready = tokio::select! {
+            biased;
+            () = cancel.cancelled() => return Err(KotlinDebugUnavailable::StillImporting),
+            ready = server.wait_ready(READY_TIMEOUT) => ready,
+        };
+        if ready.is_none() {
+            let status = server.status();
+            return Err(match status {
+                ServerStatus::Missing => KotlinDebugUnavailable::NotInstalled,
+                ServerStatus::Misconfigured | ServerStatus::Crashed => {
+                    KotlinDebugUnavailable::NotStarted(server.status_message().unwrap_or_else(|| format!("{status:?}")))
+                }
+                _ => KotlinDebugUnavailable::NotStarted(format!("{status:?}")),
+            });
+        }
+        tokio::select! {
+            biased;
+            () = cancel.cancelled() => return Err(KotlinDebugUnavailable::StillImporting),
+            imported = tokio::time::timeout(import_wait, wait_for_import(&server, path)) => {
+                imported.unwrap_or(Err(KotlinDebugUnavailable::StillImporting))?
+            }
+        }
+        // The instance that finished importing, also when it replaced the one waited for.
+        let Some(run) = server.running() else {
+            return Err(KotlinDebugUnavailable::NotStarted(format!("{:?}", server.status())));
+        };
+        let params =
+            json!({ "command": "start_debug_server", "arguments": [crate::uri::path_to_uri_string(&server.root)] });
+        let request = run.peer.request::<Value, Value>("workspace/executeCommand", params, Some(cancel.clone()));
+        let port = match tokio::time::timeout(COMMAND_TIMEOUT, request).await {
+            Ok(Ok(port)) => port,
+            Ok(Err(e)) => return Err(KotlinDebugUnavailable::Failed(e.to_string())),
+            Err(_) => {
+                return Err(KotlinDebugUnavailable::Failed(format!(
+                    "start_debug_server timed out after {} s",
+                    COMMAND_TIMEOUT.as_secs()
+                )));
+            }
+        };
+        match port.as_u64().and_then(|p| u16::try_from(p).ok()).filter(|p| *p != 0) {
+            Some(port) => Ok(KotlinDebugServer { port, root: server.root.clone() }),
+            None => Err(KotlinDebugUnavailable::Failed(format!("unexpected debug server port: {port}"))),
+        }
+    }
+}
+
+/// Waits until the current instance reports its import finished and its "Importing" task
+/// ended, which arrive in either order.
+async fn wait_for_import(server: &Server, path: &Path) -> Result<(), KotlinDebugUnavailable> {
+    let mut state = server.import_state.subscribe();
+    loop {
+        // Created before the check so a progress end in between still wakes us.
+        let progress_ended = server.phase_notified();
+        let current = state.borrow_and_update().clone();
+        if let Some(current) = current
+            && current.finished
+            && !importing(server)
+        {
+            if current.failed.iter().any(|dir| canonical(path).starts_with(canonical(dir))) {
+                return Err(KotlinDebugUnavailable::ImportFailed);
+            }
+            return Ok(());
+        }
+        tokio::select! {
+            _ = state.changed() => {}
+            () = progress_ended => {}
+        }
+    }
+}
+
+/// `path` with its deepest existing ancestor resolved, so a symlinked root (or `/tmp` vs
+/// `/private/tmp` on macOS) and the folder URIs kotlin-lsp reports name one directory alike.
+fn canonical(path: &Path) -> PathBuf {
+    for ancestor in path.ancestors() {
+        if let Ok(real) = dunce::canonicalize(ancestor) {
+            let rest = path.strip_prefix(ancestor).unwrap_or(Path::new(""));
+            return if rest.as_os_str().is_empty() { real } else { real.join(rest) };
+        }
+    }
+    path.to_path_buf()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ide_core::{IdeEvent, SharedSink};
+    use std::sync::Arc;
+
+    #[test]
+    fn an_instance_that_was_replaced_does_not_record_its_import() {
+        let cfg = toml::from_str("name = \"kotlin-lsp\"\ncommand = \"kotlin-lsp\"").unwrap();
+        let server = Server::new(cfg, PathBuf::from("/p"), LanguageId::new("kotlin"));
+        let finished = json!({ "phase": "FINISHED", "folders": [
+            { "folderUri": "file:///p/", "status": "SUCCESS" },
+            { "folderUri": "file:///p/lib/", "status": "FAILED" },
+        ]});
+        let old = server.begin_start().unwrap();
+        record_import_state(&server, old, &json!({ "phase": "IN_PROGRESS", "folders": [] }));
+        assert_eq!(*server.import_state.borrow(), Some(ImportState { finished: false, failed: vec![] }));
+        record_import_state(&server, old, &finished);
+        let done = Some(ImportState { finished: true, failed: vec![PathBuf::from("/p/lib")] });
+        assert_eq!(*server.import_state.borrow(), done);
+
+        let sink: SharedSink = Arc::new(|_: IdeEvent| {});
+        server.begin_stop(&sink, false);
+        let new = server.begin_start().unwrap();
+        assert_eq!(*server.import_state.borrow(), None);
+        // The dying instance's FINISHED arrives after the restart.
+        record_import_state(&server, old, &finished);
+        assert_eq!(*server.import_state.borrow(), None);
+        record_import_state(&server, new, &finished);
+        assert_eq!(*server.import_state.borrow(), done);
+    }
+}

crates/ide-lsp/src/launch.rs

@@ -146,7 +146,7 @@ fn required_env_set(config: &LanguageServerConfig) -> bool {
 }
 
 /// A configured `PATH` (e.g. a selected toolchain prepended) also resolves the binary.
-fn server_search_path(config: &LanguageServerConfig) -> OsString {
+pub(crate) fn server_search_path(config: &LanguageServerConfig) -> OsString {
     config.env.get("PATH").map(OsString::from).unwrap_or_else(search_path)
 }
 

crates/ide-lsp/src/lib.rs

@@ -15,11 +15,13 @@ mod convert;
 mod external_project;
 mod file_ops;
 mod file_watch;
+mod go_mod;
 mod go_scope;
 mod handler;
 mod injections;
 mod inspect;
 pub mod jdtls;
+mod kotlin_lsp;
 mod launch;
 mod library_source;
 mod loading;
@@ -38,6 +40,7 @@ mod vue_navigation;
 pub use injections::{InjectedRange, InjectionProvider, MAX_INJECTED_DOCUMENT_BYTES};
 pub use inspect::{FileInspection, InspectHost, InspectOptions};
 pub use jdtls::jvm_inspect::JdtJvmInspector;
+pub use kotlin_lsp::{KotlinDebugServer, KotlinDebugUnavailable};
 pub use launch::{LaunchError, Launcher, ProcessLauncher};
 pub use scope::{CandidateFiles, CandidateFn, CandidateQuery, MAX_CANDIDATES};
 pub use uri::{is_virtual_uri, path_to_uri_string, uri_target, uri_to_path};
@@ -219,6 +222,8 @@ pub struct LspManager {
     configuration_cache: Arc<Mutex<jdtls::configuration::ConfigurationCache>>,
     /// `window/showMessage` texts already surfaced; servers repeat them on every restart/reconfigure.
     shown_messages: Mutex<HashSet<(String, String)>>,
+    /// go.mod files whose upgrades gopls has been asked to check this session.
+    go_mod_checked: Mutex<HashSet<PathBuf>>,
     /// Virtual (non-`file:`) URIs a server returned, by the server that owns them.
     virtual_origins: Mutex<HashMap<String, ide_core::ServerId>>,
     /// Contents fetched for virtual URIs.
@@ -317,9 +322,48 @@ impl<T> Outcome<T> {
     }
 }
 
+/// How often a rename the server withdrew (`ContentModified`) is asked, and the pause between.
+const RENAME_ATTEMPTS: u32 = 5;
+const RENAME_RETRY_DELAY: std::time::Duration = std::time::Duration::from_millis(300);
+
 /// Implementation requests of one line-marker pass in flight at once.
 const IMPLEMENTATION_CONCURRENCY: usize = 4;
 
+/// How a virtual document's content was decoded, and whether it can be
+/// re-decoded ("Reload with Encoding").
+struct Decoding {
+    encoding: String,
+    has_bom: bool,
+    can_reload: bool,
+}
+
+impl Decoding {
+    /// Text the server decoded itself: no raw bytes here to re-read.
+    fn server_text() -> Self {
+        Decoding { encoding: "utf-8".into(), has_bom: false, can_reload: false }
+    }
+}
+
+/// jdtls' source attachment of a `jdt:` class (`java.project.resolveSourceAttachment`).
+struct SourceAttachment {
+    path: Option<String>,
+    encoding: Option<String>,
+    can_edit_encoding: bool,
+}
+
+/// Reads a `jar:` document's source: an entry as is, a class from the sources
+/// jar next to its binary. `encoding` decodes with it instead of detecting.
+fn read_jar_source(uri: &str, encoding: Option<&str>) -> Option<(String, ide_vfs::LoadedText)> {
+    match library_source::parse(uri) {
+        Some(e) if !e.entry.ends_with(".class") => {
+            library_source::read_entry(&e.jar, &e.entry, encoding).map(|loaded| (e.entry, loaded))
+        }
+        Some(_) => library_source::class_source(uri, encoding)
+            .and_then(|(source, loaded)| Some((library_source::parse(&source)?.entry, loaded))),
+        None => None,
+    }
+}
+
 /// Library classes in `jar:` targets (the official Kotlin LSP) go to their source
 /// in the artifact's sources jar when it is cached, at the declaration of the
 /// name navigated from; [`LspManager::virtual_document`] serves it.
@@ -334,8 +378,9 @@ async fn library_sources(snap: &DocSnap, pos: Pos, locs: Vec<Location>) -> Vec<L
                 let Some(uri) = loc.uri.as_deref().filter(|u| u.starts_with("jar:") && u.ends_with(".class")) else {
                     return loc;
                 };
-                let Some((source, text)) = library_source::class_source(uri) else { return loc };
-                let range = name.as_deref().map(|n| library_source::declaration_range(&text, n)).unwrap_or_default();
+                let Some((source, loaded)) = library_source::class_source(uri, None) else { return loc };
+                let range =
+                    name.as_deref().map(|n| library_source::declaration_range(&loaded.text, n)).unwrap_or_default();
                 Location { path: source.clone().into(), range, uri: Some(source) }
             })
             .collect()
@@ -427,6 +472,7 @@ impl LspManager {
             debug_servers: Mutex::new(HashMap::new()),
             configuration_cache: Arc::new(Mutex::new(Default::default())),
             shown_messages: Mutex::new(HashSet::new()),
+            go_mod_checked: Mutex::new(HashSet::new()),
             virtual_origins: Mutex::new(HashMap::new()),
             virtual_docs: Mutex::new(HashMap::new()),
             injections: injections::State::default(),
@@ -1026,6 +1072,7 @@ impl LspManager {
         servers: Vec<Arc<Server>>,
     ) {
         let canonical = dunce::canonicalize(&path).unwrap_or_else(|_| path.clone());
+        let canonical_path = canonical.clone();
         let compose_detected = language.as_str() == "yaml" && compose::is_content_detected_compose_file(&path, text);
         let mut state = DocState {
             path,
@@ -1056,6 +1103,13 @@ impl LspManager {
         self.schedule_pull(doc, None, Duration::ZERO);
         for s in &servers {
             self.ensure_started(s);
+            // Waits for a server still starting, so it is not tied to `running()` below.
+            if s.name == "gopls"
+                && let Some(me) = self.me.upgrade()
+            {
+                let (path, server) = (canonical_path.clone(), s.clone());
+                self.runtime.spawn(async move { me.check_go_mod(doc, &path, server).await });
+            }
             if s.running().is_some()
                 && let Some(me) = self.me.upgrade()
             {
@@ -1197,6 +1251,7 @@ impl LspManager {
         drop(docs);
         self.schedule_pull(doc, None, Duration::ZERO);
         self.pull_dependents(doc);
+        self.go_mod_saved(doc);
     }
 
     pub fn did_close(&self, doc: DocId) {
@@ -2374,8 +2429,25 @@ impl LspManager {
         let query = || async {
             let mut params = snap.pos_params(t, pos);
             params["newName"] = json!(new_name);
-            let r: Option<lsp::WorkspaceEdit> =
-                self.call(t, "textDocument/rename", params, Some(cancel), LONG_TIMEOUT).await?;
+            // A server still analysing an edit withdraws the rename (`ContentModified`, which
+            // arrives as a cancellation). The user asked for it: ask again shortly instead of
+            // dropping it without a word, and say why if it keeps being withdrawn.
+            let mut attempt = 0;
+            let r: Option<lsp::WorkspaceEdit> = loop {
+                match self.call(t, "textDocument/rename", params.clone(), Some(cancel), LONG_TIMEOUT).await {
+                    Err(e) if e.kind == ide_core::error::ErrorKind::Cancelled && !cancel.is_cancelled() => {
+                        attempt += 1;
+                        if attempt >= RENAME_ATTEMPTS {
+                            return Err(IdeError::invalid(format!(
+                                "{} was still analysing a change and withdrew the rename; try again",
+                                t.server.name
+                            )));
+                        }
+                        tokio::time::sleep(RENAME_RETRY_DELAY).await;
+                    }
+                    r => break r?,
+                }
+            };
             Ok(r.map(|e| convert::workspace_edit(&self.conv(t.enc()), e)).unwrap_or_default())
         };
         // The Angular server renames in the file's own project only, whatever is open.
@@ -2997,8 +3069,9 @@ impl LspManager {
         let original = uri.to_owned();
         let archive = sources.clone();
         let found = tokio::task::spawn_blocking(move || {
-            library_source::source_in_archive(&original, &archive).map(|(uri, text)| {
-                let range = name.as_deref().map(|n| library_source::declaration_range(&text, n)).unwrap_or_default();
+            library_source::source_in_archive(&original, &archive, None).map(|(uri, loaded)| {
+                let range =
+                    name.as_deref().map(|n| library_source::declaration_range(&loaded.text, n)).unwrap_or_default();
                 Location { path: uri.clone().into(), uri: Some(uri), range }
             })
         })
@@ -3040,28 +3113,10 @@ impl LspManager {
         if scheme == "jar" {
             let found = {
                 let uri = uri.to_owned();
-                tokio::task::spawn_blocking(move || match library_source::parse(&uri) {
-                    Some(e) if !e.entry.ends_with(".class") => {
-                        library_source::read_entry(&e.jar, &e.entry).map(|text| (e.entry, text))
-                    }
-                    Some(_) => library_source::class_source(&uri)
-                        .and_then(|(source, text)| Some((library_source::parse(&source)?.entry, text))),
-                    None => None,
-                })
-                .await
-                .ok()
-                .flatten()
+                tokio::task::spawn_blocking(move || read_jar_source(&uri, None)).await.ok().flatten()
             };
-            if let Some((entry, text)) = found {
-                let title = entry.rsplit('/').next().unwrap_or(&entry).to_owned();
-                return Ok(self.store_virtual(
-                    uri,
-                    text,
-                    Some(title),
-                    None,
-                    &[],
-                    self.origin_server(uri).map(|s| s.id),
-                ));
+            if let Some((entry, loaded)) = found {
+                return Ok(self.store_jar_entry(uri, entry, loaded));
             }
         }
         let class_file = scheme == "jdt" || (scheme == "file" && uri.ends_with(".class"));
@@ -3132,7 +3187,21 @@ impl LspManager {
                     continue;
                 }
             };
-            return Ok(self.store_virtual(uri, text, None, description, &languages, Some(t.server.id)));
+            // jdtls decodes attached sources itself: its attachment encoding is
+            // the document's real charset, and editable ones can be re-decoded.
+            let decoding = if scheme == "jdt" && t.server.name == jdtls::SERVER && !virtual_doc::is_decompiled(&text) {
+                match self.jdt_source_attachment(uri).await {
+                    Some(att) if att.path.is_some() => Decoding {
+                        encoding: att.encoding.unwrap_or_else(|| "utf-8".into()),
+                        has_bom: false,
+                        can_reload: att.can_edit_encoding,
+                    },
+                    _ => Decoding::server_text(),
+                }
+            } else {
+                Decoding::server_text()
+            };
+            return Ok(self.store_virtual(uri, text, None, description, &languages, Some(t.server.id), decoding));
         }
         if jar_class && error.is_none() {
             return Err(IdeError::not_found(format!(
@@ -3144,6 +3213,7 @@ impl LspManager {
     }
 
     /// Caches `text` as the virtual document `uri`, titled `title` (else after the URI).
+    #[allow(clippy::too_many_arguments)]
     fn store_virtual(
         &self,
         uri: &str,
@@ -3152,6 +3222,7 @@ impl LspManager {
         description: Option<String>,
         languages: &[LanguageId],
         server: Option<ide_core::ServerId>,
+        decoding: Decoding,
     ) -> VirtualDocument {
         let decompiled = if virtual_doc::scheme(uri) == "csharp" {
             virtual_doc::is_csharp_decompiled(uri)
@@ -3172,6 +3243,9 @@ impl LspManager {
             title,
             description: description.or_else(|| virtual_doc::description(uri)),
             decompiled,
+            encoding: decoding.encoding,
+            has_bom: decoding.has_bom,
+            can_reload_encoding: decoding.can_reload,
         };
         if let Some(server) = server {
             self.virtual_origins.lock().entry(uri.to_owned()).or_insert(server);
@@ -3184,6 +3258,163 @@ impl LspManager {
         doc
     }
 
+    /// Caches a decoded `jar:` entry under the document's original URI, titled
+    /// after the entry; the backend owns these bytes, so they can be re-decoded.
+    fn store_jar_entry(&self, uri: &str, entry: String, loaded: ide_vfs::LoadedText) -> VirtualDocument {
+        let title = entry.rsplit('/').next().unwrap_or(&entry).to_owned();
+        self.store_virtual(
+            uri,
+            loaded.text,
+            Some(title),
+            None,
+            &[],
+            self.origin_server(uri).map(|s| s.id),
+            Decoding { encoding: loaded.encoding, has_bom: loaded.has_bom, can_reload: true },
+        )
+    }
+
+    /// The source attachment jdtls resolves for a `jdt:` class; `None` when the
+    /// command is unavailable or the class's container cannot be queried.
+    async fn jdt_source_attachment(&self, uri: &str) -> Option<SourceAttachment> {
+        let result = self
+            .jdtls_command(
+                &self.project_root,
+                "java.project.resolveSourceAttachment",
+                vec![json!({ "classFileUri": uri })],
+            )
+            .await
+            .ok()?;
+        if result.get("errorMessage").and_then(Value::as_str).is_some_and(|s| !s.is_empty()) {
+            return None;
+        }
+        let attrs = result.get("attributes")?;
+        let non_empty = |key: &str| attrs.get(key).and_then(Value::as_str).filter(|s| !s.is_empty()).map(str::to_owned);
+        Some(SourceAttachment {
+            path: non_empty("sourceAttachmentPath"),
+            encoding: non_empty("sourceAttachmentEncoding"),
+            can_edit_encoding: attrs.get("canEditEncoding").and_then(Value::as_bool).unwrap_or(true),
+        })
+    }
+
+    /// Updates a `jdt:` class's source attachment encoding. The command drops
+    /// the attachment when the path is omitted, so the resolved path is always
+    /// sent along with the encoding.
+    async fn update_jdt_source_encoding(&self, uri: &str, path: &str, encoding: &str) -> IdeResult<()> {
+        let result = self
+            .jdtls_command(
+                &self.project_root,
+                "java.project.updateSourceAttachment",
+                vec![json!({
+                    "classFileUri": uri,
+                    "attributes": { "sourceAttachmentPath": path, "sourceAttachmentEncoding": encoding },
+                })],
+            )
+            .await?;
+        if let Some(error) = result.get("errorMessage").and_then(Value::as_str).filter(|s| !s.is_empty()) {
+            return Err(IdeError::unavailable(error));
+        }
+        Ok(())
+    }
+
+    /// Waits until the resolved attachment reports `encoding`; `false` once
+    /// `until` passes. Maven applies attachment updates in a background job,
+    /// so the new encoding is not visible immediately after the update.
+    async fn wait_for_jdt_source_encoding(&self, uri: &str, encoding: &str, until: tokio::time::Instant) -> bool {
+        loop {
+            match self.jdt_source_attachment(uri).await {
+                Some(att) if att.encoding.as_deref() == Some(encoding) => return true,
+                _ if tokio::time::Instant::now() < until => {
+                    tokio::time::sleep(std::time::Duration::from_millis(150)).await;
+                }
+                _ => return false,
+            }
+        }
+    }
+
+    /// "Reload with Encoding" for a virtual document: re-reads its origin with
+    /// `encoding` and replaces the cached content. `jar:` entries are re-read
+    /// here; `jdt:` sources are decoded by jdtls, so its source attachment
+    /// encoding is updated and the contents fetched again (keeping the server's
+    /// text and positions in sync). Server-generated content cannot be re-decoded.
+    pub async fn reload_virtual(&self, uri: &str, encoding: &str) -> IdeResult<VirtualDocument> {
+        ide_vfs::encode("", encoding, false)?;
+        match virtual_doc::scheme(uri) {
+            "jar" => {
+                let (owned_uri, owned_encoding) = (uri.to_owned(), encoding.to_owned());
+                let found = tokio::task::spawn_blocking(move || read_jar_source(&owned_uri, Some(&owned_encoding)))
+                    .await
+                    .map_err(|e| IdeError::internal(e.to_string()))?;
+                let Some((entry, loaded)) = found else {
+                    return Err(IdeError::not_found(format!(
+                        "no source is available for {}",
+                        virtual_doc::title(uri, false)
+                    )));
+                };
+                Ok(self.store_jar_entry(uri, entry, loaded))
+            }
+            "jdt" if self.origin_server(uri).is_none_or(|s| s.name == jdtls::SERVER) => {
+                let Some(att) = self.jdt_source_attachment(uri).await else {
+                    return Err(IdeError::unavailable("jdtls cannot resolve the source attachment of this class"));
+                };
+                let Some(path) = att.path else {
+                    return Err(IdeError::invalid("this class has no attached sources to re-decode"));
+                };
+                if !att.can_edit_encoding {
+                    return Err(IdeError::invalid("the source attachment encoding of this library cannot be changed"));
+                }
+                self.update_jdt_source_encoding(uri, &path, encoding).await?;
+                // Maven containers apply the update in a background job (persist
+                // attached sources, then refresh the classpath): wait until the
+                // resolved attachment reports the new encoding, else the refetch
+                // below would still decode with the old one.
+                let deadline = tokio::time::Instant::now() + std::time::Duration::from_secs(10);
+                let first_try = tokio::time::Instant::now() + std::time::Duration::from_secs(3);
+                if !self.wait_for_jdt_source_encoding(uri, encoding, first_try).await {
+                    // jdtls matches the existing encoding attribute by reference
+                    // (`==`), so an entry restored from the saved container state
+                    // gains a duplicate attribute and keeps the old value. That
+                    // update still refreshes the container, after which a second
+                    // update replaces the value correctly.
+                    self.update_jdt_source_encoding(uri, &path, encoding).await?;
+                    if !self.wait_for_jdt_source_encoding(uri, encoding, deadline).await {
+                        return Err(IdeError::unavailable(
+                            "jdtls did not apply the source attachment encoding; try reloading again",
+                        ));
+                    }
+                }
+                // JDT keeps the class file's decoded buffer cached, so
+                // classFileContents would still return the old decoding: re-read
+                // the attached source entry here, like `jar:` documents. The
+                // server's open document is kept in sync by the regular
+                // document change flow.
+                let (owned_uri, owned_path, owned_encoding) = (uri.to_owned(), path.clone(), encoding.to_owned());
+                let found = tokio::task::spawn_blocking(move || {
+                    library_source::source_in_archive(&owned_uri, Path::new(&owned_path), Some(&owned_encoding))
+                })
+                .await
+                .map_err(|e| IdeError::internal(e.to_string()))?;
+                if let Some((_source_uri, loaded)) = found {
+                    return Ok(self.store_virtual(
+                        uri,
+                        loaded.text,
+                        None,
+                        None,
+                        &[],
+                        self.origin_server(uri).map(|s| s.id),
+                        Decoding { encoding: loaded.encoding, has_bom: loaded.has_bom, can_reload: true },
+                    ));
+                }
+                // Attachments that are not readable archives (e.g. folders):
+                // fall back to the server's contents.
+                self.virtual_docs.lock().remove(uri);
+                self.virtual_document(uri).await
+            }
+            _ => Err(IdeError::invalid(
+                "this document's content is generated by a language server and cannot be re-decoded with another encoding",
+            )),
+        }
+    }
+
     /// Called when a server sends `workspace/applyEdit`; installed by `src-tauri`
     /// so edits flow through `ide-workspace::Documents`.
     pub fn set_config_hook(&self, hook: Box<ConfigFn>) {

crates/ide-lsp/src/library_source.rs

@@ -7,8 +7,8 @@
 //! it in the Maven or Gradle cache.
 
 use ide_core::{Pos, Range};
+use ide_vfs::LoadedText;
 use percent_encoding::{AsciiSet, CONTROLS, percent_decode_str, utf8_percent_encode};
-use std::io::Read;
 use std::path::{Path, PathBuf};
 
 /// An entry of an archive named by a `jar:` URI.
@@ -57,29 +57,32 @@ impl JarEntry {
     }
 }
 
-/// The text of `entry` in the archive `jar`, when it is a UTF-8 file.
-pub(crate) fn read_entry(jar: &Path, entry: &str) -> Option<String> {
-    let mut zip = zip::ZipArchive::new(std::fs::File::open(jar).ok()?).ok()?;
-    let mut file = zip.by_name(entry).ok()?;
-    let mut text = String::new();
-    file.read_to_string(&mut text).ok()?;
-    Some(text)
+/// The text of `entry` in the archive `jar`, decoded like a file opened in the
+/// editor; `encoding` decodes with it instead of detecting ("Reload with
+/// Encoding"). `None` for binary or unreadable entries.
+pub(crate) fn read_entry(jar: &Path, entry: &str, encoding: Option<&str>) -> Option<LoadedText> {
+    let path = ide_vfs::archive_entry_path(jar, entry);
+    let loaded = match encoding {
+        Some(enc) => ide_vfs::load_text_as(&path, enc).ok()?,
+        None => ide_vfs::load_text(&path).ok()?,
+    };
+    (!loaded.binary).then_some(loaded)
 }
 
 /// The library source for a class entry: its `.kt` / `.java` file in the
 /// artifact's sources jar, as `(uri, text)`.
-pub(crate) fn class_source(uri: &str) -> Option<(String, String)> {
+pub(crate) fn class_source(uri: &str, encoding: Option<&str>) -> Option<(String, LoadedText)> {
     let jar = parse(uri)?;
     let class = jar.entry.strip_suffix(".class")?;
     for sources in sources_jars(&jar.jar) {
-        if let Some((entry, text)) = source_entry(&sources, class) {
+        if let Some((entry, text)) = source_entry(&sources, class, encoding) {
             return Some((jar.uri_of(&sources, &entry), text));
         }
     }
     None
 }
 
-pub(crate) fn source_in_archive(uri: &str, sources: &Path) -> Option<(String, String)> {
+pub(crate) fn source_in_archive(uri: &str, sources: &Path, encoding: Option<&str>) -> Option<(String, LoadedText)> {
     let jar = if uri.starts_with("jdt://contents/") {
         let path = uri.split('?').next()?.strip_prefix("jdt://contents/")?;
         let parts: Vec<_> = path.split('/').collect();
@@ -96,7 +99,7 @@ pub(crate) fn source_in_archive(uri: &str, sources: &Path) -> Option<(String, St
         parse(uri)?
     };
     let class = jar.entry.strip_suffix(".class")?;
-    let (entry, text) = source_entry(sources, class)?;
+    let (entry, text) = source_entry(sources, class, encoding)?;
     Some((jar.uri_of(sources, &entry), text))
 }
 
@@ -117,8 +120,8 @@ fn sources_jars(jar: &Path) -> Vec<PathBuf> {
 }
 
 /// The source file of `class` (`pkg/Name`, `pkg/Outer$Inner`, `pkg/FileKt`) in `sources`.
-fn source_entry(sources: &Path, class: &str) -> Option<(String, String)> {
-    let mut zip = zip::ZipArchive::new(std::fs::File::open(sources).ok()?).ok()?;
+fn source_entry(sources: &Path, class: &str, encoding: Option<&str>) -> Option<(String, LoadedText)> {
+    let zip = zip::ZipArchive::new(std::fs::File::open(sources).ok()?).ok()?;
     let (package, name) = class.rsplit_once('/').unwrap_or(("", class));
     let outer = name.split('$').next().unwrap_or(name);
     let dir = if package.is_empty() { String::new() } else { format!("{package}/") };
@@ -127,13 +130,9 @@ fn source_entry(sources: &Path, class: &str) -> Option<(String, String)> {
     if let Some(file) = outer.strip_suffix("Kt").filter(|f| !f.is_empty()) {
         candidates.push(format!("{dir}{file}.kt"));
     }
-    let read = |zip: &mut zip::ZipArchive<std::fs::File>, entry: &str| {
-        let mut text = String::new();
-        zip.by_name(entry).ok()?.read_to_string(&mut text).ok()?;
-        Some(text)
-    };
+    let read = |entry: &str| read_entry(sources, entry, encoding);
     for entry in &candidates {
-        if let Some(text) = read(&mut zip, entry) {
+        if let Some(text) = read(entry) {
             return Some((entry.clone(), text));
         }
     }
@@ -145,8 +144,8 @@ fn source_entry(sources: &Path, class: &str) -> Option<(String, String)> {
         .collect();
     let jvm_name = format!("@file:JvmName(\"{outer}\")");
     for entry in kotlin_files {
-        if let Some(text) = read(&mut zip, &entry)
-            && text.contains(&jvm_name)
+        if let Some(text) = read(&entry)
+            && text.text.contains(&jvm_name)
         {
             return Some((entry, text));
         }
@@ -233,11 +232,15 @@ mod tests {
     use std::io::Write;
 
     fn jar(path: &Path, entries: &[(&str, &str)]) {
+        jar_bytes(path, &entries.iter().map(|(n, t)| (*n, t.as_bytes())).collect::<Vec<_>>());
+    }
+
+    fn jar_bytes(path: &Path, entries: &[(&str, &[u8])]) {
         std::fs::create_dir_all(path.parent().unwrap()).unwrap();
         let mut zip = zip::ZipWriter::new(std::fs::File::create(path).unwrap());
-        for (name, text) in entries {
+        for (name, bytes) in entries {
             zip.start_file(*name, zip::write::SimpleFileOptions::default()).unwrap();
-            zip.write_all(text.as_bytes()).unwrap();
+            zip.write_all(bytes).unwrap();
         }
         zip.finish().unwrap();
     }
@@ -274,12 +277,12 @@ mod tests {
             "jdt://contents/lib-1.jar/p/Lib.java?=project/escaped-jar-path",
             "jar:file:///m2/g/lib/1/lib-1.jar!/p/Lib$Inner.class",
         ] {
-            let (uri, text) = source_in_archive(uri, &sources).unwrap();
+            let (uri, text) = source_in_archive(uri, &sources, None).unwrap();
             assert!(uri.ends_with("library%20sources.zip!/p/Lib.java"), "{uri}");
-            assert!(text.contains("class Lib"));
+            assert!(text.text.contains("class Lib"));
         }
-        assert!(source_in_archive("jdt://contents/lib.jar/p/Missing.class", &sources).is_none());
-        assert!(source_in_archive("csharp:/p/App.csproj/decompiled/Lib.cs", &sources).is_none());
+        assert!(source_in_archive("jdt://contents/lib.jar/p/Missing.class", &sources, None).is_none());
+        assert!(source_in_archive("csharp:/p/App.csproj/decompiled/Lib.cs", &sources, None).is_none());
     }
 
     #[test]
@@ -312,20 +315,103 @@ mod tests {
                 ("org/springframework/boot/Builder.class", "Builder.kt"),
                 ("Root.class", "Root.java"),
             ] {
-                let (source_uri, text) = class_source(&uri(class)).unwrap_or_else(|| panic!("{class} in {binary:?}"));
+                let (source_uri, text) =
+                    class_source(&uri(class), None).unwrap_or_else(|| panic!("{class} in {binary:?}"));
                 let dir = class.rsplit_once('/').map_or(String::new(), |(p, _)| format!("{p}/"));
                 assert!(source_uri.ends_with(&format!("-sources.jar!/{dir}{file}")), "{source_uri}");
                 assert_eq!(
-                    parse(&source_uri).and_then(|e| read_entry(&e.jar, &e.entry)).as_deref(),
-                    Some(text.as_str())
+                    parse(&source_uri).and_then(|e| read_entry(&e.jar, &e.entry, None)).map(|l| l.text),
+                    Some(text.text.clone())
                 );
             }
-            assert_eq!(class_source(&uri("org/springframework/boot/Missing.class")), None);
+            assert!(class_source(&uri("org/springframework/boot/Missing.class"), None).is_none());
         }
         // No sources jar: nothing to show from here.
         let lone = tmp.path().join("lone/x-1.jar");
         jar(&lone, &[]);
-        assert_eq!(class_source(&format!("jar://{}!/X.class", lone.to_string_lossy().replace('\\', "/"))), None);
+        assert!(class_source(&format!("jar://{}!/X.class", lone.to_string_lossy().replace('\\', "/")), None).is_none());
+    }
+
+    /// The reported case: a library source file saved as GBK bytes, not UTF-8.
+    const GBK_SAMPLE: &str = "package example.encoding;\n\n/** 中文编码测试。 */\npublic final class EncodingSample {\n    public static String message() {\n        return \"中文编码测试：是否启用\";\n    }\n}\n";
+
+    #[test]
+    fn archive_entries_decode_like_files_opened_in_the_editor() {
+        let tmp = tempfile::tempdir().unwrap();
+        let gbk = encoding_rs::GBK.encode(GBK_SAMPLE).0.into_owned();
+        // encoding_rs' encode() falls back to UTF-8 for UTF-16 (WHATWG has no encoder for it).
+        let mut utf16 = vec![0xFF, 0xFE];
+        utf16.extend(GBK_SAMPLE.encode_utf16().flat_map(u16::to_le_bytes));
+        let cases: Vec<(&str, Vec<u8>, &str, &str, bool)> = vec![
+            ("utf8.java", GBK_SAMPLE.as_bytes().to_vec(), GBK_SAMPLE, "utf-8", false),
+            ("bom.java", [b"\xEF\xBB\xBF", GBK_SAMPLE.as_bytes()].concat(), GBK_SAMPLE, "utf-8", true),
+            ("gbk.java", gbk, GBK_SAMPLE, "gbk", false),
+            ("utf16.java", utf16, GBK_SAMPLE, "utf-16le", true),
+        ];
+        for (name, bytes, text, encoding, has_bom) in cases {
+            let jar_path = tmp.path().join(format!("lib-{name}.jar"));
+            jar_bytes(&jar_path, &[(&format!("p/{name}"), &bytes)]);
+            let loaded = read_entry(&jar_path, &format!("p/{name}"), None).unwrap_or_else(|| panic!("{name}"));
+            assert_eq!(loaded.text, text, "{name}");
+            assert_eq!(loaded.encoding, encoding, "{name}");
+            assert_eq!(loaded.has_bom, has_bom, "{name}");
+            assert!(!loaded.binary, "{name}");
+        }
+        // Binary entries are not shown as text.
+        let jar_path = tmp.path().join("bin.jar");
+        jar_bytes(&jar_path, &[("p/img.png", &[0x89, b'P', b'N', b'G', 0, 0, 0, 0])]);
+        assert!(read_entry(&jar_path, "p/img.png", None).is_none());
+        assert!(read_entry(&jar_path, "p/missing.java", None).is_none());
+    }
+
+    #[test]
+    fn reload_decodes_archive_entries_with_the_chosen_encoding() {
+        let tmp = tempfile::tempdir().unwrap();
+        let jar_path = tmp.path().join("lib.jar");
+        let gbk = encoding_rs::GBK.encode(GBK_SAMPLE).0.into_owned();
+        jar_bytes(&jar_path, &[("p/EncodingSample.java", &gbk)]);
+        let loaded = read_entry(&jar_path, "p/EncodingSample.java", Some("gbk")).unwrap();
+        assert_eq!((loaded.text.as_str(), loaded.encoding.as_str()), (GBK_SAMPLE, "gbk"));
+        // An explicit encoding wins over detection, even when it decodes to replacement characters.
+        let forced = read_entry(&jar_path, "p/EncodingSample.java", Some("utf-8")).unwrap();
+        assert!(forced.text.contains('\u{FFFD}'));
+        assert_eq!(forced.encoding, "utf-8");
+        assert!(read_entry(&jar_path, "p/EncodingSample.java", Some("not-an-encoding")).is_none());
+    }
+
+    #[test]
+    fn class_sources_in_maven_caches_decode_non_utf8() {
+        let tmp = tempfile::tempdir().unwrap();
+        let m2 = tmp.path().join("m2/com/example/encoding-sample/1.0.0");
+        let gbk = encoding_rs::GBK.encode(GBK_SAMPLE).0.into_owned();
+        let facade = "@file:JvmName(\"SampleUtils\")\npackage example.encoding\n\n/** 中文注释。 */\nfun message() = \"中文编码测试：是否启用\"\n";
+        let facade_gbk = encoding_rs::GBK.encode(facade).0.into_owned();
+        jar(&m2.join("encoding-sample-1.0.0.jar"), &[]);
+        jar_bytes(
+            &m2.join("encoding-sample-1.0.0-sources.jar"),
+            &[("example/encoding/EncodingSample.java", &gbk), ("example/encoding/Renamed.kt", &facade_gbk)],
+        );
+        let uri = |class: &str| {
+            format!("jar://{}!/{class}", m2.join("encoding-sample-1.0.0.jar").to_string_lossy().replace('\\', "/"))
+        };
+        for (class, text) in
+            [("example/encoding/EncodingSample.class", GBK_SAMPLE), ("example/encoding/SampleUtils.class", facade)]
+        {
+            let (source_uri, loaded) = class_source(&uri(class), None).unwrap_or_else(|| panic!("{class}"));
+            assert!(
+                source_uri.ends_with("-sources.jar!/example/encoding/EncodingSample.java")
+                    || source_uri.ends_with("-sources.jar!/example/encoding/Renamed.kt")
+            );
+            assert_eq!(loaded.text, text, "{class}");
+            assert_eq!(loaded.encoding, "gbk", "{class}");
+            // The manually attached archive path decodes the same way.
+            let jdt = "jdt://contents/encoding-sample-1.0.0.jar/example.encoding/EncodingSample.class?=project/x";
+            let (_, attached) = source_in_archive(jdt, &m2.join("encoding-sample-1.0.0-sources.jar"), None).unwrap();
+            assert_eq!((attached.text.as_str(), attached.encoding.as_str()), (GBK_SAMPLE, "gbk"));
+        }
+        // Reload with an explicit encoding re-reads the same source.
+        let (_, reloaded) = class_source(&uri("example/encoding/EncodingSample.class"), Some("gbk")).unwrap();
+        assert_eq!((reloaded.text.as_str(), reloaded.encoding.as_str()), (GBK_SAMPLE, "gbk"));
     }
 
     #[test]

crates/ide-lsp/src/server.rs

@@ -148,6 +148,8 @@ pub struct Server {
     /// The instance whose just registered external project is loading, until an open file's
     /// diagnostics arrive (0: none).
     pub external_loading: std::sync::atomic::AtomicU64,
+    /// kotlin-lsp's project import as the current instance last reported it.
+    pub(crate) import_state: watch::Sender<Option<crate::kotlin_lsp::ImportState>>,
 }
 
 impl Server {
@@ -193,6 +195,7 @@ impl Server {
             external_diagnostics: std::sync::atomic::AtomicBool::new(false),
             external_refresh_queued: std::sync::atomic::AtomicBool::new(false),
             external_loading: std::sync::atomic::AtomicU64::new(0),
+            import_state: watch::channel(None).0,
         }
     }
 
@@ -249,10 +252,20 @@ impl Server {
         *self.started.lock() = Some(Instant::now());
         // A crash report quotes only this instance's output, not its predecessors'.
         self.stderr.lock().clear();
+        self.import_state.send_replace(None);
         self.phase.send_replace(Phase::Starting);
         Some(st.generation)
     }
 
+    /// Publishes instance `generation`'s import state unless a newer start replaced it; checked
+    /// under the state lock so it cannot land after [`Self::begin_start`]'s reset.
+    pub(crate) fn set_import_state(&self, generation: u64, state: crate::kotlin_lsp::ImportState) {
+        let st = self.state.lock();
+        if st.generation == generation {
+            self.import_state.send_replace(Some(state));
+        }
+    }
+
     /// Starting → Missing/Failed, publishing the status the failed start reports
     /// before waiters wake: a request that wakes on `Phase::Down` reads the status
     /// to say why it has no server, and must not still see `Starting`.

crates/ide-lsp/src/types.rs

@@ -357,6 +357,14 @@ pub struct VirtualDocument {
     pub description: Option<String>,
     /// Generated Java from a decompiler, rather than real source or a disassembler stub.
     pub decompiled: bool,
+    /// Charset the content was decoded with (a WHATWG label, e.g. `gbk`);
+    /// `utf-8` for text the server decoded itself.
+    pub encoding: String,
+    pub has_bom: bool,
+    /// "Reload with Encoding" can re-decode the origin's bytes (archive
+    /// entries, JDT sources with an editable attachment encoding); false for
+    /// server-generated content such as decompiled code.
+    pub can_reload_encoding: bool,
 }
 
 /// Reference updates for a file / folder move (`workspace/willRenameFiles`).

crates/ide-lsp/src/uri.rs

@@ -23,9 +23,20 @@ const PATH: &AsciiSet = &CONTROLS
     .add(b'}');
 
 pub fn path_to_uri_string(path: &Path) -> String {
-    let s = path.to_string_lossy();
-    let s = if cfg!(windows) { s.replace('\\', "/") } else { s.into_owned() };
+    let s = if cfg!(windows) {
+        dunce::simplified(path).to_string_lossy().replace('\\', "/")
+    } else {
+        path.to_string_lossy().into_owned()
+    };
     let mut out = String::from("file://");
+    // `\\server\share\p` → `file://server/share/p` (RFC 8089 Appendix E.3).
+    let unc = s.strip_prefix("//?/UNC/").or_else(|| s.strip_prefix("//")).filter(|_| cfg!(windows));
+    if let Some(unc) = unc {
+        let (host, rest) = unc.split_at(unc.find('/').unwrap_or(unc.len()));
+        out.extend(utf8_percent_encode(host, PATH));
+        out.extend(utf8_percent_encode(rest, PATH));
+        return out;
+    }
     if !s.starts_with('/') {
         out.push('/');
     }
@@ -41,21 +52,30 @@ pub fn path_to_uri(path: &Path) -> lsp_types::Uri {
     })
 }
 
-/// Converts a `file:` URI to a path; `None` for other schemes.
+/// Converts a `file:` URI to a path; `None` for other schemes. On Windows a
+/// host names a share (`file://server/share/p` → `\\server\share\p`) and the
+/// drive letter is upper-cased, as the rest of the IDE spells it.
 pub fn uri_to_path(uri: &str) -> Option<PathBuf> {
     let rest = uri.strip_prefix("file://").or_else(|| uri.strip_prefix("FILE://"))?;
-    // Skip an authority (`file://localhost/...`).
-    let path = match rest.find('/') {
-        Some(0) => rest,
-        Some(i) if rest[..i].eq_ignore_ascii_case("localhost") => &rest[i..],
-        _ => return None,
-    };
+    let (host, path) = rest.split_at(rest.find('/')?);
+    let local = host.is_empty() || host.eq_ignore_ascii_case("localhost");
     let path = path.split(['?', '#']).next().unwrap_or(path);
     let decoded = percent_decode_str(path).decode_utf8().ok()?;
     if cfg!(windows) {
+        if !local {
+            let host = percent_decode_str(host).decode_utf8().ok()?;
+            return Some(PathBuf::from(format!(r"\\{host}{}", decoded.replace('/', "\\"))));
+        }
         // `/C:/x` → `C:\x`
         let trimmed = decoded.strip_prefix('/').filter(|s| s.as_bytes().get(1) == Some(&b':')).unwrap_or(&decoded);
-        return Some(PathBuf::from(trimmed.replace('/', "\\")));
+        let mut path = trimmed.replace('/', "\\");
+        if path.as_bytes().get(1) == Some(&b':') {
+            path[..1].make_ascii_uppercase();
+        }
+        return Some(PathBuf::from(path));
+    }
+    if !local {
+        return None;
     }
     Some(PathBuf::from(decoded.into_owned()))
 }
@@ -89,6 +109,40 @@ mod tests {
         assert_eq!(uri_to_path("jdt://contents/x"), None);
     }
 
+    #[cfg(unix)]
+    #[test]
+    fn remote_hosts_are_not_local_paths() {
+        assert_eq!(uri_to_path("file://server/share/a.ts"), None);
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn windows_uris() {
+        for (uri, path) in [
+            ("file:///C:/a%20b/c.rs", r"C:\a b\c.rs"),
+            ("file:///c:/x/y.ts", r"C:\x\y.ts"),
+            ("file:///c%3A/x/y.ts", r"C:\x\y.ts"),
+            ("file:///C%3a/x", r"C:\x"),
+            ("file://localhost/d:/x", r"D:\x"),
+            ("file://server/share/a.ts", r"\\server\share\a.ts"),
+            ("file://server/share/a%20b/c.ts", r"\\server\share\a b\c.ts"),
+            ("file:////server/share/a.ts", r"\\server\share\a.ts"),
+        ] {
+            let got = uri_to_path(uri).unwrap();
+            assert_eq!(got.as_os_str(), path, "{uri}");
+        }
+        assert_eq!(uri_to_path("file://server"), None);
+        for (path, uri, back) in [
+            (r"C:\a b\c.rs", "file:///C:/a%20b/c.rs", r"C:\a b\c.rs"),
+            (r"\\?\C:\x\y.ts", "file:///C:/x/y.ts", r"C:\x\y.ts"),
+            (r"\\server\share\a b.ts", "file://server/share/a%20b.ts", r"\\server\share\a b.ts"),
+            (r"\\?\UNC\server\share\a.ts", "file://server/share/a.ts", r"\\server\share\a.ts"),
+        ] {
+            assert_eq!(path_to_uri(Path::new(path)).as_str(), uri, "{path}");
+            assert_eq!(uri_to_path(uri).unwrap().as_os_str(), back, "{path}");
+        }
+    }
+
     #[test]
     fn virtual_targets() {
         let jdt = "jdt://contents/rt.jar/java.lang/String.class?=p/%5C/x.jar%3Cjava.lang(String.class";

crates/ide-lsp/tests/mock_server.rs

@@ -7,7 +7,7 @@ use ide_core::{
 use ide_jsonrpc::{Handler, NoopHandler, Peer};
 use ide_language::{LanguageConfig, LanguageRegistry, LanguageServerConfig};
 use ide_lsp::types::*;
-use ide_lsp::{LaunchError, Launcher, LspManager};
+use ide_lsp::{KotlinDebugServer, KotlinDebugUnavailable, LaunchError, Launcher, LspManager};
 use ide_text::AppliedChange;
 use parking_lot::Mutex;
 use serde_json::{Value, json};
@@ -306,6 +306,7 @@ fn harness_configured(
         indent: None,
         ui_mode: None,
         framework_ui_modes: Vec::new(),
+        framework_files: Vec::new(),
         formatter: None,
         scratch_template: None,
         tree_sitter: None,
@@ -3211,6 +3212,33 @@ async fn rename_merges_the_servers_that_can_rename_there() {
     assert_eq!(edits_in(&edit, &html), [(rng(0, 3, 0, 8), "heading".into())]);
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn a_rename_the_server_withdraws_while_analysing_is_asked_again_then_explained() {
+    let h = harness(&[("dart", incremental_caps())]);
+    let (doc, path) = h.open("a.mk", "count = 1\n");
+    h.wait_status("dart", ServerStatus::Ready).await;
+    let dart = h.launcher.state("dart");
+    let r = json!({"start":{"line":0,"character":0},"end":{"line":0,"character":5}});
+    dart.respond("textDocument/rename", json!({ "changes": { uri_of(&path): [{ "range": r, "newText": "total" }] } }));
+    // Withdrawn while the server analyses an edit, then answered.
+    dart.errors.lock().insert("textDocument/rename".into(), (-32801, "Document was modified".into()));
+    let renaming = {
+        let mgr = h.mgr.clone();
+        tokio::spawn(async move { mgr.rename(doc, Pos::new(0, 1), "total".into(), Default::default()).await })
+    };
+    tokio::time::sleep(std::time::Duration::from_millis(400)).await;
+    dart.errors.lock().clear();
+    let edit = renaming.await.unwrap().unwrap().edit;
+    assert_eq!(edits_in(&edit, &path), [(rng(0, 0, 0, 5), "total".into())]);
+    assert!(dart.requested("textDocument/rename").len() >= 2);
+
+    // Withdrawn every time: an error that says so, not a silent cancellation.
+    dart.errors.lock().insert("textDocument/rename".into(), (-32801, "Document was modified".into()));
+    let err = h.mgr.rename(doc, Pos::new(0, 1), "total".into(), Default::default()).await.unwrap_err();
+    assert_ne!(err.kind, ide_core::error::ErrorKind::Cancelled);
+    assert!(err.message.contains("try again"), "{}", err.message);
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn angular_server_is_asked_about_typescript_only_in_component_templates() {
     let servers = [("vtsls", incremental_caps()), ("angular-language-server", incremental_caps())];
@@ -3641,6 +3669,340 @@ async fn jdt_class_file_contents() {
     assert_eq!(source.title, "WithSources.java");
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn jdt_library_sources_reload_with_the_attachment_encoding() {
+    let h = harness_for("java", "java", &[("jdtls", incremental_caps())], &[]);
+    h.open("App.java", "import example.encoding.EncodingSample;\n");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let s = h.launcher.state("jdtls");
+    let jdt = "jdt://contents/encoding-sample-1.0.jar/example.encoding/EncodingSample.class?=demo/%5C/m2%5C/encoding-sample-1.0.jar%3Cexample.encoding%28EncodingSample.class";
+
+    // The mock jdtls decodes the GBK attachment with the configured charset:
+    // until the encoding is updated, the text arrives garbled (U+FFFD).
+    let source = "package example.encoding;\n\n/** 中文编码测试。 */\npublic final class EncodingSample {}";
+    let garbled =
+        "package example.encoding;\n\n/** \u{FFFD}\u{FFFD}\u{FFFD}\u{FFFD} */\npublic final class EncodingSample {}";
+    let attachment_encoding: Arc<Mutex<Option<String>>> = Arc::default();
+    *s.responder.lock() = Some(Arc::new({
+        let encoding = attachment_encoding.clone();
+        move |_, method, params| match method {
+            "java/classFileContents" => {
+                let text = if encoding.lock().as_deref() == Some("gbk") { source } else { garbled };
+                Some(json!(text))
+            }
+            "workspace/executeCommand" => match params["command"].as_str()? {
+                "java.project.resolveSourceAttachment" => Some(json!({
+                    "errorMessage": null,
+                    "attributes": {
+                        "jarPath": "/m2/encoding-sample-1.0.jar",
+                        "sourceAttachmentPath": "/m2/encoding-sample-1.0-sources.jar",
+                        "sourceAttachmentEncoding": encoding.lock().clone(),
+                        "canEditEncoding": true,
+                    }
+                })),
+                "java.project.updateSourceAttachment" => {
+                    let attrs = &params["arguments"][0]["attributes"];
+                    *encoding.lock() = attrs["sourceAttachmentEncoding"].as_str().map(str::to_owned);
+                    Some(json!({ "errorMessage": null, "attributes": null }))
+                }
+                _ => None,
+            },
+            _ => None,
+        }
+    }));
+
+    let vd = h.mgr.virtual_document(jdt).await.unwrap();
+    assert_eq!(vd.text, garbled);
+    assert_eq!(vd.encoding, "utf-8", "no attachment encoding configured yet");
+    assert!(vd.can_reload_encoding);
+
+    let reloaded = h.mgr.reload_virtual(jdt, "gbk").await.unwrap();
+    assert_eq!(reloaded.text, source);
+    assert_eq!(reloaded.encoding, "gbk");
+    assert!(reloaded.can_reload_encoding);
+    // The update kept the attachment path (omitting it would drop the sources)
+    // and set the encoding; the contents were fetched again.
+    let updates: Vec<Value> = s
+        .requested("workspace/executeCommand")
+        .into_iter()
+        .filter(|p| p["command"] == "java.project.updateSourceAttachment")
+        .collect();
+    assert_eq!(updates.len(), 1);
+    assert_eq!(updates[0]["arguments"][0]["classFileUri"], jdt);
+    assert_eq!(updates[0]["arguments"][0]["attributes"]["sourceAttachmentPath"], "/m2/encoding-sample-1.0-sources.jar");
+    assert_eq!(updates[0]["arguments"][0]["attributes"]["sourceAttachmentEncoding"], "gbk");
+    assert!(s.requested("java/classFileContents").len() >= 2);
+    // The cache serves the re-decoded text without another round trip.
+    assert_eq!(h.mgr.virtual_document(jdt).await.unwrap().text, source);
+    // Round trip back to UTF-8.
+    let back = h.mgr.reload_virtual(jdt, "utf-8").await.unwrap();
+    assert_eq!(back.text, garbled);
+    assert_eq!(back.encoding, "utf-8");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn jdt_reload_waits_for_the_maven_container_refresh() {
+    let h = harness_for("java", "java", &[("jdtls", incremental_caps())], &[]);
+    h.open("App.java", "class App {}\n");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let s = h.launcher.state("jdtls");
+    let jdt = "jdt://contents/lib.jar/p/Lib.class?=demo/%5C/m2%5C/lib.jar%3Cp%28Lib.class";
+    // m2e persists and refreshes the container in a background job: resolve
+    // keeps reporting the old encoding for a few calls after the update.
+    let state: Arc<Mutex<(Option<String>, usize)>> = Arc::default();
+    *s.responder.lock() = Some(Arc::new({
+        let state = state.clone();
+        move |_, method, params| match method {
+            "java/classFileContents" => {
+                let enc = state.lock().0.clone();
+                Some(json!(if enc.as_deref() == Some("gbk") {
+                    "package p; /** 中文 */ class Lib {}"
+                } else {
+                    "package p; /** \u{FFFD} */ class Lib {}"
+                }))
+            }
+            "workspace/executeCommand" => match params["command"].as_str()? {
+                "java.project.resolveSourceAttachment" => {
+                    let mut st = state.lock();
+                    st.1 += 1;
+                    let reported = if st.1 > 2 { st.0.clone() } else { None };
+                    Some(json!({
+                        "attributes": {
+                            "sourceAttachmentPath": "/m2/lib-sources.jar",
+                            "sourceAttachmentEncoding": reported,
+                            "canEditEncoding": true,
+                        }
+                    }))
+                }
+                "java.project.updateSourceAttachment" => {
+                    let mut st = state.lock();
+                    st.0 = params["arguments"][0]["attributes"]["sourceAttachmentEncoding"].as_str().map(str::to_owned);
+                    st.1 = 0;
+                    Some(json!({ "errorMessage": null }))
+                }
+                _ => None,
+            },
+            _ => None,
+        }
+    }));
+    let vd = h.mgr.virtual_document(jdt).await.unwrap();
+    assert!(vd.text.contains('\u{FFFD}'));
+    let reloaded = h.mgr.reload_virtual(jdt, "gbk").await.unwrap();
+    assert_eq!(reloaded.text, "package p; /** 中文 */ class Lib {}");
+    assert_eq!(reloaded.encoding, "gbk");
+    assert!(state.lock().1 >= 3, "polled until the container reported the new encoding");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn jdt_reload_retries_when_a_restored_container_ignores_the_update() {
+    let h = harness_for("java", "java", &[("jdtls", incremental_caps())], &[]);
+    h.open("App.java", "class App {}\n");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let s = h.launcher.state("jdtls");
+    let jdt = "jdt://contents/lib.jar/p/Lib.class?=demo/%5C/m2%5C/lib.jar%3Cp%28Lib.class";
+    // jdtls replaces the encoding attribute by reference equality: an entry
+    // restored from the saved container state keeps the old value on the first
+    // update (a duplicate attribute is appended); only a second update, after
+    // the container was refreshed, applies the new one.
+    let state: Arc<Mutex<(Option<String>, usize)>> = Arc::default();
+    *s.responder.lock() = Some(Arc::new({
+        let state = state.clone();
+        move |_, method, params| match method {
+            "java/classFileContents" => {
+                let enc = state.lock().0.clone();
+                Some(json!(if enc.as_deref() == Some("gbk") {
+                    "package p; /** 中文 */ class Lib {}"
+                } else {
+                    "package p; /** \u{FFFD} */ class Lib {}"
+                }))
+            }
+            "workspace/executeCommand" => match params["command"].as_str()? {
+                "java.project.resolveSourceAttachment" => Some(json!({
+                    "attributes": {
+                        "sourceAttachmentPath": "/m2/lib-sources.jar",
+                        "sourceAttachmentEncoding": state.lock().0.clone(),
+                        "canEditEncoding": true,
+                    }
+                })),
+                "java.project.updateSourceAttachment" => {
+                    let mut st = state.lock();
+                    st.1 += 1;
+                    if st.1 > 1 {
+                        st.0 = params["arguments"][0]["attributes"]["sourceAttachmentEncoding"]
+                            .as_str()
+                            .map(str::to_owned);
+                    }
+                    Some(json!({ "errorMessage": null }))
+                }
+                _ => None,
+            },
+            _ => None,
+        }
+    }));
+    let vd = h.mgr.virtual_document(jdt).await.unwrap();
+    assert!(vd.text.contains('\u{FFFD}'));
+    let reloaded = h.mgr.reload_virtual(jdt, "gbk").await.unwrap();
+    assert_eq!(reloaded.text, "package p; /** 中文 */ class Lib {}");
+    assert_eq!(reloaded.encoding, "gbk");
+    let updates: Vec<Value> = s
+        .requested("workspace/executeCommand")
+        .into_iter()
+        .filter(|p| p["command"] == "java.project.updateSourceAttachment")
+        .collect();
+    assert_eq!(updates.len(), 2, "the ignored first update was retried once");
+    assert!(updates.iter().all(|u| u["arguments"][0]["attributes"]["sourceAttachmentPath"] == "/m2/lib-sources.jar"));
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn jdt_reload_reads_the_attachment_when_the_server_buffer_is_stale() {
+    use std::io::Write;
+    let tmp = tempfile::tempdir().unwrap();
+    let sources = tmp.path().join("lib-sources.jar");
+    let source = "package p; /** 中文 */ class Lib {}";
+    let gbk = encoding_rs::GBK.encode(source).0.into_owned();
+    let mut zip = zip::ZipWriter::new(std::fs::File::create(&sources).unwrap());
+    zip.start_file("p/Lib.java", zip::write::SimpleFileOptions::default()).unwrap();
+    zip.write_all(&gbk).unwrap();
+    zip.finish().unwrap();
+
+    let h = harness_for("java", "java", &[("jdtls", incremental_caps())], &[]);
+    h.open("App.java", "class App {}\n");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let s = h.launcher.state("jdtls");
+    let jdt = "jdt://contents/lib.jar/p/Lib.class?=demo/%5C/m2%5C/lib.jar%3Cp%28Lib.class";
+    // JDT caches the decoded buffer of a class file: even after the attachment
+    // encoding is updated, classFileContents keeps returning the old decoding.
+    let encoding: Arc<Mutex<Option<String>>> = Arc::default();
+    *s.responder.lock() = Some(Arc::new({
+        let encoding = encoding.clone();
+        let sources = sources.clone();
+        move |_, method, params| match method {
+            "java/classFileContents" => Some(json!("package p; /** \u{FFFD} */ class Lib {}")),
+            "workspace/executeCommand" => match params["command"].as_str()? {
+                "java.project.resolveSourceAttachment" => Some(json!({
+                    "attributes": {
+                        "sourceAttachmentPath": sources.to_string_lossy(),
+                        "sourceAttachmentEncoding": encoding.lock().clone(),
+                        "canEditEncoding": true,
+                    }
+                })),
+                "java.project.updateSourceAttachment" => {
+                    *encoding.lock() =
+                        params["arguments"][0]["attributes"]["sourceAttachmentEncoding"].as_str().map(str::to_owned);
+                    Some(json!({ "errorMessage": null }))
+                }
+                _ => None,
+            },
+            _ => None,
+        }
+    }));
+    let vd = h.mgr.virtual_document(jdt).await.unwrap();
+    assert!(vd.text.contains('\u{FFFD}'));
+    let reloaded = h.mgr.reload_virtual(jdt, "gbk").await.unwrap();
+    assert_eq!(reloaded.text, source, "read from the attachment, not the stale server buffer");
+    assert_eq!(reloaded.encoding, "gbk");
+    assert!(reloaded.can_reload_encoding);
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn jdt_reload_is_refused_when_the_sources_cannot_be_re_decoded() {
+    let h = harness_for("java", "java", &[("jdtls", incremental_caps())], &[]);
+    h.open("App.java", "class App {}\n");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let s = h.launcher.state("jdtls");
+    let class =
+        |name: &str| format!("jdt://contents/lib.jar/p/{name}.class?=demo/%5C/m2%5C/lib.jar%3Cp%28{name}.class");
+    s.respond("java/classFileContents", json!("package p;\npublic class Lib {}"));
+
+    // A container that does not allow editing the attachment encoding.
+    *s.responder.lock() = Some(Arc::new(|_, method, params| match method {
+        "workspace/executeCommand" if params["command"] == "java.project.resolveSourceAttachment" => Some(json!({
+            "attributes": { "sourceAttachmentPath": "/m2/lib-sources.jar", "canEditEncoding": false }
+        })),
+        _ => None,
+    }));
+    let vd = h.mgr.virtual_document(&class("ReadOnly")).await.unwrap();
+    assert!(!vd.can_reload_encoding);
+    let err = h.mgr.reload_virtual(&class("ReadOnly"), "gbk").await.unwrap_err();
+    assert!(err.message.contains("cannot be changed"), "{err}");
+
+    // Decompiled content has no attached sources to re-decode.
+    *s.responder.lock() = Some(Arc::new(|_, method, params| match method {
+        "workspace/executeCommand" if params["command"] == "java.project.resolveSourceAttachment" => Some(json!({
+            "attributes": { "sourceAttachmentPath": null, "canEditEncoding": true }
+        })),
+        _ => None,
+    }));
+    s.respond(
+        "java/classFileContents",
+        json!("// Source code is decompiled from a .class file using FernFlower decompiler (from Intellij IDEA).\npackage p;\npublic class Lib {}"),
+    );
+    let decompiled = h.mgr.virtual_document(&class("Decompiled")).await.unwrap();
+    assert!(decompiled.decompiled && !decompiled.can_reload_encoding);
+    let err = h.mgr.reload_virtual(&class("Decompiled"), "gbk").await.unwrap_err();
+    assert!(err.message.contains("no attached sources"), "{err}");
+
+    // The resolve command fails (unqueryable container): no reload offered.
+    s.errors.lock().insert("workspace/executeCommand".into(), (-32603, "unsupported".into()));
+    let unresolved = h.mgr.virtual_document(&class("Unresolved")).await.unwrap();
+    assert_eq!(unresolved.encoding, "utf-8");
+    assert!(!unresolved.can_reload_encoding);
+    let err = h.mgr.reload_virtual(&class("Unresolved"), "gbk").await.unwrap_err();
+    assert!(err.message.contains("cannot resolve"), "{err}");
+
+    // Server-generated content of other schemes cannot be re-decoded at all.
+    let err = h.mgr.reload_virtual("csharp:/p/App.csproj/decompiled/Lib.cs", "gbk").await.unwrap_err();
+    assert!(err.message.contains("generated by a language server"), "{err}");
+    // Unknown encodings are refused before any server round trip.
+    assert!(h.mgr.reload_virtual(&class("ReadOnly"), "not-an-encoding").await.is_err());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn jar_library_sources_reload_with_another_encoding() {
+    use std::io::Write;
+    let repo = tempfile::tempdir().unwrap();
+    let dir = repo.path().join("com/example/encoding-sample/1.0.0");
+    std::fs::create_dir_all(&dir).unwrap();
+    let source = "package example.encoding\n\n/** 中文编码测试。 */\nfun message() = \"中文编码测试：是否启用\"\n";
+    let gbk = encoding_rs::GBK.encode(source).0.into_owned();
+    let jar_bytes = |path: &Path, entries: &[(&str, &[u8])]| {
+        let mut zip = zip::ZipWriter::new(std::fs::File::create(path).unwrap());
+        for (name, bytes) in entries {
+            zip.start_file(*name, zip::write::SimpleFileOptions::default()).unwrap();
+            zip.write_all(bytes).unwrap();
+        }
+        zip.finish().unwrap();
+    };
+    jar_bytes(&dir.join("encoding-sample-1.0.jar"), &[("example/encoding/EncodingSampleKt.class", b"\0")]);
+    jar_bytes(&dir.join("encoding-sample-1.0-sources.jar"), &[("example/encoding/EncodingSample.kt", &gbk)]);
+    let jar_uri = |jar: &Path, entry: &str| format!("jar://{}!/{entry}", uri_of(jar).trim_start_matches("file://"));
+
+    let h = harness_for("kotlin", "kt", &[("kotlin-lsp", incremental_caps())], &[]);
+    h.open("Main.kt", "fun main() {}\n");
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    let class = jar_uri(&dir.join("encoding-sample-1.0.jar"), "example/encoding/EncodingSampleKt.class");
+    let entry = jar_uri(&dir.join("encoding-sample-1.0-sources.jar"), "example/encoding/EncodingSample.kt");
+
+    let vd = h.mgr.virtual_document(&class).await.unwrap();
+    assert_eq!(vd.text, source);
+    assert_eq!(vd.encoding, "gbk");
+    assert!(vd.can_reload_encoding);
+    // An explicit encoding wins over detection, even when it garbles the text.
+    let forced = h.mgr.reload_virtual(&class, "utf-8").await.unwrap();
+    assert!(forced.text.contains('\u{FFFD}'));
+    assert_eq!(forced.encoding, "utf-8");
+    let back = h.mgr.reload_virtual(&class, "gbk").await.unwrap();
+    assert_eq!((back.text.as_str(), back.encoding.as_str()), (source, "gbk"));
+    // Non-class entries reload the same way.
+    let entry_vd = h.mgr.virtual_document(&entry).await.unwrap();
+    assert_eq!((entry_vd.text.as_str(), entry_vd.encoding.as_str()), (source, "gbk"));
+    let entry_reload = h.mgr.reload_virtual(&entry, "gbk").await.unwrap();
+    assert_eq!(entry_reload.text, source);
+    // Missing sources fail cleanly.
+    let missing = jar_uri(&dir.join("encoding-sample-1.0.jar"), "example/encoding/Missing.class");
+    assert!(h.mgr.reload_virtual(&missing, "gbk").await.is_err());
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn class_file_opening_routes_sources_and_binary_documents() {
     let mut caps = incremental_caps();
@@ -5963,6 +6325,208 @@ async fn hierarchy_refactorings_name_the_servers_without_them() {
     assert_eq!(e.message, "plain doesn't support Pull Members Up");
 }
 
+// ------------------------------------------------------------------ kotlin-lsp debug server
+
+type KotlinDebug = Result<KotlinDebugServer, KotlinDebugUnavailable>;
+
+fn kotlin_lsp_harness() -> (Harness, Arc<MockState>) {
+    let h = harness_for("kotlin", "kt", &[("kotlin-lsp", incremental_caps())], &[]);
+    let s = h.launcher.state("kotlin-lsp");
+    s.respond("workspace/executeCommand", json!(4711));
+    (h, s)
+}
+
+fn spawn_kotlin_debug_server(
+    h: &Harness,
+    path: &Path,
+    import_wait: Duration,
+    cancel: &CancellationToken,
+) -> tokio::task::JoinHandle<KotlinDebug> {
+    let (mgr, path, cancel) = (h.mgr.clone(), path.to_owned(), cancel.clone());
+    tokio::spawn(async move { mgr.kotlin_debug_server(&path, import_wait, &cancel).await })
+}
+
+async fn joined(debug: tokio::task::JoinHandle<KotlinDebug>) -> KotlinDebug {
+    tokio::time::timeout(Duration::from_secs(10), debug).await.expect("kotlin_debug_server returned").unwrap()
+}
+
+fn import_progress(s: &MockState, value: Value) {
+    s.peer().notify("$/progress", json!({ "token": "import", "value": value })).unwrap();
+}
+
+fn import_finished(s: &MockState, folders: &[(&Path, &str)]) {
+    let folders: Vec<Value> = folders
+        .iter()
+        .map(|(dir, status)| json!({ "folderUri": format!("{}/", uri_of(dir)), "tool": "gradle", "status": status }))
+        .collect();
+    s.peer().notify("intellij/workspaceImportState", json!({ "phase": "FINISHED", "folders": folders })).unwrap();
+}
+
+fn debug_server_requests(s: &MockState) -> Vec<Value> {
+    s.requested("workspace/executeCommand")
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn waits_for_the_import_before_starting_the_debug_server() {
+    // kotlin-lsp sends the progress end and FINISHED within the same millisecond, in either order.
+    for finished_first in [false, true] {
+        let (h, s) = kotlin_lsp_harness();
+        let main = h.root.join("Main.kt");
+        std::fs::write(&main, "fun main() {}").unwrap();
+        let debug = spawn_kotlin_debug_server(&h, &main, Duration::from_secs(10), &CancellationToken::new());
+        h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+        // Repeats every few seconds while the project stays usable: never waited for.
+        s.peer()
+            .notify("$/progress", json!({ "token": "index", "value": { "kind": "begin", "title": "Indexing" } }))
+            .unwrap();
+        import_progress(&s, json!({ "kind": "begin", "title": "Importing" }));
+        h.wait_status("kotlin-lsp", ServerStatus::Busy).await;
+        tokio::time::sleep(Duration::from_millis(300)).await;
+        assert!(debug_server_requests(&s).is_empty(), "started while importing");
+
+        if finished_first {
+            import_finished(&s, &[(&h.root, "SUCCESS")]);
+            tokio::time::sleep(Duration::from_millis(200)).await;
+            assert!(debug_server_requests(&s).is_empty(), "started while the Importing task runs");
+            import_progress(&s, json!({ "kind": "end" }));
+        } else {
+            import_progress(&s, json!({ "kind": "end" }));
+            tokio::time::sleep(Duration::from_millis(200)).await;
+            assert!(debug_server_requests(&s).is_empty(), "started before FINISHED");
+            import_finished(&s, &[(&h.root, "SUCCESS")]);
+        }
+
+        assert_eq!(joined(debug).await, Ok(KotlinDebugServer { port: 4711, root: h.root.clone() }));
+        assert_eq!(
+            debug_server_requests(&s),
+            vec![json!({ "command": "start_debug_server", "arguments": [uri_of(&h.root)] })],
+            "finished_first: {finished_first}"
+        );
+    }
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn still_importing_after_the_wait_is_reported() {
+    let (h, s) = kotlin_lsp_harness();
+    let r = h.mgr.kotlin_debug_server(&h.root, Duration::from_millis(200), &CancellationToken::new()).await;
+    assert_eq!(r, Err(KotlinDebugUnavailable::StillImporting));
+    assert!(debug_server_requests(&s).is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn cancelling_the_import_wait_reports_still_importing() {
+    let (h, s) = kotlin_lsp_harness();
+    let cancel = CancellationToken::new();
+    let debug = spawn_kotlin_debug_server(&h, &h.root, Duration::from_secs(60), &cancel);
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    tokio::time::sleep(Duration::from_millis(100)).await;
+    assert!(!debug.is_finished());
+    cancel.cancel();
+    assert_eq!(joined(debug).await, Err(KotlinDebugUnavailable::StillImporting));
+    assert!(debug_server_requests(&s).is_empty());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_failed_import_of_the_module_is_reported() {
+    // Another module that failed does not keep this one from debugging.
+    for other_module_failed in [false, true] {
+        let (h, s) = kotlin_lsp_harness();
+        let main = h.root.join("app/Main.kt");
+        let debug = spawn_kotlin_debug_server(&h, &main, Duration::from_secs(10), &CancellationToken::new());
+        h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+        let lib = h.root.join("lib");
+        let (folders, expected) = if other_module_failed {
+            (
+                vec![(h.root.as_path(), "SUCCESS"), (lib.as_path(), "FAILED")],
+                Ok(KotlinDebugServer { port: 4711, root: h.root.clone() }),
+            )
+        } else {
+            (vec![(h.root.as_path(), "FAILED")], Err(KotlinDebugUnavailable::ImportFailed))
+        };
+        import_finished(&s, &folders);
+        assert_eq!(joined(debug).await, expected, "other_module_failed: {other_module_failed}");
+    }
+}
+
+#[cfg(unix)]
+#[tokio::test(flavor = "multi_thread")]
+async fn a_failed_import_is_reported_through_a_symlinked_root() {
+    // The debugged path names the root through a symlink, the folder URI names its target,
+    // and the file does not exist yet.
+    let (h, s) = kotlin_lsp_harness();
+    let links = tempfile::tempdir().unwrap();
+    let link = links.path().join("project");
+    std::os::unix::fs::symlink(&h.root, &link).unwrap();
+    let debug =
+        spawn_kotlin_debug_server(&h, &link.join("app/Main.kt"), Duration::from_secs(10), &CancellationToken::new());
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    import_finished(&s, &[(&h.root, "FAILED")]);
+    assert_eq!(joined(debug).await, Err(KotlinDebugUnavailable::ImportFailed));
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn an_older_finished_import_does_not_count_after_a_restart() {
+    let (h, s) = kotlin_lsp_harness();
+    let debug = spawn_kotlin_debug_server(&h, &h.root, Duration::from_secs(10), &CancellationToken::new());
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    import_finished(&s, &[(&h.root, "SUCCESS")]);
+    assert!(joined(debug).await.is_ok());
+
+    let id = h.mgr.servers()[0].id;
+    h.mgr.restart(id).await.unwrap();
+    let r = h.mgr.kotlin_debug_server(&h.root, Duration::from_millis(300), &CancellationToken::new()).await;
+    assert_eq!(r, Err(KotlinDebugUnavailable::StillImporting));
+    assert_eq!(debug_server_requests(&s).len(), 1);
+
+    let debug = spawn_kotlin_debug_server(&h, &h.root, Duration::from_secs(10), &CancellationToken::new());
+    import_finished(&s, &[(&h.root, "SUCCESS")]);
+    assert_eq!(joined(debug).await, Ok(KotlinDebugServer { port: 4711, root: h.root.clone() }));
+    assert_eq!(debug_server_requests(&s).len(), 2);
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn without_kotlin_lsp_the_reason_is_not_configured() {
+    let wait = Duration::from_secs(1);
+    let cancel = CancellationToken::new();
+    let h = harness_for("kotlin", "kt", &[("kotlin-language-server", incremental_caps())], &[]);
+    assert_eq!(h.mgr.kotlin_debug_server(&h.root, wait, &cancel).await, Err(KotlinDebugUnavailable::NotConfigured));
+
+    let (h, s) = kotlin_lsp_harness();
+    s.missing.store(true, Ordering::SeqCst);
+    assert_eq!(h.mgr.kotlin_debug_server(&h.root, wait, &cancel).await, Err(KotlinDebugUnavailable::NotInstalled));
+
+    let (h, _) = kotlin_lsp_harness();
+    h.mgr.set_config_hook(Box::new(|cfg, _| cfg.launch_error = Some("needs JDK 21".into())));
+    assert_eq!(
+        h.mgr.kotlin_debug_server(&h.root, wait, &cancel).await,
+        Err(KotlinDebugUnavailable::NotStarted("needs JDK 21".into()))
+    );
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn a_debug_server_error_is_reported() {
+    let (h, s) = kotlin_lsp_harness();
+    s.errors.lock().insert("workspace/executeCommand".into(), (-32603, "boom".into()));
+    let debug = spawn_kotlin_debug_server(&h, &h.root, Duration::from_secs(10), &CancellationToken::new());
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    import_finished(&s, &[(&h.root, "SUCCESS")]);
+    match joined(debug).await {
+        Err(KotlinDebugUnavailable::Failed(m)) => assert!(m.contains("boom"), "{m}"),
+        other => panic!("{other:?}"),
+    }
+
+    s.errors.lock().clear();
+    for port in [json!(0), json!(65536), json!("4711"), Value::Null] {
+        s.respond("workspace/executeCommand", port.clone());
+        match h.mgr.kotlin_debug_server(&h.root, Duration::from_secs(1), &CancellationToken::new()).await {
+            Err(KotlinDebugUnavailable::Failed(m)) => {
+                assert_eq!(m, format!("unexpected debug server port: {port}"))
+            }
+            other => panic!("{port}: {other:?}"),
+        }
+    }
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn injected_documents_route_and_resolve_without_exposing_virtual_files() {
     for encoding in ["utf-16", "utf-8"] {
@@ -6151,3 +6715,69 @@ async fn missing_injected_server_uses_the_normal_single_install_notification() {
     h.mgr.did_close(host);
     h.mgr.shutdown_all().await;
 }
+
+/// #2248: `go.mod` files are served by gopls with the language id it
+/// understands, and its pushed diagnostics reach the Problems view.
+#[tokio::test(flavor = "multi_thread")]
+async fn gomod_files_are_served_by_gopls() {
+    let dir = tempfile::tempdir().unwrap();
+    let root = dunce::canonicalize(dir.path()).unwrap();
+    let registry = Arc::new(LanguageRegistry::load(None).unwrap());
+    // The bundled configs route Go files of every kind to gopls.
+    for lang in ["go", "go.mod", "go.work"] {
+        let cfg = registry.get(&LanguageId::new(lang)).unwrap_or_else(|| panic!("{lang} has no language definition"));
+        assert!(cfg.language_servers.iter().any(|s| s.name == "gopls"), "{lang} is not served by gopls");
+    }
+    let launcher = Arc::new(MockLauncher::default());
+    *launcher.state("gopls").caps.lock() = incremental_caps();
+    let events = Arc::new(Mutex::new(Vec::new()));
+    let sink = {
+        let events = events.clone();
+        Arc::new(move |e: IdeEvent| events.lock().push(e))
+    };
+    let mgr = LspManager::with_launcher(root.clone(), registry, sink, launcher.clone());
+    let text = "module example.com/app\n\ngo 1.22\n";
+    let path = root.join("go.mod");
+    std::fs::write(&path, text).unwrap();
+    assert!(mgr.serves_path(&path));
+    mgr.did_open(DocId::next(), &path, &LanguageId::new("go.mod"), 1, text);
+    let gopls = launcher.state("gopls");
+    eventually(|| !gopls.notified("textDocument/didOpen").is_empty()).await;
+    // gopls only treats the file as a module file for the `go.mod` id.
+    let opened = &gopls.notified("textDocument/didOpen")[0]["textDocument"];
+    assert_eq!(opened["languageId"], json!("go.mod"));
+    // The module root (the go.mod itself is the marker) scopes the server.
+    let init = &gopls.requested("initialize")[0];
+    assert_eq!(init["rootUri"], json!(uri_of(&root)));
+    // Same startup options as when a `.go` file launches the server first.
+    assert_eq!(init["initializationOptions"]["semanticTokens"], json!(true));
+    // Pushed go.mod diagnostics surface with gopls as their source.
+    gopls
+        .peer()
+        .notify(
+            "textDocument/publishDiagnostics",
+            json!({ "uri": uri_of(&path), "diagnostics": [{
+                "range": {"start": {"line": 2, "character": 3}, "end": {"line": 2, "character": 7}},
+                "severity": 1, "message": "missing requirement", "source": "gopls" }] }),
+        )
+        .unwrap();
+    eventually(|| {
+        events
+            .lock()
+            .iter()
+            .any(|e| matches!(e, IdeEvent::Diagnostics { path: p, source, .. } if p.0 == path && source == "gopls"))
+    })
+    .await;
+    let items = events
+        .lock()
+        .iter()
+        .filter_map(|e| match e {
+            IdeEvent::Diagnostics { path: p, items, .. } if p.0 == path => Some(items.clone()),
+            _ => None,
+        })
+        .next_back()
+        .unwrap();
+    assert_eq!(items.len(), 1);
+    assert_eq!(items[0].message, "missing requirement");
+    mgr.shutdown_all().await;
+}

crates/ide-lsp/tests/real_servers.rs

@@ -55,6 +55,7 @@ fn lang(id: &str, ext: &str, server: LanguageServerConfig) -> LanguageConfig {
         indent: None,
         ui_mode: None,
         framework_ui_modes: Vec::new(),
+        framework_files: Vec::new(),
         formatter: None,
         scratch_template: None,
         tree_sitter: None,

crates/ide-remote/src/deploy.rs

@@ -69,7 +69,7 @@ pub struct TransferError {
 }
 
 impl TransferReport {
-    fn fail(&mut self, path: impl Into<String>, e: IdeError) {
+    pub(crate) fn fail(&mut self, path: impl Into<String>, e: IdeError) {
         self.errors.push(TransferError { path: path.into(), message: e.message });
     }
 }

crates/ide-remote/src/service.rs

@@ -286,6 +286,70 @@ impl RemoteService {
         r
     }
 
+    /// Remote Host › Download to…: `remotes` (folders recursively) into the local folder `dir`,
+    /// each under its own name, without the server path above it. Existing files are replaced.
+    pub async fn download_into(
+        &self,
+        connection: &FsConnection,
+        remotes: &[String],
+        dir: &Path,
+        cancel: &CancellationToken,
+        progress: &mut (dyn FnMut(&str, usize, usize) + Send),
+    ) -> IdeResult<TransferReport> {
+        let fs = self.fs(connection).await?;
+        let mut report = TransferReport::default();
+        let mut folders = Vec::new();
+        let mut jobs = Vec::new();
+        for remote in remotes {
+            let Some(top) = download_target(dir, remote, remote) else {
+                report.skipped += 1;
+                continue;
+            };
+            match fs.stat(remote).await {
+                Ok(Some(e)) if e.is_dir => {
+                    folders.push(top);
+                    let mut entries = Vec::new();
+                    if let Err(e) = remote_tree(&fs, remote, cancel, &mut entries).await {
+                        report.fail(remote.clone(), e);
+                    }
+                    for entry in entries {
+                        match download_target(dir, remote, &entry.path) {
+                            Some(local) if entry.is_dir => folders.push(local),
+                            Some(local) => jobs.push((entry.path, local)),
+                            None => report.skipped += 1,
+                        }
+                    }
+                }
+                Ok(Some(_)) => jobs.push((remote.clone(), top)),
+                Ok(None) => report.fail(remote.clone(), IdeError::not_found(format!("{remote} does not exist"))),
+                Err(e) => report.fail(remote.clone(), e),
+            }
+        }
+        for folder in &folders {
+            if let Err(e) = tokio::fs::create_dir_all(folder).await {
+                report.fail(folder.display().to_string(), e.into());
+            }
+        }
+        for (i, (remote, local)) in jobs.iter().enumerate() {
+            if cancel.is_cancelled() {
+                break;
+            }
+            progress(remote, i, jobs.len());
+            if let Some(parent) = local.parent()
+                && let Err(e) = tokio::fs::create_dir_all(parent).await
+            {
+                report.fail(remote.clone(), e.into());
+                continue;
+            }
+            match fs.download(remote, local).await {
+                Ok(()) => report.files += 1,
+                Err(e) => report.fail(remote.clone(), e),
+            }
+        }
+        fs.close().await;
+        Ok(report)
+    }
+
     // --- save hook -----------------------------------------------------------------
 
     /// After a document save: uploads a remote file's copy, or (automatic upload)
@@ -497,3 +561,70 @@ fn cache_key(connection: &FsConnection) -> String {
         FsConnection::Sftp { ssh } => format!("sftp-{ssh}"),
     }
 }
+
+/// Files and folders under remote folder `dir` (symlinked folders are not followed).
+async fn remote_tree(
+    fs: &RemoteFs,
+    dir: &str,
+    cancel: &CancellationToken,
+    out: &mut Vec<RemoteEntry>,
+) -> IdeResult<()> {
+    for e in fs.list(dir).await? {
+        if cancel.is_cancelled() {
+            return Err(IdeError::cancelled());
+        }
+        let descend = e.is_dir && !e.is_symlink;
+        let path = e.path.clone();
+        out.push(e);
+        if descend {
+            Box::pin(remote_tree(fs, &path, cancel, out)).await?;
+        }
+    }
+    Ok(())
+}
+
+/// Where remote `path`, inside the downloaded `selected` file or folder, lands under local `dir`:
+/// `dir/<name of selected>/<rest>`. `None` for a name that would leave `dir`.
+fn download_target(dir: &Path, selected: &str, path: &str) -> Option<PathBuf> {
+    let selected = selected.trim_end_matches('/');
+    let name = selected.rsplit('/').next()?;
+    let rest = path.trim_end_matches('/').strip_prefix(selected)?;
+    if !rest.is_empty() && !rest.starts_with('/') {
+        return None;
+    }
+    let mut local = dir.to_path_buf();
+    for part in std::iter::once(name).chain(rest.split('/').filter(|p| !p.is_empty())) {
+        if matches!(part, "" | "." | "..") || part.contains('\\') || (cfg!(windows) && part.contains(':')) {
+            return None;
+        }
+        local.push(part);
+    }
+    Some(local)
+}
+
+#[cfg(test)]
+mod download_into_tests {
+    use super::*;
+
+    #[test]
+    fn downloads_keep_only_the_selected_name() {
+        let dir = Path::new("/p/project");
+        let selected = "/home/u/www/site/current/drush";
+        assert_eq!(download_target(dir, selected, selected), Some(dir.join("drush")));
+        assert_eq!(download_target(dir, "/home/u/www/site/current/drush/", selected), Some(dir.join("drush")));
+        assert_eq!(
+            download_target(dir, selected, "/home/u/www/site/current/drush/src/a.php"),
+            Some(dir.join("drush").join("src").join("a.php"))
+        );
+        assert_eq!(download_target(dir, "/srv/app.log", "/srv/app.log"), Some(dir.join("app.log")));
+    }
+
+    #[test]
+    fn names_that_would_leave_the_folder_are_refused() {
+        let dir = Path::new("/p/project");
+        assert_eq!(download_target(dir, "/srv/a", "/srv/a/../../etc/passwd"), None);
+        assert_eq!(download_target(dir, "/srv/a", "/srv/ab/x"), None, "a sibling with the same prefix");
+        assert_eq!(download_target(dir, "/", "/etc"), None, "the root has no name");
+        assert_eq!(download_target(dir, "/srv/..", "/srv/.."), None);
+    }
+}

crates/ide-remote/tests/local.rs

@@ -319,3 +319,37 @@ async fn browser_mappings_resolve_symlinks_and_download_to_the_project() {
     assert!(report.errors.is_empty());
     assert_eq!(std::fs::read_to_string(local).unwrap(), "from the server");
 }
+
+#[tokio::test]
+async fn download_into_copies_only_the_selected_items() {
+    let tmp = tempfile::tempdir().unwrap();
+    let server = tmp.path().join("srv/www/site/current");
+    let project = tmp.path().join("project");
+    std::fs::create_dir_all(server.join("drush/sub")).unwrap();
+    std::fs::create_dir_all(server.join("drush/empty")).unwrap();
+    std::fs::create_dir_all(&project).unwrap();
+    std::fs::write(server.join("drush/a.txt"), "a").unwrap();
+    std::fs::write(server.join("drush/sub/b.txt"), "b").unwrap();
+    std::fs::write(server.join("index.php"), "php").unwrap();
+    std::fs::write(project.join("index.php"), "old").unwrap();
+    let service = service(tmp.path());
+    let remotes = [server.join("drush"), server.join("index.php")].map(|p| p.to_str().unwrap().to_owned());
+    let report = service
+        .download_into(&FsConnection::Local, &remotes, &project, &CancellationToken::new(), &mut |_, _, _| {})
+        .await
+        .unwrap();
+    assert_eq!(report.files, 3, "{report:?}");
+    assert!(report.errors.is_empty(), "{report:?}");
+    assert_eq!(std::fs::read_to_string(project.join("drush/a.txt")).unwrap(), "a");
+    assert_eq!(std::fs::read_to_string(project.join("drush/sub/b.txt")).unwrap(), "b");
+    assert!(project.join("drush/empty").is_dir());
+    assert_eq!(std::fs::read_to_string(project.join("index.php")).unwrap(), "php");
+    assert!(!project.join("srv").exists() && !project.join("www").exists());
+
+    let missing = [server.join("gone").to_str().unwrap().to_owned()];
+    let report = service
+        .download_into(&FsConnection::Local, &missing, &project, &CancellationToken::new(), &mut |_, _, _| {})
+        .await
+        .unwrap();
+    assert_eq!((report.files, report.errors.len()), (0, 1), "{report:?}");
+}

crates/ide-run/src/tomcat.rs

@@ -863,6 +863,48 @@ fn module_dir(root: &Path, module: Option<&Path>) -> PathBuf {
     }
 }
 
+/// The module directory a Tomcat config's WAR belongs to. Created configs carry it as `cwd`
+/// (set from the selected artifact); when it is missing, the selected artifact id still names
+/// the module — `maven:<pom>` its POM, `gradle:…` its build — instead of falling back to the
+/// project root, whose own `src` rarely exists and would make every launch look current.
+fn artifact_module_dir(root: &Path, config: &RunConfig) -> PathBuf {
+    if config.cwd.is_some() {
+        return module_dir(root, config.cwd.as_ref().map(|c| c.0.as_path()));
+    }
+    let selected = config.extras.params.get("artifact").filter(|s| !s.is_empty());
+    if let Some(id) = selected {
+        if let Some(pom) = id.strip_prefix("maven:") {
+            // `maven:pom.xml` is the root module itself.
+            return match Path::new(pom).parent().filter(|p| !p.as_os_str().is_empty()) {
+                Some(dir) => root.join(dir),
+                None => root.to_path_buf(),
+            };
+        }
+        if let Some(rest) = id.strip_prefix("gradle:") {
+            // `gradle:<project path>` for the root build, else `gradle:["<build dir>", "<path>"]`.
+            if let Ok((dir, path)) = serde_json::from_str::<(String, String)>(rest) {
+                return root.join(gradle_module_dir(&dir, &path));
+            }
+            if !rest.trim_matches(':').is_empty() {
+                return root.join(gradle_module_dir("", rest));
+            }
+        }
+    }
+    root.to_path_buf()
+}
+
+/// Maps a Gradle project path (`:` for the build itself, `:web` for a subproject) below its
+/// build directory. Custom `projectDir` mappings are invisible here, so this is the
+/// conventional layout; still closer than the project root.
+fn gradle_module_dir(dir: &str, path: &str) -> PathBuf {
+    let mut module = PathBuf::from(dir);
+    let rel = path.trim_start_matches(':').replace(':', "/");
+    if !rel.is_empty() {
+        module.push(rel);
+    }
+    module
+}
+
 /// The newest modification time of `path` or, for a directory, anything below it.
 fn newest_mtime_under(path: &Path) -> Option<std::time::SystemTime> {
     let meta = fs::metadata(path).ok()?;
@@ -902,14 +944,16 @@ fn find_built_war(root: &Path, module: Option<&Path>) -> Option<PathBuf> {
 
 /// Whether the WAR a Tomcat config deploys is newer than the module's sources, so its
 /// "Before launch › Build" task can be skipped (IDEA's up-to-date check). Conservative:
-/// a missing WAR or a newer source/build file means it is not current. Only the module's
-/// own sources and build files are inspected, not dependency modules.
-pub fn artifact_is_current(root: &Path, base: &Path, config: &RunConfig) -> bool {
+/// a missing WAR or a newer source/build file means it is not current. Besides the WAR
+/// module's sources, web resources and build files, the sources and build files of every
+/// module in `modules` (project-relative build modules) are inspected: a mapper XML or
+/// class in a module the WAR depends on is packaged into it as a JAR.
+pub fn artifact_is_current(root: &Path, base: &Path, config: &RunConfig, modules: &[PathBuf]) -> bool {
     let p = &config.extras.params;
     if p.get("deployment").map(String::as_str).unwrap_or("artifact") != "artifact" {
         return true;
     }
-    let module = module_dir(root, config.cwd.as_ref().map(|c| c.0.as_path()));
+    let module = artifact_module_dir(root, config);
     let selected = p.get("artifact").filter(|s| !s.is_empty());
     let recorded_id = fs::read_to_string(base.join("artifact-id.txt")).ok();
     let id_matches = selected.is_none_or(|id| recorded_id.as_deref().map(str::trim) == Some(id.as_str()));
@@ -923,7 +967,24 @@ pub fn artifact_is_current(root: &Path, base: &Path, config: &RunConfig) -> bool
     };
     let Ok(war_time) = fs::metadata(&war).and_then(|m| m.modified()) else { return false };
     let mut newest = newest_mtime_under(&module.join("src"));
-    for dir in [module.as_path(), root] {
+    // Web content packaged from outside `src` (a custom `warSourceDirectory`, `webResources`
+    // directories, a custom Gradle web app dir) also lands in the WAR — the running-session
+    // sync copies it from these same folders — so a save there must rebuild too (#2685).
+    for (dir, _) in web_sources(&module) {
+        if let Some(time) = newest_mtime_under(&dir)
+            && newest.is_none_or(|cur| time > cur)
+        {
+            newest = Some(time);
+        }
+    }
+    let other_modules = modules.iter().map(|m| root.join(m));
+    for dir in [module.clone(), root.to_path_buf()].into_iter().chain(other_modules) {
+        if dir != module
+            && let Some(time) = newest_mtime_under(&dir.join("src"))
+            && newest.is_none_or(|cur| time > cur)
+        {
+            newest = Some(time);
+        }
         for name in ["pom.xml", "build.gradle", "build.gradle.kts"] {
             if let Ok(time) = fs::metadata(dir.join(name)).and_then(|m| m.modified())
                 && newest.is_none_or(|cur| time > cur)
@@ -946,6 +1007,7 @@ pub fn deployment(root: &Path, base: &Path, config: &RunConfig, resources_only:
             let recorded_id = fs::read_to_string(base.join("artifact-id.txt")).ok();
             let id_matches = selected.is_none_or(|id| recorded_id.as_deref().map(str::trim) == Some(id.as_str()));
             let recorded = fs::read_to_string(base.join("artifact-path.txt")).ok().map(|s| PathBuf::from(s.trim()));
+            let module = artifact_module_dir(root, config);
             let war = match recorded.filter(|_| id_matches) {
                 Some(war) => {
                     if war.is_file() && is_war(&war) {
@@ -954,7 +1016,7 @@ pub fn deployment(root: &Path, base: &Path, config: &RunConfig, resources_only:
                         return Err(invalid(format!("The built WAR artifact does not exist: {}", war.display())));
                     }
                 }
-                None => find_built_war(root, config.cwd.as_ref().map(|c| c.0.as_path())).ok_or_else(|| {
+                None => find_built_war(root, Some(module.as_path())).ok_or_else(|| {
                     invalid("No built WAR artifact found - build the project first, or add 'Build' to Before launch")
                 })?,
             };
@@ -1592,10 +1654,119 @@ mod tests {
         c.cwd = Some(ide_core::IpcPath(PathBuf::from("web")));
         c.extras.params.insert("artifact".into(), "maven:web/pom.xml".into());
         // The WAR was packed after the source was written.
-        assert!(artifact_is_current(root, &base, &c));
+        assert!(artifact_is_current(root, &base, &c, &[]));
         std::thread::sleep(std::time::Duration::from_millis(20));
         fs::write(&source, "class App { int changed; }").unwrap();
-        assert!(!artifact_is_current(root, &base, &c));
+        assert!(!artifact_is_current(root, &base, &c, &[]));
+    }
+
+    #[test]
+    fn up_to_date_check_follows_the_selected_artifact_when_cwd_is_missing() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let module = root.join("web");
+        fs::create_dir_all(module.join("src/main/resources")).unwrap();
+        fs::create_dir_all(module.join("target")).unwrap();
+        fs::write(root.join("pom.xml"), "<project/>").unwrap();
+        fs::write(module.join("pom.xml"), "<project/>").unwrap();
+        let source = module.join("src/main/resources/applicationContext.xml");
+        fs::write(&source, "<beans/>").unwrap();
+        let war = module.join("target/app.war");
+        archive(&war, &[("WEB-INF/web.xml", "<web-app/>")]);
+        let base = root.join("cache");
+        fs::create_dir_all(&base).unwrap();
+        // A previous IDE build recorded its archive, as `ide_build::web::build` leaves behind.
+        fs::write(base.join("artifact-id.txt"), "maven:web/pom.xml").unwrap();
+        fs::write(base.join("artifact-path.txt"), war.to_string_lossy().as_bytes()).unwrap();
+        // Older configs may not carry the artifact's module as `cwd` (the UI sets it today).
+        let mut c = config();
+        c.extras.params.insert("artifact".into(), "maven:web/pom.xml".into());
+        assert!(artifact_is_current(root, &base, &c, &[]));
+        std::thread::sleep(std::time::Duration::from_millis(20));
+        fs::write(&source, "<beans><edited/></beans>").unwrap();
+        assert!(!artifact_is_current(root, &base, &c, &[]));
+    }
+
+    #[test]
+    fn up_to_date_check_watches_web_resources_outside_src() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let module = root.join("web");
+        fs::create_dir_all(module.join("src/main/java")).unwrap();
+        fs::create_dir_all(module.join("target")).unwrap();
+        fs::create_dir_all(module.join("WebContent/WEB-INF")).unwrap();
+        fs::write(
+            module.join("pom.xml"),
+            "<project><plugin><artifactId>maven-war-plugin</artifactId><configuration><webResources>\
+             <resource><directory>WebContent</directory></resource></webResources></configuration></plugin></project>",
+        )
+        .unwrap();
+        fs::write(module.join("src/main/java/App.java"), "class App {}").unwrap();
+        let web_xml = module.join("WebContent/WEB-INF/web.xml");
+        fs::write(&web_xml, "<web-app/>").unwrap();
+        let war = module.join("target/app.war");
+        archive(&war, &[("WEB-INF/web.xml", "<web-app/>"), ("index.html", "built")]);
+        let base = root.join("cache");
+        fs::create_dir_all(&base).unwrap();
+        let mut c = config();
+        c.cwd = Some(ide_core::IpcPath(PathBuf::from("web")));
+        c.extras.params.insert("artifact".into(), "maven:web/pom.xml".into());
+        assert!(artifact_is_current(root, &base, &c, &[]));
+        std::thread::sleep(std::time::Duration::from_millis(20));
+        fs::write(&web_xml, "<web-app><edited/></web-app>").unwrap();
+        assert!(!artifact_is_current(root, &base, &c, &[]));
+    }
+
+    #[test]
+    fn up_to_date_check_watches_the_modules_the_war_depends_on() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let web = root.join("web");
+        let dao = root.join("dao");
+        fs::create_dir_all(web.join("src/main/java")).unwrap();
+        fs::create_dir_all(web.join("target")).unwrap();
+        fs::create_dir_all(dao.join("src/main/resources/mapper")).unwrap();
+        fs::write(web.join("pom.xml"), "<project/>").unwrap();
+        fs::write(dao.join("pom.xml"), "<project/>").unwrap();
+        fs::write(web.join("src/main/java/App.java"), "class App {}").unwrap();
+        let mapper = dao.join("src/main/resources/mapper/UserMapper.xml");
+        fs::write(&mapper, "<mapper/>").unwrap();
+        archive(&web.join("target/app.war"), &[("WEB-INF/web.xml", "<web-app/>")]);
+        let base = root.join("cache");
+        fs::create_dir_all(&base).unwrap();
+        let mut c = config();
+        c.cwd = Some(ide_core::IpcPath(PathBuf::from("web")));
+        c.extras.params.insert("artifact".into(), "maven:web/pom.xml".into());
+        let modules = [PathBuf::from(""), PathBuf::from("web"), PathBuf::from("dao")];
+        assert!(artifact_is_current(root, &base, &c, &modules));
+        std::thread::sleep(std::time::Duration::from_millis(20));
+        fs::write(&mapper, "<mapper><select/></mapper>").unwrap();
+        assert!(!artifact_is_current(root, &base, &c, &modules), "a dependency module's XML changed");
+        assert!(artifact_is_current(root, &base, &c, &[]), "without the build's modules only the WAR module counts");
+    }
+
+    #[test]
+    fn artifact_module_prefers_cwd_then_selected_artifact() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let module_of = |cwd: Option<&str>, artifact: Option<&str>| {
+            let mut c = config();
+            c.cwd = cwd.map(|d| ide_core::IpcPath(PathBuf::from(d)));
+            if let Some(id) = artifact {
+                c.extras.params.insert("artifact".into(), id.into());
+            }
+            artifact_module_dir(root, &c)
+        };
+        // The UI keeps `cwd` on the artifact's module; it wins over a stale selection.
+        assert_eq!(module_of(Some("web"), Some("maven:other/pom.xml")), root.join("web"));
+        assert_eq!(module_of(None, Some("maven:web/pom.xml")), root.join("web"));
+        assert_eq!(module_of(None, Some("maven:pom.xml")), root);
+        assert_eq!(module_of(None, Some("gradle::web")), root.join("web"));
+        assert_eq!(module_of(None, Some("gradle::")), root);
+        assert_eq!(module_of(None, Some("gradle:[\"sub\",\":web\"]")), root.join("sub/web"));
+        assert_eq!(module_of(None, Some("other:whatever")), root);
+        assert_eq!(module_of(None, None), root);
+        assert_eq!(module_of(Some("web"), None), root.join("web"));
     }
 
     #[test]

crates/ide-sdk/src/java.rs

@@ -1541,7 +1541,7 @@ pub fn usages_bundle(data_dir: &Path) -> Option<PathBuf> {
     install_bundle(
         data_dir,
         "java-usages",
-        "1.12.0",
+        "1.13.0",
         include_bytes!("../../../java/java-usages/openidea-java-usages.jar"),
     )
 }

crates/ide-sdk/src/libraries.rs

@@ -441,7 +441,7 @@ fn jdk_groups(root: &Path, s: &Settings, cancel: &CancellationToken) -> Vec<Libr
         Some(files) => files,
         None => {
             let java = [".classpath", ".project"].iter().any(|f| root.join(f).is_file())
-                || root.join(".idea").is_dir()
+                || idea_java_project(root)
                 || !s.languages.java.jdk.trim().is_empty()
                 || !s.project_structure.source_roots.is_empty();
             if !java {
@@ -561,6 +561,27 @@ pub(crate) fn classpath_entries(dir: &Path, text: &str) -> Vec<PathBuf> {
 }
 
 /// The JDK home and its sources (`lib/src.zip`, `src.zip` in JDK 8) as library roots.
+/// An IntelliJ project (`.idea`) that is a Java one: a Java SDK or language level in
+/// `misc.xml`, or a Java module file. GoLand, PyCharm and WebStorm write `.idea` too, so the
+/// folder alone doesn't make a project need the JDK.
+fn idea_java_project(root: &Path) -> bool {
+    let idea = root.join(".idea");
+    if !idea.is_dir() {
+        return false;
+    }
+    let misc = std::fs::read_to_string(idea.join("misc.xml")).unwrap_or_default();
+    if misc.contains("JavaSDK") || misc.contains("languageLevel=\"JDK_") {
+        return true;
+    }
+    let java_module = |dir: &Path| {
+        std::fs::read_dir(dir).into_iter().flatten().flatten().any(|e| {
+            e.path().extension().is_some_and(|x| x == "iml")
+                && std::fs::read_to_string(e.path()).is_ok_and(|t| t.contains("JAVA_MODULE"))
+        })
+    };
+    java_module(root) || java_module(&idea)
+}
+
 pub(crate) fn jdk_library(jdk: &crate::java::Jdk) -> Option<LibraryGroup> {
     let name = jdk_name(&jdk.home).unwrap_or_else(|| format!("JDK {}", jdk.major));
     let mut roots = named_roots(vec![(name.clone(), jdk.home.clone())]);
@@ -1263,3 +1284,32 @@ mod go_cache_tests {
         assert_eq!(groups[1].roots.len(), 1);
     }
 }
+
+#[cfg(test)]
+mod idea_project_tests {
+    use super::*;
+
+    #[test]
+    fn an_idea_folder_marks_a_java_project_only_when_it_declares_java() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        assert!(!idea_java_project(root));
+        // GoLand / PyCharm write `.idea` without any Java in it.
+        std::fs::create_dir_all(root.join(".idea")).unwrap();
+        std::fs::write(root.join(".idea/misc.xml"), r#"<project version="4"><component name="GOROOT" /></project>"#)
+            .unwrap();
+        std::fs::write(root.join(".idea/demo.iml"), r#"<module type="WEB_MODULE" version="4" />"#).unwrap();
+        assert!(!idea_java_project(root));
+        // A Java module file, at the root or in `.idea`.
+        std::fs::write(root.join("app.iml"), r#"<module type="JAVA_MODULE" version="4" />"#).unwrap();
+        assert!(idea_java_project(root));
+        std::fs::remove_file(root.join("app.iml")).unwrap();
+        // The project JDK in misc.xml.
+        std::fs::write(
+            root.join(".idea/misc.xml"),
+            r#"<project version="4"><component name="ProjectRootManager" languageLevel="JDK_17" project-jdk-name="17" project-jdk-type="JavaSDK" /></project>"#,
+        )
+        .unwrap();
+        assert!(idea_java_project(root));
+    }
+}

crates/ide-vcs/src/status.rs

@@ -5,6 +5,7 @@ use crate::{ChangeKind, FileStatus, Repo};
 use gix::status::index_worktree::Item as WtItem;
 use gix::status::plumbing::index_as_worktree::{Change as WtChange, EntryStatus};
 use ide_core::IdeResult;
+use ide_core::ignored::IgnoredNames;
 use std::collections::{BTreeMap, HashSet};
 
 #[derive(Default)]
@@ -15,10 +16,43 @@ struct Entry {
 }
 
 pub(crate) fn status(r: &Repo) -> IdeResult<Vec<FileStatus>> {
+    let ignored = r.ignored.read().unwrap_or_else(|p| p.into_inner()).clone();
+    // gitoxide stops at the first IO error (a directory it may not read), where git warns
+    // and lists the rest: git answers then.
+    let (map, conflicts) = gix_status(r, &ignored).or_else(|e| {
+        tracing::debug!("status via gitoxide failed, asking git: {}", e.message);
+        cli_status(r, &ignored)
+    })?;
+    Ok(map
+        .into_iter()
+        .filter(|(_, e)| e.staged.is_some() || e.unstaged.is_some())
+        // Ignored names mean "the IDE treats these as nonexistent": hide their tracked
+        // changes too, not just untracked hits above. Conflicts stay visible so merges
+        // cannot stall on a file the user cannot see.
+        .filter(|(rel, _)| conflicts.contains(rel) || !ignored.is_ignored_path(rel))
+        .map(|(rel, mut e)| {
+            if conflicts.contains(&rel) {
+                e.staged = None;
+                e.renamed_from = None;
+                e.unstaged = Some(ChangeKind::Conflicted);
+            }
+            FileStatus {
+                path: r.abs_path(&rel).into(),
+                rel_path: rel,
+                staged: e.staged,
+                unstaged: e.unstaged,
+                renamed_from: e.renamed_from,
+            }
+        })
+        .collect())
+}
+
+type Entries = (BTreeMap<String, Entry>, HashSet<String>);
+
+fn gix_status(r: &Repo, ignored: &IgnoredNames) -> IdeResult<Entries> {
     let repo = r.gix()?;
     let mut map: BTreeMap<String, Entry> = BTreeMap::new();
     let mut conflicts: HashSet<String> = HashSet::new();
-    let ignored = r.ignored.read().unwrap_or_else(|p| p.into_inner()).clone();
 
     // Stamp before status can read the index: stamping after the load could capture
     // an external `git switch`, `add` or commit's new index and allow the stale
@@ -118,28 +152,60 @@ pub(crate) fn status(r: &Repo) -> IdeResult<Vec<FileStatus>> {
         }
     }
 
-    Ok(map
-        .into_iter()
-        .filter(|(_, e)| e.staged.is_some() || e.unstaged.is_some())
-        // Ignored names mean "the IDE treats these as nonexistent": hide their tracked
-        // changes too, not just untracked hits above. Conflicts stay visible so merges
-        // cannot stall on a file the user cannot see.
-        .filter(|(rel, _)| conflicts.contains(rel) || !ignored.is_ignored_path(rel))
-        .map(|(rel, mut e)| {
-            if conflicts.contains(&rel) {
-                e.staged = None;
-                e.renamed_from = None;
-                e.unstaged = Some(ChangeKind::Conflicted);
+    Ok((map, conflicts))
+}
+
+/// `git status --porcelain=v2`: what git lists, unreadable directories skipped.
+fn cli_status(r: &Repo, ignored: &IgnoredNames) -> IdeResult<Entries> {
+    let out = crate::cli::run(r.root(), &["status", "--porcelain=v2", "-z", "--untracked-files=all"], None)?;
+    Ok(parse_porcelain_v2(&String::from_utf8_lossy(&out.stdout), ignored))
+}
+
+fn parse_porcelain_v2(out: &str, ignored: &IgnoredNames) -> Entries {
+    let kind = |c: u8| match c {
+        b'M' | b'T' => Some(ChangeKind::Modified),
+        b'A' | b'C' => Some(ChangeKind::Added),
+        b'D' => Some(ChangeKind::Deleted),
+        b'R' => Some(ChangeKind::Renamed),
+        _ => None,
+    };
+    let mut map: BTreeMap<String, Entry> = BTreeMap::new();
+    let mut conflicts: HashSet<String> = HashSet::new();
+    let mut records = out.split('\0');
+    while let Some(record) = records.next() {
+        let (tag, rest) = record.split_once(' ').unwrap_or((record, ""));
+        match tag {
+            // `1 XY sub mH mI mW hH hI path`, `2 … Xscore path` + NUL + the original path.
+            "1" | "2" => {
+                let fields = if tag == "1" { 8 } else { 9 };
+                let mut parts = rest.splitn(fields, ' ');
+                let xy = parts.next().unwrap_or("..").as_bytes();
+                let Some(path) = parts.nth(fields - 2) else { continue };
+                let e = map.entry(path.to_owned()).or_default();
+                e.staged = xy.first().copied().and_then(kind);
+                // Intent to add shows as `.A`; worktree renames are off, as with gitoxide.
+                e.unstaged = xy.get(1).copied().and_then(kind).filter(|k| *k != ChangeKind::Renamed);
+                if tag == "2" {
+                    let from = records.next().unwrap_or_default();
+                    if e.staged == Some(ChangeKind::Renamed) {
+                        e.renamed_from = Some(from.to_owned());
+                    }
+                }
             }
-            FileStatus {
-                path: r.abs_path(&rel).into(),
-                rel_path: rel,
-                staged: e.staged,
-                unstaged: e.unstaged,
-                renamed_from: e.renamed_from,
+            // `u XY sub m1 m2 m3 mW h1 h2 h3 path`
+            "u" => {
+                if let Some(path) = rest.splitn(10, ' ').nth(9) {
+                    conflicts.insert(path.to_owned());
+                    map.entry(path.to_owned()).or_default().unstaged = Some(ChangeKind::Conflicted);
+                }
             }
-        })
-        .collect())
+            "?" if !rest.is_empty() && !ignored.is_ignored_path(rest) => {
+                map.entry(rest.to_owned()).or_default().unstaged = Some(ChangeKind::Untracked);
+            }
+            _ => {}
+        }
+    }
+    (map, conflicts)
 }
 
 /// Lets a test land an external index write in the window between the status run
@@ -227,4 +293,59 @@ mod tests {
         let staged = Command::new("git").current_dir(dir).args(["diff", "--cached", "--stat"]).output().unwrap();
         assert!(staged.stdout.is_empty(), "{}", String::from_utf8_lossy(&staged.stdout));
     }
+
+    /// git's porcelain answer (used when gitoxide can't read the tree) matches gitoxide's.
+    #[test]
+    fn git_and_gitoxide_report_the_same_status() {
+        let tmp = tempfile::tempdir().unwrap();
+        let dir = tmp.path();
+        git(dir, &["init", "-q"]);
+        git(dir, &["config", "user.name", "Test User"]);
+        git(dir, &["config", "user.email", "[email protected]"]);
+        git(dir, &["config", "commit.gpgsign", "false"]);
+        for f in ["modified.txt", "staged.txt", "deleted.txt", "staged_del.txt", "both.txt", "conflict.txt"] {
+            std::fs::write(dir.join(f), "a\n").unwrap();
+        }
+        std::fs::write(dir.join("rename_me.txt"), "some longer content\nthat is stable\nfor rename detection\n")
+            .unwrap();
+        commit_all(dir, "base");
+        git(dir, &["checkout", "-q", "-b", "side"]);
+        std::fs::write(dir.join("conflict.txt"), "side\n").unwrap();
+        commit_all(dir, "side");
+        git(dir, &["checkout", "-q", "main"]);
+        std::fs::write(dir.join("conflict.txt"), "main\n").unwrap();
+        commit_all(dir, "main");
+        let merge = Command::new("git").current_dir(dir).args(["merge", "-q", "side"]).output().unwrap();
+        assert!(!merge.status.success());
+
+        std::fs::write(dir.join("modified.txt"), "b\n").unwrap();
+        std::fs::write(dir.join("staged.txt"), "b\n").unwrap();
+        git(dir, &["add", "staged.txt"]);
+        std::fs::remove_file(dir.join("deleted.txt")).unwrap();
+        git(dir, &["rm", "-q", "staged_del.txt"]);
+        std::fs::write(dir.join("both.txt"), "b\n").unwrap();
+        git(dir, &["add", "both.txt"]);
+        std::fs::write(dir.join("both.txt"), "c\n").unwrap();
+        git(dir, &["mv", "rename_me.txt", "renamed with space.txt"]);
+        std::fs::create_dir_all(dir.join("new dir")).unwrap();
+        std::fs::write(dir.join("new dir/untracked.txt"), "u\n").unwrap();
+        std::fs::write(dir.join("intent.txt"), "i\n").unwrap();
+        git(dir, &["add", "-N", "intent.txt"]);
+
+        let repo = Repo::discover(dir).unwrap().expect("repository found");
+        let ignored = IgnoredNames::default();
+        let show = |(map, conflicts): Entries| {
+            let mut c: Vec<_> = conflicts.into_iter().collect();
+            c.sort();
+            let m: Vec<_> = map
+                .into_iter()
+                .map(|(k, e)| format!("{k}: {:?} {:?} {:?}", e.staged, e.unstaged, e.renamed_from))
+                .collect();
+            (m, c)
+        };
+        let from_git = show(cli_status(&repo, &ignored).unwrap());
+        assert_eq!(from_git, show(gix_status(&repo, &ignored).unwrap()));
+        assert!(from_git.0.iter().any(|l| l.starts_with("renamed with space.txt: Some(Renamed)")), "{from_git:?}");
+        assert_eq!(from_git.1, ["conflict.txt"]);
+    }
 }

crates/ide-vcs/tests/repo.rs

@@ -2015,3 +2015,24 @@ fn reword_refuses_commits_outside_the_current_branch() {
     fx.git(&["checkout", "-q", "main"]);
     assert!(fx.repo().reword(&side, "other").is_err());
 }
+
+#[cfg(unix)]
+#[test]
+fn status_skips_a_directory_it_cannot_read() {
+    // `git status` warns "could not open directory: Permission denied" and lists the rest.
+    use std::os::unix::fs::PermissionsExt;
+    let fx = Fixture::new();
+    fx.write("a.txt", "a\n");
+    fx.commit_all("init");
+    fx.write("a.txt", "b\n");
+    fx.write("new.txt", "n\n");
+    let locked = fx.path("locked");
+    std::fs::create_dir(&locked).unwrap();
+    std::fs::write(locked.join("inside.txt"), "x").unwrap();
+    std::fs::set_permissions(&locked, std::fs::Permissions::from_mode(0o000)).unwrap();
+    let st = fx.repo().status();
+    std::fs::set_permissions(&locked, std::fs::Permissions::from_mode(0o755)).unwrap();
+    let st = st.unwrap();
+    assert_eq!(status_of(&st, "a.txt").unstaged, Some(ChangeKind::Modified));
+    assert_eq!(status_of(&st, "new.txt").unstaged, Some(ChangeKind::Untracked));
+}

crates/ide-vfs/src/encoding.rs

@@ -359,6 +359,32 @@ fn sync_error_is_tolerable(e: &std::io::Error) -> bool {
     false
 }
 
+/// On Windows a file can't be replaced while another process has it open without
+/// delete sharing: an antivirus or indexer scan, a sync client, a program reading
+/// its config. Those let go within moments, so the replacing rename is retried briefly.
+const RENAME_ATTEMPTS: u32 = 10;
+const RENAME_PAUSE: std::time::Duration = std::time::Duration::from_millis(100);
+
+/// Access denied (os error 5), sharing and lock violations (32, 33) on Windows.
+fn held_by_another_process(e: &std::io::Error) -> bool {
+    cfg!(windows) && matches!(e.raw_os_error(), Some(5 | 32 | 33))
+}
+
+fn retrying(
+    attempts: u32,
+    pause: std::time::Duration,
+    transient: impl Fn(&std::io::Error) -> bool,
+    mut op: impl FnMut() -> std::io::Result<()>,
+) -> std::io::Result<()> {
+    for _ in 1..attempts {
+        match op() {
+            Err(e) if transient(&e) => std::thread::sleep(pause),
+            r => return r,
+        }
+    }
+    op()
+}
+
 /// Writes `bytes` to `path` atomically: temp file in the same directory, fsync,
 /// rename over the target. Preserves the permissions of an existing file and
 /// writes through symlinks. Falls back to an in-place write when the directory
@@ -441,7 +467,7 @@ fn write_atomic_impl(path: &Path, bytes: &[u8], allow_in_place: bool, private: b
             fs::set_permissions(&tmp, permissions)?;
         }
         drop(file);
-        fs::rename(&tmp, &target)
+        retrying(RENAME_ATTEMPTS, RENAME_PAUSE, held_by_another_process, || fs::rename(&tmp, &target))
     })();
     if let Err(e) = result {
         let _ = fs::remove_file(&tmp);
@@ -539,6 +565,58 @@ mod tests {
         assert_eq!(fs::metadata(&target).unwrap().permissions().mode() & 0o777, 0o640);
     }
 
+    #[test]
+    fn replacing_is_retried_only_while_a_file_is_held() {
+        use std::io::{Error, ErrorKind};
+        let in_use = || Error::from_raw_os_error(32);
+        let transient = |e: &Error| e.raw_os_error() == Some(32);
+        let zero = std::time::Duration::ZERO;
+        for (fails, outcome) in [(0, true), (3, true), (RENAME_ATTEMPTS - 1, true), (RENAME_ATTEMPTS, false)] {
+            let mut calls = 0;
+            let r = retrying(RENAME_ATTEMPTS, zero, transient, || {
+                calls += 1;
+                if calls <= fails { Err(in_use()) } else { Ok(()) }
+            });
+            assert_eq!(r.is_ok(), outcome, "{fails} failures");
+            assert_eq!(calls, (fails + 1).min(RENAME_ATTEMPTS));
+        }
+        let mut calls = 0;
+        let r = retrying(RENAME_ATTEMPTS, zero, transient, || {
+            calls += 1;
+            Err(Error::from(ErrorKind::NotFound))
+        });
+        assert_eq!(r.unwrap_err().kind(), ErrorKind::NotFound);
+        assert_eq!(calls, 1, "other errors fail at once");
+
+        for code in [5, 32, 33] {
+            assert_eq!(held_by_another_process(&Error::from_raw_os_error(code)), cfg!(windows), "os error {code}");
+        }
+        assert!(!held_by_another_process(&Error::from(ErrorKind::NotFound)));
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn saving_waits_for_a_windows_file_lock_to_be_released() {
+        use std::os::windows::fs::OpenOptionsExt;
+        use windows_sys::Win32::Storage::FileSystem::{FILE_SHARE_READ, FILE_SHARE_WRITE};
+        // No sharing at all (os error 32), and readers that don't allow deletion (os error 5).
+        for share in [0, FILE_SHARE_READ | FILE_SHARE_WRITE] {
+            let dir = tempfile::tempdir().unwrap();
+            let path = dir.path().join("config.json");
+            fs::write(&path, b"old").unwrap();
+            let held = fs::OpenOptions::new().read(true).share_mode(share).open(&path).unwrap();
+            let release = std::thread::spawn(move || {
+                std::thread::sleep(std::time::Duration::from_millis(300));
+                drop(held);
+            });
+            let result = write_atomic(&path, b"new");
+            release.join().unwrap();
+            result.unwrap();
+            assert_eq!(fs::read(&path).unwrap(), b"new", "share mode {share}");
+            assert_eq!(fs::read_dir(dir.path()).unwrap().count(), 1, "no temp file left behind");
+        }
+    }
+
     #[cfg(unix)]
     #[test]
     fn strict_write_does_not_truncate_when_sibling_creation_is_denied() {

crates/ide-workspace/src/documents.rs

@@ -25,6 +25,11 @@ pub struct DocumentInfo {
     pub line_ending: LineEnding,
     pub read_only: bool,
     pub dirty: bool,
+    /// Whether "Reload with Encoding" can re-decode this document's source
+    /// bytes: true for files and virtual documents the backend can re-read
+    /// (archive entries, JDT sources with an editable attachment encoding,
+    /// Git revisions); false for server-generated content (decompiled code).
+    pub can_reload_encoding: bool,
     /// Larger than `ide_vfs::LARGE_FILE_THRESHOLD`: language servers, syntax
     /// structure and folding are disabled; the editor should drop heavy features.
     #[specta(optional)]
@@ -143,6 +148,9 @@ struct DocState {
     observed: bool,
     binary: bool,
     dirty: bool,
+    can_reload_encoding: bool,
+    /// The user picked `encoding`; reloads keep it instead of detecting again.
+    encoding_chosen: bool,
     /// Disk state we last loaded or wrote; changes matching it are our own.
     disk_mtime: f64,
     disk_len: u64,
@@ -339,6 +347,7 @@ impl Documents {
             line_ending: st.doc.line_ending(),
             read_only: st.read_only,
             dirty: st.dirty,
+            can_reload_encoding: st.can_reload_encoding,
             large: st.large,
             editorconfig: st.editorconfig.clone(),
             uri: st.uri.clone(),
@@ -412,6 +421,8 @@ impl Documents {
             observed,
             binary: loaded.binary,
             dirty: false,
+            can_reload_encoding: true,
+            encoding_chosen: false,
             disk_mtime: loaded.mtime_ms,
             disk_len: disk_len(path),
             closed: false,
@@ -449,8 +460,19 @@ impl Documents {
 
     /// Opens (or re-references) a read-only virtual document: contents a
     /// language server provides for a non-`file:` URI. It is keyed by the URI,
-    /// never touches the disk and cannot be edited or saved.
-    pub fn open_virtual(&self, uri: &str, language: LanguageId, text: &str) -> IdeResult<DocumentInfo> {
+    /// never touches the disk and cannot be edited or saved. `encoding` /
+    /// `has_bom` describe how the content was decoded (not a guess);
+    /// `can_reload_encoding` tells whether [`Documents::replace_virtual`] can
+    /// re-decode it ("Reload with Encoding").
+    pub fn open_virtual(
+        &self,
+        uri: &str,
+        language: LanguageId,
+        text: &str,
+        encoding: &str,
+        has_bom: bool,
+        can_reload_encoding: bool,
+    ) -> IdeResult<DocumentInfo> {
         let _operation = self.operations.lock();
         let key = PathBuf::from(uri);
         if let Some(info) = self.reopen(&key) {
@@ -462,8 +484,8 @@ impl Documents {
             doc: Document::new(text),
             language,
             ui_mode: None,
-            encoding: "utf-8".into(),
-            has_bom: false,
+            encoding: encoding.into(),
+            has_bom,
             native_to_ascii: false,
             read_only: true,
             large,
@@ -471,6 +493,8 @@ impl Documents {
             observed: true,
             binary: false,
             dirty: false,
+            can_reload_encoding,
+            encoding_chosen: false,
             disk_mtime: 0.0,
             disk_len: 0,
             closed: false,
@@ -846,6 +870,7 @@ impl Documents {
                 let loaded = Self::load_as(&st.path, encoding, enabled)?;
                 st.native_to_ascii = enabled;
                 st.encoding = loaded.encoding.clone();
+                st.encoding_chosen = true;
                 st.has_bom = loaded.has_bom;
                 st.disk_mtime = loaded.mtime_ms;
                 st.disk_len = disk_len(&st.path);
@@ -864,12 +889,45 @@ impl Documents {
                 ide_vfs::encode(&st.doc.text_for_save(), encoding, has_bom)?;
             }
             st.encoding = encoding.to_owned();
+            st.encoding_chosen = true;
             st.has_bom = has_bom;
             self.set_dirty(doc, st, true);
             Ok(DocumentEncoding { encoding: st.encoding.clone(), has_bom: st.has_bom })
         })
     }
 
+    /// The URI of a virtual document, or `None` for a file-backed one.
+    pub fn virtual_uri(&self, doc: DocId) -> IdeResult<Option<String>> {
+        self.with_doc(doc, |st| Ok(st.uri.clone()))
+    }
+
+    /// Re-decoded content of a virtual document ("Reload with Encoding"):
+    /// replaces the text and the encoding label, keeping the document
+    /// read-only and clean. The caller re-reads the origin (archive entry,
+    /// language server, Git blob) with the chosen encoding first.
+    pub fn replace_virtual(
+        &self,
+        doc: DocId,
+        text: &str,
+        encoding: &str,
+        has_bom: bool,
+    ) -> IdeResult<DocumentEncoding> {
+        self.with_doc(doc, |st| {
+            if st.uri.is_none() {
+                return Err(IdeError::invalid("not a virtual document"));
+            }
+            ide_vfs::encode("", encoding, false)?;
+            st.doc.set_line_ending(LineEnding::detect(text));
+            self.replace_locked(doc, st, text)?;
+            st.encoding = encoding.to_owned();
+            st.has_bom = has_bom;
+            st.large = text.len() as u64 > ide_vfs::LARGE_FILE_THRESHOLD;
+            // Reloading is not an edit: the buffer matches its source again.
+            self.set_dirty(doc, st, false);
+            Ok(DocumentEncoding { encoding: st.encoding.clone(), has_bom: st.has_bom })
+        })
+    }
+
     /// Adds or removes the BOM on a UTF-8 document; the change is written on save.
     pub fn set_bom(&self, doc: DocId, has_bom: bool) -> IdeResult<DocumentEncoding> {
         self.with_doc(doc, |st| {
@@ -968,8 +1026,13 @@ impl Documents {
                     Self::load_as(&st.path, &st.encoding, st.native_to_ascii)?
                 } else {
                     let defaults = self.file_defaults();
-                    let loaded = Self::load_with_defaults(&st.path, &defaults)?;
-                    st.native_to_ascii = defaults.native_to_ascii_for(&st.path);
+                    let native_to_ascii = defaults.native_to_ascii_for(&st.path);
+                    let loaded = if st.encoding_chosen {
+                        Self::load_as(&st.path, &st.encoding, native_to_ascii)?
+                    } else {
+                        Self::load_with_defaults(&st.path, &defaults)?
+                    };
+                    st.native_to_ascii = native_to_ascii;
                     loaded
                 };
                 st.disk_mtime = loaded.mtime_ms;

crates/ide-workspace/src/documents/workspace_edit.rs

@@ -748,6 +748,7 @@ impl Documents {
             let result = self.with_doc(*id, |state| {
                 self.replace_locked(*id, state, &before.doc.text())?;
                 state.encoding = before.encoding.clone();
+                state.encoding_chosen = before.encoding_chosen;
                 state.has_bom = before.has_bom;
                 state.doc.set_line_ending(before.doc.line_ending());
                 state.disk_mtime = fs::metadata(&state.path).map(|m| ide_vfs::mtime_ms(&m)).unwrap_or(0.0);
@@ -789,7 +790,11 @@ impl Documents {
                     return Err(stale(path));
                 }
                 let defaults = self.file_defaults();
-                let loaded = ide_vfs::load_text_with_fallback(path, defaults.fallback_for(path))?;
+                let loaded = if state.encoding_chosen {
+                    Self::load_as(path, &state.encoding, state.native_to_ascii)?
+                } else {
+                    ide_vfs::load_text_with_fallback(path, defaults.fallback_for(path))?
+                };
                 self.replace_locked(id, state, &loaded.text)?;
                 state.encoding = loaded.encoding;
                 state.has_bom = loaded.has_bom;

crates/ide-workspace/tests/documents.rs

@@ -505,6 +505,48 @@ fn reload_and_convert_encoding() {
     assert!(f.docs.set_encoding(info.id, "gbk", true).is_err());
 }
 
+#[test]
+fn external_changes_keep_a_chosen_encoding() {
+    // Valid UTF-8 bytes, so detection alone would read them as UTF-8.
+    let (first, changed) = (b"caf\xC3\xA9".as_slice(), b"caf\xC3\xA9 \xC3\xA8".as_slice());
+    for (encoding, reload) in [("windows-1252", true), ("gbk", true), ("windows-1252", false)] {
+        let f = fixture();
+        let path = f.root.join("legacy.txt");
+        fs::write(&path, first).unwrap();
+        let info = f.docs.open(&path).unwrap();
+        assert_eq!(info.encoding, "utf-8");
+        if reload {
+            f.docs.set_encoding(info.id, encoding, true).unwrap();
+        } else {
+            // Convert, then save: the file is now in the chosen encoding.
+            f.docs.replace_all(info.id, "café").unwrap();
+            f.docs.set_encoding(info.id, encoding, false).unwrap();
+            f.docs.save(info.id).unwrap();
+        }
+        let expected =
+            |bytes: &[u8]| encoding_rs::Encoding::for_label(encoding.as_bytes()).unwrap().decode(bytes).0.into_owned();
+        let changed = if reload { changed.to_vec() } else { ide_vfs::encode("café è", encoding, false).unwrap() };
+        fs::write(&path, &changed).unwrap();
+        f.docs.on_disk_changed(std::slice::from_ref(&path));
+        let snapshot = f.docs.snapshot(info.id).unwrap();
+        assert_eq!(snapshot.text, expected(&changed), "{encoding} reload={reload}");
+        assert_eq!(snapshot.encoding, encoding, "{encoding} reload={reload}");
+        assert!(!snapshot.dirty);
+    }
+}
+
+#[test]
+fn external_changes_redetect_an_encoding_the_user_never_chose() {
+    let f = fixture();
+    let path = f.root.join("plain.txt");
+    fs::write(&path, "plain").unwrap();
+    let info = f.docs.open(&path).unwrap();
+    fs::write(&path, ide_vfs::encode("wide", "utf-16le", true).unwrap()).unwrap();
+    f.docs.on_disk_changed(std::slice::from_ref(&path));
+    let snapshot = f.docs.snapshot(info.id).unwrap();
+    assert_eq!((snapshot.text.as_str(), snapshot.encoding.as_str()), ("wide", "utf-16le"));
+}
+
 #[test]
 fn utf8_bom_is_added_and_removed_on_save() {
     let f = fixture();
@@ -656,14 +698,14 @@ fn editorconfig_applies_on_open_and_save() {
 fn virtual_documents_are_read_only_and_keyed_by_uri() {
     let f = fixture();
     let uri = "jdt://contents/a.jar/p/C.class?=x";
-    let info = f.docs.open_virtual(uri, LanguageId::new("java"), "class C {}\n").unwrap();
+    let info = f.docs.open_virtual(uri, LanguageId::new("java"), "class C {}\n", "utf-8", false, true).unwrap();
     assert_eq!(info.uri.as_deref(), Some(uri));
     assert_eq!(info.path, PathBuf::from(uri));
     assert!(info.read_only && !info.dirty);
     assert_eq!(info.language.as_str(), "java");
 
     // Re-opening shares the document; edits and saves never reach a file.
-    let again = f.docs.open_virtual(uri, LanguageId::new("java"), "ignored").unwrap();
+    let again = f.docs.open_virtual(uri, LanguageId::new("java"), "ignored", "utf-8", false, true).unwrap();
     assert_eq!(again.id, info.id);
     assert_eq!(again.text, "class C {}\n");
     let err = f.docs.edit(info.id, info.version, change(0, 0, "x")).unwrap_err();
@@ -677,6 +719,68 @@ fn virtual_documents_are_read_only_and_keyed_by_uri() {
     assert_eq!(*f.rec.log.lock(), vec!["open v0 java".to_owned(), "close".to_owned()]);
 }
 
+#[test]
+fn virtual_documents_carry_their_encoding_and_reload_capability() {
+    let f = fixture();
+    // Archive sources decoded by the backend report the charset actually used.
+    let uri = "jar:///m2/lib-1.0-sources.jar!/p/C.java";
+    let info = f.docs.open_virtual(uri, LanguageId::new("java"), "中文", "gbk", false, true).unwrap();
+    assert_eq!((info.encoding.as_str(), info.has_bom, info.can_reload_encoding), ("gbk", false, true));
+    let bom =
+        f.docs.open_virtual("jar:///m2/b.jar!/p/B.java", LanguageId::new("java"), "x", "utf-8", true, true).unwrap();
+    assert!(bom.has_bom);
+    // Server-generated content (decompiled) cannot be re-decoded.
+    let decompiled = f
+        .docs
+        .open_virtual(
+            "csharp:/p/App.csproj/decompiled/Lib.cs",
+            LanguageId::new("csharp"),
+            "class Lib {}",
+            "utf-8",
+            false,
+            false,
+        )
+        .unwrap();
+    assert!(!decompiled.can_reload_encoding);
+    // File-backed documents can always be re-read from disk.
+    let path = f.root.join("f.txt");
+    fs::write(&path, "x").unwrap();
+    assert!(f.docs.open(&path).unwrap().can_reload_encoding);
+}
+
+#[test]
+fn virtual_documents_reload_with_another_encoding_without_becoming_editable() {
+    let f = fixture();
+    let uri = "jdt://contents/a.jar/p/C.class?=x";
+    let info = f.docs.open_virtual(uri, LanguageId::new("java"), "涓枃", "utf-8", false, true).unwrap();
+    let encoding = f.docs.replace_virtual(info.id, "中文", "gbk", false).unwrap();
+    assert_eq!((encoding.encoding.as_str(), encoding.has_bom), ("gbk", false));
+    let snap = f.docs.snapshot(info.id).unwrap();
+    assert_eq!(snap.text, "中文");
+    assert_eq!(snap.encoding, "gbk");
+    assert!(snap.read_only && !snap.dirty, "reloading is not an edit");
+    assert!(snap.version > info.version);
+    assert_eq!(f.docs.virtual_uri(info.id).unwrap().as_deref(), Some(uri));
+    // The replacement reached observers and the event stream (editors resync).
+    assert!(f.rec.log.lock().iter().any(|l| l.starts_with("change v") && l.contains("中文")));
+    assert!(f.events.lock().iter().any(|e| matches!(e, IdeEvent::DocPatched { doc, .. } if *doc == info.id)));
+
+    // Read-only protection is unchanged.
+    assert_eq!(f.docs.edit(info.id, snap.version, change(0, 0, "x")).unwrap_err().kind, ErrorKind::PermissionDenied);
+    assert!(f.docs.set_encoding(info.id, "utf-8", false).is_err());
+    assert!(f.docs.set_encoding(info.id, "gbk", true).is_err(), "the op layer routes virtual reloads");
+    assert!(f.docs.set_bom(info.id, true).is_err());
+    f.docs.save(info.id).unwrap();
+
+    // Unknown encodings are refused; file-backed documents are not virtual.
+    assert!(f.docs.replace_virtual(info.id, "x", "not-an-encoding", false).is_err());
+    let path = f.root.join("f.txt");
+    fs::write(&path, "x").unwrap();
+    let file = f.docs.open(&path).unwrap();
+    assert!(f.docs.replace_virtual(file.id, "y", "utf-8", false).is_err());
+    assert_eq!(f.docs.virtual_uri(file.id).unwrap(), None);
+}
+
 #[test]
 fn toggling_the_writable_bit_updates_the_open_document() {
     let f = fixture();

crates/ide-workspace/tests/workspace_edits.rs

@@ -162,6 +162,21 @@ fn undo_id(events: &Mutex<Vec<IdeEvent>>) -> u32 {
         .expect("successful transaction has one undo record")
 }
 
+#[test]
+fn undo_keeps_the_encoding_chosen_for_a_file_opened_after_the_edit() {
+    let tmp = tempfile::tempdir().unwrap();
+    let path = tmp.path().join("legacy.txt");
+    std::fs::write(&path, b"abc\xC3\xA9").unwrap();
+    let (docs, events) = recorded_documents();
+    docs.apply_workspace_edit(&WorkspaceEdit { files: vec![edit(&path, "new")], ..Default::default() }).unwrap();
+    let info = docs.open(&path).unwrap();
+    docs.set_encoding(info.id, "windows-1252", true).unwrap();
+    assert_eq!(docs.snapshot(info.id).unwrap().text, "newé");
+    docs.undo_workspace_edit(undo_id(&events)).unwrap();
+    let snapshot = docs.snapshot(info.id).unwrap();
+    assert_eq!((snapshot.text.as_str(), snapshot.encoding.as_str()), ("abcé", "windows-1252"));
+}
+
 #[test]
 fn stale_document_version_rejects_the_whole_edit() {
     let tmp = tempfile::tempdir().unwrap();
@@ -515,6 +530,18 @@ fn duplicate_edits_keep_versions_and_apply_one_replacement() {
     assert_eq!(std::fs::read_to_string(path).unwrap(), "new_long");
 }
 
+#[test]
+fn repeated_inserts_at_one_position_all_apply_once_per_entry() {
+    let tmp = tempfile::tempdir().unwrap();
+    let path = tmp.path().join("main.ts");
+    std::fs::write(&path, "f(").unwrap();
+    let docs = documents();
+    let close = TextEdit { range: Range::new(Pos::new(0, 2), Pos::new(0, 2)), new_text: ")".into() };
+    let entry = FileEdit::Edit { path: path.clone().into(), version: None, edits: vec![close.clone(), close] };
+    docs.apply_workspace_edit(&WorkspaceEdit { files: vec![entry.clone(), entry], ..Default::default() }).unwrap();
+    assert_eq!(std::fs::read_to_string(&path).unwrap(), "f())");
+}
+
 #[test]
 fn undo_accepts_typing_that_was_reverted_to_the_saved_refactoring() {
     let tmp = tempfile::tempdir().unwrap();

docs/en/languages/index.mdx

@@ -11,9 +11,10 @@ Each open file gets its language from the definitions, checked in this order:
 
 1. A per-file **Override File Type** (in the context menu of a file in the project tree or of an editor tab).
 2. An exact file name (`Dockerfile`, `go.mod`) or a file name pattern.
-3. The extension, longest match first (`.html.erb` before `.erb`).
-4. The first line: a shebang such as `#!/usr/bin/env python3`, or a pattern such as `<?php`.
-5. Otherwise the file is plain text.
+3. A framework's folder: an `.html` or `.txt` file in a `templates` folder with a `manage.py` above it is a Django template.
+4. The extension, longest match first (`.html.erb` before `.erb`).
+5. The first line: a shebang such as `#!/usr/bin/env python3`, or a pattern such as `<?php`.
+6. Otherwise the file is plain text.
 
 You can add or remove file name patterns per language in **Settings › Editor › File Types** (**Recognized File Types**).
 
@@ -106,6 +107,7 @@ The table lists every built-in language definition. Server and debugger names in
 | D                   | `d`                | `.d`, `.di`                                                 | Yes          | —           | serve-d                                                                               | —                        |
 | Dart                | `dart`             | `.dart`                                                     | Yes          | Yes         | dart                                                                                  | dart                     |
 | Diff                | `diff`             | `.diff`, `.patch`, `.rej`                                   | Yes          | —           | —                                                                                     | —                        |
+| Django Template     | `django-html`      | `.djhtml`, `templates/*.html`, `*.txt`                      | Yes          | Yes         | **vscode-html-language-server**                                                       | —                        |
 | Dockerfile          | `dockerfile`       | `.dockerfile`, `.containerfile`                             | Yes          | —           | **dockerfile-language-server**                                                        | —                        |
 | Elixir              | `elixir`           | `.ex`, `.exs`                                               | Yes          | Yes         | **elixir-ls**                                                                         | **elixir-ls-debugger**   |
 | ERB                 | `erb`              | `.erb`, `.html.erb`, `.rhtml`, `.js.erb`, `.text.erb`, …    | Yes          | —           | —                                                                                     | —                        |

docs/en/languages/python.mdx

@@ -125,6 +125,12 @@ See [Debugging](/en/guide/debugging) for breakpoints, stepping and the debugger
 
 Django is the only framework with dedicated support: the `manage.py runserver` and `manage.py test` configurations, the **Django tests** configuration type (target, settings module, options), running single `TestCase` tests from the gutter, and Django mode in the debugger. Other frameworks (Flask, FastAPI and so on) run as ordinary scripts or console scripts.
 
+### Django templates
+
+The HTML and text files in a `templates` folder of a Django project (one with a `manage.py` above it) open as **Django Template** files: the template tags, variables, filters and comments are highlighted on top of the HTML, and block tags (`{% block %}`, `{% if %}`, `{% for %}`, `{% with %}` and the others of Django and its contrib libraries) fold, indent their content and highlight their end tag. Typing `{%`, `{{` or `{#` closes the pair, finishing a block tag adds its end tag, and `{% end` completes the end tags of the open blocks. **Comment with Line Comment** puts each line in its own `{# … #}`, and **Comment with Block Comment** over several lines uses `{% comment %}`. The HTML language server and Emmet work in the markup between the tags.
+
+An HTML file elsewhere with Django tags shows a banner that switches it to Django Template or keeps it as HTML; either choice is the file's **Override File Type**.
+
 ## Limitations
 
 - Only one type checker runs at a time. Ruff runs only in projects with a Ruff configuration.

docs/en/reference/settings.mdx

@@ -52,7 +52,6 @@ exclude = ["**/.git", "**/node_modules", "**/target", "**/dist"]
 | Editor                       | General (Auto Import, Appearance, Breadcrumbs, Code Completion, Code Folding, Editor Tabs, Gutter Icons, Inline Completion, Postfix Completion, Rich-Text Copy, Smart Keys, Sticky Lines); Code Editing; Font; Color Scheme; Code Style; Inspections; Natural Languages (Spelling); File and Code Templates; File Encodings; Live Templates; File Types; Inlay Hints; TODO; Vim |
 | Plugins                      | Plugins                                                                                                                                                                                                                                                                                                                                                                         |
 | Version Control              | Commit; Confirmation; Directory Mappings; Issue Navigation; Log; Shelf; Git; GitHub                                                                                                                                                                                                                                                                                             |
-| Project Structure            | Project Structure                                                                                                                                                                                                                                                                                                                                                               |
 | Build, Execution, Deployment | CMake; Gradle; Maven; Console; Debugger (Data Views, Stepping); Python Debugger; Run/Debug; Run Targets; Deployment (Options)                                                                                                                                                                                                                                                   |
 | Languages & Frameworks       | Language Servers; Go (Build Tags, Go Modules); Java; Markdown; Node.js; PHP; Python Interpreter; Prettier; oxfmt; Ruff; Ruby; Rust; TypeScript                                                                                                                                                                                                                                  |
 | Tools                        | Agents (Chat); Terminal; Actions on Save; External Tools; SSH Configurations; MCP Server                                                                                                                                                                                                                                                                                        |

docs/zh/languages/index.mdx

@@ -11,9 +11,10 @@ OpenIDEA 用一个小的定义文件 `languages/<id>.toml` 描述每种语言：
 
 1. 单个文件的 **覆盖文件类型**（在项目树中文件的右键菜单或编辑器标签页的右键菜单里）。
 2. 精确文件名（`Dockerfile`、`go.mod`）或文件名模式。
-3. 扩展名，优先匹配最长的（`.html.erb` 先于 `.erb`）。
-4. 文件第一行：例如 `#!/usr/bin/env python3` 这样的 shebang，或 `<?php` 这类模式。
-5. 都不匹配时按纯文本处理。
+3. 框架目录：上层目录有 `manage.py` 的 `templates` 目录中的 `.html` 或 `.txt` 文件是 Django 模板。
+4. 扩展名，优先匹配最长的（`.html.erb` 先于 `.erb`）。
+5. 文件第一行：例如 `#!/usr/bin/env python3` 这样的 shebang，或 `<?php` 这类模式。
+6. 都不匹配时按纯文本处理。
 
 在 **设置 › 编辑器 › 文件类型**（**已识别的文件类型**）中可以为某种语言添加或移除文件名模式。
 
@@ -101,6 +102,7 @@ IDE 安装工具从不需要 `sudo`。工具装在本地数据目录下 IDE 自
 | D                   | `d`                | `.d`, `.di`                                                 | 是   | —           | serve-d                                                                               | —                        |
 | Dart                | `dart`             | `.dart`                                                     | 是   | 是          | dart                                                                                  | dart                     |
 | Diff                | `diff`             | `.diff`, `.patch`, `.rej`                                   | 是   | —           | —                                                                                     | —                        |
+| Django Template     | `django-html`      | `.djhtml`, `templates/*.html`, `*.txt`                      | 是   | 是          | **vscode-html-language-server**                                                       | —                        |
 | Dockerfile          | `dockerfile`       | `.dockerfile`, `.containerfile`                             | 是   | —           | **dockerfile-language-server**                                                        | —                        |
 | Elixir              | `elixir`           | `.ex`, `.exs`                                               | 是   | 是          | **elixir-ls**                                                                         | **elixir-ls-debugger**   |
 | ERB                 | `erb`              | `.erb`, `.html.erb`, `.rhtml`, `.js.erb`, `.text.erb`, …    | 是   | —           | —                                                                                     | —                        |

docs/zh/languages/python.mdx

@@ -125,6 +125,12 @@ Python 调试使用 debugpy。开始调试时如果缺少 debugpy，OpenIDEA 会
 
 目前只有 Django 有专门支持：`manage.py runserver` 和 `manage.py test` 运行配置、**Django 测试** 配置类型（目标、settings 模块、选项）、在左侧栏运行单个 `TestCase` 测试，以及调试器的 Django 模式。Flask、FastAPI 等其他框架按普通脚本或命令行入口运行。
 
+### Django 模板
+
+Django 项目（上层目录有 `manage.py`）中 `templates` 目录里的 HTML 和文本文件以 **Django Template** 打开：模板标签、变量、过滤器和注释在 HTML 之上高亮，块标签（`{% block %}`、`{% if %}`、`{% for %}`、`{% with %}` 以及 Django 和其 contrib 库的其他块标签）可以折叠、缩进内容并高亮对应的结束标签。输入 `{%`、`{{` 或 `{#` 会自动补全成对符号，写完块标签会自动添加结束标签，输入 `{% end` 会补全当前打开块的结束标签。**使用行注释** 会把每一行放进各自的 `{# … #}`，多行的 **使用块注释** 则用 `{% comment %}`。HTML 语言服务器和 Emmet 在标签之间的标记中照常工作。
+
+其他位置含有 Django 标签的 HTML 文件会显示一个横幅，可以切换为 Django Template 或保留为 HTML；两种选择都会成为该文件的 **覆盖文件类型**。
+
 ## 限制
 
 - 同一时间只运行一个类型检查器。Ruff 只在有 Ruff 配置的项目中运行。

docs/zh/reference/settings.mdx

@@ -52,7 +52,6 @@ exclude = ["**/.git", "**/node_modules", "**/target", "**/dist"]
 | 编辑器           | 常规（自动导入、外观、痕迹导航、代码补全、代码折叠、编辑器标签页、装订区域图标、内联补全、后缀补全、富文本复制、智能键、粘滞行）；代码编辑；字体；配色方案；代码样式；检查；自然语言（拼写）；文件和代码模板；文件编码；实时模板；文件类型；嵌入提示；TODO；Vim |
 | 插件             | 插件                                                                                                                                                                                                                                                            |
 | 版本控制         | 提交；确认；目录映射；问题导航；日志；搁置；Git；GitHub                                                                                                                                                                                                         |
-| 项目结构         | 项目结构                                                                                                                                                                                                                                                        |
 | 构建、执行、部署 | CMake；Gradle；Maven；控制台；调试器（数据视图、单步执行）；Python 调试器；运行/调试；运行目标；部署（选项）                                                                                                                                                    |
 | 语言和框架       | 语言服务器；Go（构建标签、Go 模块）；Java；Markdown；Node.js；PHP；Python 解释器；Prettier；oxfmt；Ruff；Ruby；Rust；TypeScript                                                                                                                                 |
 | 工具             | 智能体（聊天）；终端；保存时操作；外部工具；SSH 配置；MCP 服务器                                                                                                                                                                                                |

e2e/settingsPaneLayout.spec.ts

@@ -85,16 +85,13 @@ for (const id of ["editor.fileTemplates", "editor.liveTemplates"]) {
 }
 
 test("Project Structure keeps every details pane usable in a compact window", async ({ workbench: page }) => {
-  await page.keyboard.press("Meta+,");
-  await expect(page.getByRole("dialog", { name: "Settings", exact: true })).toBeVisible();
-  await page.evaluate(async () => {
-    const path = "/src/features/settings/model/staging.ts";
-    (await import(/* @vite-ignore */ path)).selectPage("projectStructure");
-  });
+  await page.keyboard.press("Meta+;");
+  const dialog = page.getByRole("dialog", { name: "Project Structure", exact: true });
+  await expect(dialog).toBeVisible();
   await page.setViewportSize({ width: 520, height: 760 });
   for (const section of ["Modules", "Libraries", "Facets", "Artifacts", "SDKs"]) {
-    await page.getByRole("tab", { name: section, exact: true }).click();
-    const details = page.locator("[class*='splitLayout'] > [class*='detailPane']");
+    await dialog.getByRole("button", { name: section, exact: true }).click();
+    const details = dialog.locator("[class*='splitLayout'] > [class*='detailPane']");
     await expect(details).toBeAttached();
     expect((await details.boundingBox())!.width).toBeGreaterThan(200);
   }

e2e/terminal-ui.spec.ts

@@ -93,6 +93,36 @@ test("terminal highlights visible occurrences of selected text in a single overl
     activeSession()!.term.clearSelection();
   });
   await expect(terminal.locator(".openidea-terminal-selection-match:visible")).toHaveCount(0);
+
+  // Full-scrollback trim shifts a visible match into the cached margin row above viewportY; scrolling up must highlight it.
+  await page.evaluate(async () => {
+    const path = "/src/features/terminal/runtime.ts";
+    const { activeSession } = await import(path);
+    const s = activeSession()!;
+    const rows = s.term.rows;
+    s.term.options.scrollback = 4;
+    s.term.reset();
+    const total = rows + 4;
+    let payload = "";
+    for (let i = 0; i < total - 1; i++) {
+      payload += `${i === 4 ? "needle hit" : `row-${i}`}\r\n`;
+    }
+    payload += "needle sel";
+    await new Promise<void>((resolve) => s.term.write(payload, resolve));
+    s.term.select(0, total - 1, 6);
+  });
+  await expect(terminal.locator(".openidea-terminal-selection-match:visible")).toHaveCount(1);
+
+  await page.evaluate(async () => {
+    await new Promise((r) => setTimeout(r, 100));
+    const path = "/src/features/terminal/runtime.ts";
+    const { activeSession } = await import(path);
+    const s = activeSession()!;
+    await new Promise<void>((resolve) => s.term.write("\r\nnext", resolve));
+    s.term.scrollLines(-1);
+  });
+  await expect(terminal.locator(".openidea-terminal-selection-match:visible")).toHaveCount(1);
+  await expect(terminal.locator(".openidea-terminal-selection-match:visible")).toHaveCSS("top", "0px");
 });
 
 test("terminal ⌘F highlights active/inactive search matches and seeds with a new selection", async ({

fixtures/README.md

@@ -15,6 +15,7 @@ something to show.
 | `java-app/`      | JDK 21, Maven 3.9                                               | `mvn compile exec:java`             | `mvn test`           | `mvn test -DopenideaFail=true`            | unused variable in `App.java`                            |
 | `c-app/`         | gcc / g++ 12+, make, GDB 14+                                    | `make all`                          | —                    | —                                     | —                                                        |
 | `php-app/`       | PHP 8.5, Composer                                               | `composer quote`                    | `vendor/bin/pest`    | `OPENIDEA_FAIL=1 vendor/bin/pest`         | unused variable in `ThresholdCustoms.php`                |
+| `django-app/`    | Python 3.10+, Django 5.2+                                       | `python manage.py runserver`        | `python manage.py test` | `OPENIDEA_FAIL=1 python manage.py test` | unused import in `shop/views.py`                         |
 | `polyglot/`      | Go, TS, Python, C, shell, SQL, TOML/YAML/JSON, proto, Terraform | `make`                              | `make test`          | —                                     | unused variable in `native/hash.c`                       |
 
 The fixtures are standalone: `rust-app` declares its own `[workspace]` and

fixtures/django-app/config/settings.py

@@ -0,0 +1,27 @@
+"""Settings of the shop fixture: one app, no database tables of its own."""
+
+from pathlib import Path
+
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+SECRET_KEY = "fixture-only-not-a-secret"
+DEBUG = True
+ALLOWED_HOSTS = ["localhost", "127.0.0.1"]
+
+INSTALLED_APPS = ["django.contrib.staticfiles", "shop"]
+
+ROOT_URLCONF = "config.urls"
+
+TEMPLATES = [
+    {
+        "BACKEND": "django.template.backends.django.DjangoTemplates",
+        "DIRS": [],
+        "APP_DIRS": True,
+        "OPTIONS": {"context_processors": ["django.template.context_processors.request"]},
+    }
+]
+
+DATABASES = {"default": {"ENGINE": "django.db.backends.sqlite3", "NAME": ":memory:"}}
+
+STATIC_URL = "static/"
+USE_TZ = True

fixtures/django-app/config/urls.py

@@ -0,0 +1,3 @@
+from django.urls import include, path
+
+urlpatterns = [path("", include("shop.urls"))]

fixtures/django-app/manage.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+"""Django's command-line utility for the shop fixture."""
+
+import os
+import sys
+
+
+def main() -> None:
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings")
+    from django.core.management import execute_from_command_line
+
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == "__main__":
+    main()

fixtures/django-app/pages/promo.html

@@ -0,0 +1,4 @@
+<!-- Not in a templates folder: the editor offers Django Template from its tags. -->
+{% load static %}
+<p>Two cappuccini for <strong>{{ price|default:"€3" }}</strong></p>
+<img src="{% static 'promo.png' %}" alt="">

fixtures/django-app/requirements.txt

@@ -0,0 +1 @@
+Django>=5.2

fixtures/django-app/shop/templates/shop/base.html

@@ -0,0 +1,15 @@
+{% load static %}<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <title>{% block title %}Shop{% endblock %}</title>
+    <link rel="stylesheet" href="{% static 'shop/site.css' %}">
+  </head>
+  <body>
+    {# The navigation is the same on every page. #}
+    <nav><a href="{% url 'shop:products' %}">Menu</a></nav>
+    <main>
+      {% block content %}{% endblock content %}
+    </main>
+  </body>
+</html>

fixtures/django-app/shop/templates/shop/email/order.txt

@@ -0,0 +1,3 @@
+{% autoescape off %}Thank you for your order, {{ name|default:"customer" }}!
+{% for line in lines %}- {{ line.quantity }} × {{ line.product.name }}
+{% endfor %}{% endautoescape %}

fixtures/django-app/shop/templates/shop/product_list.html

@@ -0,0 +1,25 @@
+{% extends "shop/base.html" %}
+
+{% block title %}{% if single %}{{ products.0.name }}{% else %}Menu{% endif %} · {{ block.super }}{% endblock %}
+
+{% block content %}
+  <ul class="products">
+    {% for product in products %}
+      <li class="{% cycle 'odd' 'even' %}">
+        <a href="{% url 'shop:product' slug=product.slug %}">{{ product.name|title }}</a>
+        <span class="price">€{{ product.price|floatformat:2 }}</span>
+        {% with count=product.tags|length %}
+          {% if count > 1 %}
+            <small>{{ product.tags|join:", " }}</small>
+          {% endif %}
+        {% endwith %}
+      </li>
+    {% empty %}
+      <li>Nothing on the menu today.</li>
+    {% endfor %}
+  </ul>
+  {% comment "Ideas" %}
+    <p>{{ seasonal_specials }}</p>
+  {% endcomment %}
+  {% verbatim %}<script type="text/x-template">{{ clientSide }}</script>{% endverbatim %}
+{% endblock content %}

fixtures/django-app/shop/tests.py

@@ -0,0 +1,22 @@
+import os
+import unittest
+
+from django.test import SimpleTestCase
+from django.urls import reverse
+
+
+class ProductPagesTests(SimpleTestCase):
+    def test_lists_every_product(self):
+        response = self.client.get(reverse("shop:products"))
+        self.assertContains(response, "Espresso")
+        self.assertContains(response, "Cornetto")
+        self.assertContains(response, "€1.60")
+
+    def test_unknown_product_is_not_found(self):
+        response = self.client.get(reverse("shop:product", args=["tea"]))
+        self.assertEqual(response.status_code, 404)
+
+    @unittest.skipUnless(os.environ.get("OPENIDEA_FAIL"), "opt-in failing test")
+    def test_intentionally_failing(self):
+        # FIXME: the opt-in failing test, for the test runner's failure views.
+        self.assertContains(self.client.get(reverse("shop:products")), "Tea")

fixtures/django-app/shop/urls.py

@@ -0,0 +1,10 @@
+from django.urls import path
+
+from . import views
+
+app_name = "shop"
+
+urlpatterns = [
+    path("", views.product_list, name="products"),
+    path("products/<slug:slug>/", views.product_detail, name="product"),
+]

fixtures/django-app/shop/views.py

@@ -0,0 +1,35 @@
+"""Views of the shop: a product list and a product page."""
+
+import json  # Intentional warning: unused import.
+from dataclasses import dataclass
+from decimal import Decimal
+
+from django.http import Http404, HttpRequest, HttpResponse
+from django.shortcuts import render
+
+
+@dataclass(frozen=True)
+class Product:
+    slug: str
+    name: str
+    price: Decimal
+    tags: tuple[str, ...] = ()
+
+
+PRODUCTS = [
+    Product("espresso", "Espresso", Decimal("1.20"), ("coffee", "hot")),
+    Product("cappuccino", "Cappuccino", Decimal("1.60"), ("coffee", "milk")),
+    Product("cornetto", "Cornetto", Decimal("1.30")),
+]
+
+
+def product_list(request: HttpRequest) -> HttpResponse:
+    # TODO: paginate once the menu grows.
+    return render(request, "shop/product_list.html", {"products": PRODUCTS})
+
+
+def product_detail(request: HttpRequest, slug: str) -> HttpResponse:
+    product = next((p for p in PRODUCTS if p.slug == slug), None)  # Set a breakpoint here
+    if product is None:
+        raise Http404(slug)
+    return render(request, "shop/product_list.html", {"products": [product], "single": True})

java/java-usages/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: OpenIDEA Java usages
 Bundle-SymbolicName: ai.openidea.usages;singleton:=true
-Bundle-Version: 1.12.0
+Bundle-Version: 1.13.0
 Bundle-RequiredExecutionEnvironment: JavaSE-21
 Require-Bundle: org.eclipse.jdt.ls.core,org.eclipse.jdt.core,
  org.eclipse.jdt.core.manipulation,org.eclipse.core.runtime,

java/java-usages/README.md

@@ -88,7 +88,7 @@ is not a claim of full IntelliJ feature parity.
 ## Rebuild and delivery
 
 The checked-in jar is embedded by ide-sdk `include_bytes!`, installed as
-`java-usages-1.12.0.jar`, and added alongside existing initialization bundles.
+`java-usages-1.13.0.jar`, and added alongside existing initialization bundles.
 Users need no compiler, Maven or Python. Manifest/install version must change
 when replacing the bundle because OSGi caches bundles.