fix(project-view): paste a clipboard image as img.png

Pasting into the Project view only handled files, so a screenshot on the
clipboard did nothing. With no files to paste, Paste now saves the clipboard
image in the target folder as img.png (img_1.png, img_2.png ... when taken)
and selects it; Paste is enabled while the clipboard holds an image.

The image is read natively: public.png, or public.tiff converted, on macOS;
the registered PNG format, or CF_DIB (24/32-bit) encoded as PNG, on Windows;
GTK on Linux as before.

Fixes #3486

Cargo.lock

@@ -4232,6 +4232,7 @@ dependencies = [
  "objc2 0.6.5",
  "objc2-app-kit 0.3.2",
  "objc2-foundation 0.3.2",
+ "png 0.18.1",
 ]
 
 [[package]]

crates/ide-agent/src/lib.rs

@@ -283,6 +283,11 @@ struct TaskFile {
     /// The folder (in the task store) with copies of the `before` files, for rolling back.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     saved: Option<String>,
+    /// In the project's own checkout, where the user and other tasks change files too: the
+    /// files that changed while one of this task's turns ran, the only ones its changes list.
+    /// `None` for a worktree task, and a task saved before these were recorded.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    touched: Option<BTreeSet<String>>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     subagents: Vec<SavedSubagent>,
     /// Turns to drop from the session once it is loaded (a fork of an earlier point).
@@ -293,6 +298,9 @@ struct TaskFile {
     title_renamed: bool,
 }
 
+/// The changed files of a checkout, stamped.
+type Snapshot = BTreeMap<String, worktree::Stamp>;
+
 struct TaskState {
     task: AgentTask,
     session_id: Option<String>,
@@ -300,11 +308,18 @@ struct TaskState {
     wanted: Vec<AgentConfigChoice>,
     before: Arc<BTreeMap<String, worktree::Stamp>>,
     saved: Option<String>,
+    /// See `TaskFile::touched`.
+    touched: Option<Arc<BTreeSet<String>>>,
     pending_rollback: u32,
     /// The user named the task; see `TaskFile::title_renamed`.
     title_renamed: bool,
     /// A turn is running or about to (prompts arriving now are queued).
     busy: bool,
+    /// A temporary side conversation: lives in memory only, never persisted.
+    ephemeral: bool,
+    /// The conversation a temporary side conversation starts with, sent to the agent with
+    /// its first real message; the task's own entries hold only the questions.
+    ephemeral_context: Option<String>,
     /// Background tasks the agent reported as running (`run_in_background` commands and
     /// the like), as it sent them: unlike a turn they outlive it, so an idle release
     /// waits for the last one. A (re)started process runs nothing yet.
@@ -424,8 +439,14 @@ impl AgentManager {
     }
 
     /// Routes events to `sink` (replacing the previous subscriber); returns every task.
+    /// Ephemeral tasks belonged to the previous page session: a fresh one starts without them.
     pub fn subscribe(&self, sink: AgentSink) -> Vec<AgentTask> {
         *self.shared.sink.write() = Some(sink);
+        let stale: Vec<Arc<Task>> = self.tasks.read().values().filter(|t| t.state.lock().ephemeral).cloned().collect();
+        for task in &stale {
+            self.drop_in_memory(task);
+            self.shared.emit(AgentEvent::Removed { id: task.id.clone() });
+        }
         let mut tasks: Vec<AgentTask> = self.tasks.read().values().map(|t| t.state.lock().task.clone()).collect();
         tasks.sort_by(|a, b| b.updated_ms.total_cmp(&a.updated_ms));
         tasks
@@ -655,19 +676,18 @@ impl AgentManager {
             retry: None,
             background: Box::default(),
         };
-        let file = TaskFile {
+        let handle = self.register(TaskFile {
             task: task.clone(),
             session_id: Some(session_id.to_owned()),
             entries: Vec::new(),
             wanted: Vec::new(),
             before: BTreeMap::new(),
             saved: None,
+            touched: Some(BTreeSet::new()),
             subagents: Vec::new(),
             pending_rollback: 0,
             title_renamed: true,
-        };
-        let handle = Task::restore(file, self.shared.clone());
-        self.tasks.write().insert(task.id.clone(), handle.clone());
+        });
         handle.emit_task();
         handle.persist();
         Ok(task)
@@ -705,27 +725,8 @@ impl AgentManager {
                 (root, None, base, commit, before)
             }
         };
-        // Until the session reports its own, show what the agent offered last time with the choices applied.
-        let catalog = self.shared.paths.catalogs.cached(&self.shared, &spec.id);
-        let mut levels = catalog.thought_levels;
-        let mut config = self.shared.config_for_new_task(catalog.config, &spec.id);
-        for choice in &req.config {
-            if let Some(o) = config.iter_mut().find(|o| o.id == choice.id) {
-                o.current = Some(choice.value.clone());
-            }
-        }
-        if let Some(model) = model_of(&config)
-            && let Some(levels) = levels.remove(&model)
-        {
-            config.extend(levels.into_iter().map(|mut o| {
-                if let Some(choice) =
-                    req.config.iter().find(|c| c.id == o.id && o.values.iter().any(|v| v.value == c.value))
-                {
-                    o.current = Some(choice.value.clone());
-                }
-                o
-            }));
-        }
+        // The session's settings: what the agent offered last time, with the choices applied.
+        let config = self.merged_config(&spec.id, &req.config);
         let now = now_ms();
         let id = uuid::Uuid::new_v4().simple().to_string();
         // Copies of the files the user had changed already, for rolling back the task's changes to them.
@@ -766,26 +767,128 @@ impl AgentManager {
             retry: None,
             background: Box::default(),
         };
-        let file = TaskFile {
+        let handle = self.register(TaskFile {
             task: task.clone(),
             session_id: None,
             entries: Vec::new(),
             wanted: req.config,
             before,
             saved,
+            touched: (req.isolation == Isolation::Local).then(BTreeSet::new),
             subagents: Vec::new(),
             pending_rollback: 0,
             title_renamed: false,
-        };
-        let handle = Task::restore(file, self.shared.clone());
+        });
         handle.state.lock().busy = true;
-        self.tasks.write().insert(task.id.clone(), handle.clone());
-        handle.emit_task();
         handle.persist();
         self.shared.runtime.spawn(async move { handle.run(prompt).await });
         Ok(task)
     }
 
+    /// Builds the in-memory handle of a fresh task, registers it and announces it. The
+    /// caller decides what else its life starts with (a persisted file, a session, a run).
+    fn register(&self, file: TaskFile) -> Arc<Task> {
+        let handle = Task::restore(file, self.shared.clone());
+        self.tasks.write().insert(handle.id.clone(), handle.clone());
+        handle.emit_task();
+        handle
+    }
+
+    /// The session's settings: what the agent offered last time, with the request's
+    /// choices — and the chosen model's thought levels — applied.
+    fn merged_config(&self, provider: &str, req: &[AgentConfigChoice]) -> Vec<AgentConfigOption> {
+        let catalog = self.shared.paths.catalogs.cached(&self.shared, provider);
+        let mut levels = catalog.thought_levels;
+        let mut config = self.shared.config_for_new_task(catalog.config, provider);
+        for choice in req {
+            if let Some(o) = config.iter_mut().find(|o| o.id == choice.id) {
+                o.current = Some(choice.value.clone());
+            }
+        }
+        if let Some(model) = model_of(&config)
+            && let Some(levels) = levels.remove(&model)
+        {
+            config.extend(levels.into_iter().map(|mut o| {
+                if let Some(choice) = req.iter().find(|c| c.id == o.id && o.values.iter().any(|v| v.value == c.value)) {
+                    o.current = Some(choice.value.clone());
+                }
+                o
+            }));
+        }
+        config
+    }
+
+    /// Creates a temporary side conversation of `source`: an in-memory task that is never
+    /// persisted, whose session starts with its first real message (`prompt` only names
+    /// the title). `source`'s conversation rides along as the context of that message.
+    /// The task is read-only: its settings are pushed to a mode that asks before anything,
+    /// and requests that would change the project are denied regardless. Fails for an
+    /// agent that offers no way to ask.
+    pub async fn create_ephemeral(&self, req: NewAgentTask, source: &str) -> IdeResult<AgentTask> {
+        let spec = self
+            .shared
+            .spec(&req.provider)
+            .ok_or_else(|| IdeError::invalid(format!("unknown agent {}", req.provider)))?;
+        let prompt = clean(req.prompt).ok_or_else(|| IdeError::invalid("describe the topic first"))?;
+        let title = title_of(&prompt);
+        let mut config = self.merged_config(&spec.id, &req.config);
+        config::ask_for_approvals(&mut config);
+        if config::bypass_approvals(&config) {
+            return Err(IdeError::invalid(
+                "this agent has no mode that asks before changing things, so it can't run a side conversation",
+            ));
+        }
+        let read_only = !config::bypass_approvals(&config);
+        let context = context_transcript(&self.task(source)?.state.lock().conversation.main.entries);
+        let root = self.shared.paths.project_root.clone();
+        let before = blocking(move || Ok(worktree::snapshot(&root).unwrap_or_default())).await?;
+        let now = now_ms();
+        let mut capabilities = self.shared.probes.lock().get(&spec.id).map(|p| p.capabilities).unwrap_or_default();
+        capabilities.read_only = read_only;
+        let task = AgentTask {
+            project_root: Some(IpcPath(self.shared.paths.project_root.clone())),
+            id: uuid::Uuid::new_v4().simple().to_string(),
+            title,
+            provider: spec.id.clone(),
+            model: model_of(&config),
+            status: AgentStatus::Ready,
+            isolation: Isolation::Local,
+            cwd: IpcPath(self.shared.paths.project_root.clone()),
+            branch: None,
+            base: None,
+            base_commit: None,
+            error: None,
+            created_ms: now,
+            updated_ms: now,
+            commands: self.shared.known_commands(&spec.id),
+            usage: None,
+            queue: Vec::new(),
+            capabilities,
+            resets_ms: None,
+            retry: None,
+            background: Box::default(),
+            config,
+        };
+        let handle = self.register(TaskFile {
+            task: task.clone(),
+            session_id: None,
+            entries: Vec::new(),
+            wanted: req.config,
+            before,
+            saved: None,
+            touched: None,
+            subagents: Vec::new(),
+            pending_rollback: 0,
+            title_renamed: false,
+        });
+        {
+            let mut s = handle.state.lock();
+            s.ephemeral = true;
+            s.ephemeral_context = Some(context);
+        }
+        Ok(task)
+    }
+
     /// Sends a message. While the agent works it is queued, or with `now` the current turn
     /// is cancelled and the message goes next.
     pub async fn prompt(&self, id: &str, prompt: AgentPrompt, now: bool) -> IdeResult<()> {
@@ -1006,6 +1109,7 @@ impl AgentManager {
                 wanted: s.wanted.clone(),
                 before: (*s.before).clone(),
                 saved: s.saved.clone(),
+                touched: s.touched.as_deref().cloned(),
                 subagents: s.conversation.saved_subagents(),
                 pending_rollback: total - keep,
                 title_renamed: s.title_renamed,
@@ -1205,6 +1309,15 @@ impl AgentManager {
         Ok(())
     }
 
+    /// Removes a task from the manager's table and stops its agent. The disk (its file,
+    /// its worktree) is the caller's business.
+    fn drop_in_memory(&self, task: &Arc<Task>) {
+        task.kill();
+        self.tasks.write().remove(&task.id);
+        *task.deleted.lock() = true;
+        let _ = std::fs::remove_file(self.shared.paths.store_dir.join(format!("{}.json", task.id)));
+    }
+
     /// Returns an archived task to the active list without starting the agent.
     pub fn unarchive(&self, id: &str) -> IdeResult<()> {
         let task = self.task(id)?;
@@ -1288,8 +1401,8 @@ impl AgentManager {
     pub async fn changes(&self, id: &str) -> IdeResult<Vec<AgentChange>> {
         let task = self.task(id)?;
         let at = task.base();
-        let before = task.state.lock().before.clone();
-        blocking(move || at.changes(&before)).await
+        let (before, touched) = task.attribution();
+        blocking(move || Ok(worktree::made_by_task(at.changes(&before)?, touched.as_deref()))).await
     }
 
     /// The task's uncommitted changes and, for a worktree task, the commits made since it
@@ -1297,8 +1410,13 @@ impl AgentManager {
     pub async fn grouped_changes(&self, id: &str) -> IdeResult<AgentChanges> {
         let task = self.task(id)?;
         let at = task.base();
-        let before = task.state.lock().before.clone();
-        blocking(move || at.grouped_changes(&before)).await
+        let (before, touched) = task.attribution();
+        blocking(move || {
+            let mut grouped = at.grouped_changes(&before)?;
+            grouped.uncommitted = worktree::made_by_task(grouped.uncommitted, touched.as_deref());
+            Ok(grouped)
+        })
+        .await
     }
 
     /// Content of `path` (in the task's directory) when the task started.
@@ -1324,15 +1442,16 @@ impl AgentManager {
             return Err(IdeError::invalid("the agent is working: stop it before rolling back its changes"));
         }
         let at = task.base();
-        let (before, saved) = {
+        let (before, saved, touched) = {
             let s = task.state.lock();
-            (s.before.clone(), s.saved.as_ref().map(|name| self.shared.paths.store_dir.join(name)))
+            (s.before.clone(), s.saved.as_ref().map(|name| self.shared.paths.store_dir.join(name)), s.touched.clone())
         };
         let restamped = blocking(move || {
             let (changes, rev) = match view {
                 AgentChangesView::Group => (at.grouped_changes(&before)?.uncommitted, worktree::head_commit(at.cwd())?),
                 AgentChangesView::SinceStart => (at.changes(&before)?, at.rev()?),
             };
+            let changes = worktree::made_by_task(changes, touched.as_deref());
             let sources = match rev.as_deref() {
                 Some(rev) => worktree::rename_sources(at.cwd(), rev)?,
                 None => Default::default(),
@@ -1423,9 +1542,12 @@ impl Task {
                 wanted: file.wanted,
                 before: Arc::new(file.before),
                 saved: file.saved,
+                touched: file.touched.map(Arc::new),
                 pending_rollback: file.pending_rollback,
                 title_renamed: file.title_renamed,
                 busy: false,
+                ephemeral: false,
+                ephemeral_context: None,
                 background_tasks: Vec::new(),
             }),
             live: Mutex::new(None),
@@ -1447,6 +1569,41 @@ impl Task {
         })
     }
 
+    /// The files already changed when the task started, and the files its turns changed.
+    fn attribution(&self) -> (Arc<Snapshot>, Option<Arc<BTreeSet<String>>>) {
+        let s = self.state.lock();
+        (s.before.clone(), s.touched.clone())
+    }
+
+    /// The changed files of the checkout as a turn starts, when the task records what its turns change.
+    async fn checkout_before_turn(&self) -> Option<Snapshot> {
+        let cwd = {
+            let s = self.state.lock();
+            s.touched.as_ref()?;
+            s.task.cwd.0.clone()
+        };
+        blocking(move || worktree::snapshot(&cwd)).await.ok()
+    }
+
+    /// Records the files that changed in the checkout since `start`, as the turn ends, as the task's.
+    async fn record_turn_changes(&self, start: Option<Snapshot>) {
+        let Some(start) = start else { return };
+        let cwd = self.state.lock().task.cwd.0.clone();
+        let Ok(end) = blocking(move || worktree::snapshot(&cwd)).await else { return };
+        let changed = worktree::changed_between(&start, &end);
+        if changed.is_empty() {
+            return;
+        }
+        {
+            let mut s = self.state.lock();
+            let Some(touched) = &s.touched else { return };
+            let mut touched = (**touched).clone();
+            touched.extend(changed);
+            s.touched = Some(Arc::new(touched));
+        }
+        self.persist();
+    }
+
     fn base(&self) -> worktree::TaskBase {
         let s = self.state.lock();
         let cwd = s.task.cwd.0.clone();
@@ -1527,6 +1684,9 @@ impl Task {
         if *deleted {
             return;
         }
+        if self.state.lock().ephemeral {
+            return;
+        }
         let bytes = {
             let s = self.state.lock();
             serde_json::to_vec(&TaskFile {
@@ -1536,6 +1696,7 @@ impl Task {
                 wanted: s.wanted.clone(),
                 before: (*s.before).clone(),
                 saved: s.saved.clone(),
+                touched: s.touched.as_deref().cloned(),
                 subagents: s.conversation.saved_subagents(),
                 pending_rollback: s.pending_rollback,
                 title_renamed: s.title_renamed,
@@ -1587,9 +1748,11 @@ impl Task {
     /// the user stops one. The caller set `busy`.
     async fn run(self: Arc<Self>, mut prompt: AgentPrompt) {
         loop {
+            let start = self.checkout_before_turn().await;
             let result = self.turn(&prompt).await;
             self.cancel_pending.store(false, Ordering::Release);
             tokio::time::sleep(TURN_GRACE).await;
+            self.record_turn_changes(start).await;
             let changed = self.state.lock().conversation.end_turn(Some(now_ms()));
             self.mark_dirty(changed);
             let send_now = self.send_now.swap(false, Ordering::AcqRel);
@@ -1757,7 +1920,20 @@ impl Task {
         if !prompt.images.is_empty() && !live.capabilities.images {
             return Err(Failure::from("This agent can't read images.".to_owned()));
         }
-        let content = self.content(&live, prompt).await;
+        // A temporary side conversation's context rides with its first real message; the
+        // conversation itself records only the question (and whatever comes after).
+        let prompt = {
+            let context = self.state.lock().ephemeral_context.take();
+            match context {
+                Some(context) => {
+                    let mut owned = prompt.clone();
+                    owned.text = format!("{context}\n\n---\n\n{}", owned.text);
+                    owned
+                }
+                None => prompt.clone(),
+            }
+        };
+        let content = self.content(&live, &prompt).await;
         let result: Result<Value, RpcError> =
             live.peer.request("session/prompt", json!({ "sessionId": live.session, "prompt": content }), None).await;
         match result {
@@ -2211,6 +2387,29 @@ impl Task {
                     .collect()
             })
             .unwrap_or_default();
+        // A side conversation is read-only: deny anything that would change the project
+        // (its task is deleted when its pane closes, leaving nothing to review or revert).
+        if self.state.lock().ephemeral
+            && params
+                .pointer("/toolCall/kind")
+                .or_else(|| params.pointer("/subject/toolCall/kind"))
+                .and_then(Value::as_str)
+                .is_some_and(|kind| matches!(kind, "edit" | "delete" | "move" | "execute"))
+        {
+            let reject = options.iter().find(|o| o.kind.starts_with("reject")).cloned();
+            let _ = self.push_entry(AgentEntry::Permission {
+                id,
+                title,
+                command: None,
+                options,
+                questions: Vec::new(),
+                chosen: Some("Denied: side conversations are read-only".to_owned()),
+            });
+            return match reject {
+                Some(option) => json!({ "outcome": { "outcome": "selected", "optionId": option.id } }),
+                None => json!({ "outcome": { "outcome": "cancelled" } }),
+            };
+        }
         let asked: Vec<String> = questions
             .iter()
             .map(|question| question.answer_key.clone().unwrap_or_else(|| question.question.clone()))
@@ -2408,6 +2607,72 @@ fn clean(mut prompt: AgentPrompt) -> Option<AgentPrompt> {
     (!prompt.text.is_empty() || !prompt.images.is_empty() || !prompt.files.is_empty()).then_some(prompt)
 }
 
+/// The character budget of a side conversation's context: the newest entries win, the
+/// oldest are dropped first. Leaves room for the question and the agent's answer.
+const CONTEXT_BUDGET: usize = 100_000;
+
+/// A long tool output trimmed to its first and last few lines, with the elided middle noted.
+fn trimmed_output(output: &str) -> String {
+    const KEPT: usize = 4;
+    let lines: Vec<&str> = output.lines().collect();
+    if lines.len() <= KEPT * 2 + 1 {
+        return output.to_owned();
+    }
+    let omitted = lines.len() - KEPT * 2;
+    let mut out = lines[..KEPT].join("\n");
+    out.push_str(&format!("\n… {omitted} lines omitted …\n"));
+    out.push_str(&lines[lines.len() - KEPT..].join("\n"));
+    out
+}
+
+fn context_entry(e: &AgentEntry) -> Option<String> {
+    match e {
+        AgentEntry::User { text, .. } => Some(format!("User: {text}")),
+        AgentEntry::Agent { text, .. } if !text.trim().is_empty() => Some(format!("Agent: {text}")),
+        AgentEntry::Thought { text, .. } if !text.trim().is_empty() => Some(format!("Thought: {text}")),
+        AgentEntry::Tool { title, output, .. } => match output.as_deref() {
+            Some(output) if !output.trim().is_empty() => Some(format!("Tool: {title}\n{}", trimmed_output(output))),
+            _ => Some(format!("Tool: {title}")),
+        },
+        AgentEntry::Error { message, .. } => Some(format!("Error: {message}")),
+        _ => None,
+    }
+}
+
+/// The conversation as the context a temporary side conversation starts with: what was
+/// said, what was done (tool calls with trimmed output), errors and the agent's reasoning,
+/// oldest first, within [`CONTEXT_BUDGET`].
+fn context_transcript(entries: &[AgentEntry]) -> String {
+    // Newest wins: walk back until the budget is spent, dropping the oldest entries first.
+    let mut lines: Vec<String> = Vec::new();
+    let mut used = 0usize;
+    for e in entries.iter().rev() {
+        let Some(line) = context_entry(e) else { continue };
+        if used + line.len() > CONTEXT_BUDGET {
+            if lines.is_empty() {
+                // Even the newest entry alone exceeds the budget: keep its head.
+                lines.push(line.chars().take(CONTEXT_BUDGET).collect());
+            }
+            break;
+        }
+        used += line.len();
+        lines.push(line);
+    }
+    lines.reverse();
+    let dropped = entries.iter().rev().filter_map(context_entry).count() - lines.len();
+    let mut context = String::from(
+        "You are answering a side question in a temporary conversation. The conversation so far is below, \
+         for context only; answer the new question after the marker, and do not continue the main task \
+         unless asked.\n\n<conversation>\n",
+    );
+    if dropped > 0 {
+        context.push_str(&format!("(The {dropped} oldest entries are omitted.)\n\n"));
+    }
+    context.push_str(&lines.join("\n\n"));
+    context.push_str("\n</conversation>");
+    context
+}
+
 fn permission_title(params: &Value) -> String {
     let call = &params["toolCall"];
     let title = call.get("title").and_then(Value::as_str).filter(|t| !t.is_empty());
@@ -2608,6 +2873,7 @@ fn capabilities_of(init: &acp::Negotiated) -> (AgentCapabilities, bool) {
         rollback: meta("/openidea/rollback"),
         steer: meta("/openidea/steer"),
         background_tasks: meta("/openidea/backgroundTasks"),
+        read_only: false,
     };
     (capabilities, init.prompt("embeddedContext"))
 }

crates/ide-agent/src/model.rs

@@ -36,6 +36,9 @@ pub struct AgentCapabilities {
     pub steer: bool,
     /// It reports its background tasks and stops them one by one.
     pub background_tasks: bool,
+    /// The task runs read-only: it asks before anything, and requests that would change
+    /// the project are denied (a temporary side conversation).
+    pub read_only: bool,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]

crates/ide-agent/src/tests.rs

@@ -2211,6 +2211,7 @@ async fn task_project_root_controls_local_and_worktree_repositories() {
             .unwrap();
         mgr.respond(&task.id, permission, Some("yes".into())).unwrap();
         wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+        count_every_change(&mgr, &task.id);
         assert_eq!(task.project_root, Some(IpcPath(member.clone())));
         assert_eq!(task.base.as_deref(), Some("member-main"));
         if isolation == Isolation::Local {
@@ -2842,12 +2843,14 @@ async fn rolling_back_restores_the_start_of_the_task_and_keeps_the_users_own_edi
         .await
         .unwrap();
     wait_for(&mgr, &task.id, AgentStatus::NeedsInput).await;
-    mgr.cancel(&task.id, None).unwrap();
-    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
-    // What the agent did.
+    // What the agent did, while its turn ran.
     write("mine.txt", "my edit\nand the agent's\n");
     write("other.txt", "agent\n");
     write("new.txt", "agent\n");
+    mgr.cancel(&task.id, None).unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    // The user's (or another task's) work between turns is not the task's.
+    write("later.txt", "mine\n");
     async fn changed(mgr: &AgentManager, id: &str) -> Vec<String> {
         mgr.changes(id).await.unwrap().into_iter().map(|c| c.rel_path).collect()
     }
@@ -2863,6 +2866,7 @@ async fn rolling_back_restores_the_start_of_the_task_and_keeps_the_users_own_edi
     mgr.rollback_changes(&task.id, None, AgentChangesView::SinceStart).await.unwrap();
     assert_eq!(read("mine.txt"), "my edit\n", "the user's edit stays");
     assert!(!dir.join("new.txt").exists());
+    assert_eq!(read("later.txt"), "mine\n", "not the task's to roll back");
     assert!(changed(&mgr, &task.id).await.is_empty());
 
     mgr.delete(&task.id, false).await.unwrap();
@@ -2947,10 +2951,17 @@ impl Checkout {
         wait_for(&mgr, &task.id, AgentStatus::NeedsInput).await;
         mgr.cancel(&task.id, None).unwrap();
         wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+        count_every_change(&mgr, &task.id);
         (mgr, task)
     }
 }
 
+/// Counts every change in the checkout as the task's, as for a task saved before tasks
+/// recorded what their turns changed: for tests that change files outside a turn.
+fn count_every_change(mgr: &AgentManager, id: &str) {
+    mgr.task(id).unwrap().state.lock().touched = None;
+}
+
 async fn changed(mgr: &AgentManager, id: &str) -> Vec<String> {
     mgr.changes(id).await.unwrap().into_iter().map(|c| c.rel_path).collect()
 }
@@ -3227,3 +3238,192 @@ async fn security_policy_never_auto_approves_a_request_that_only_reads_like_a_co
         "{entries:?}"
     );
 }
+
+/// A temporary side conversation is created ready, without starting its session and
+/// without writing anything to the store; a fresh subscriber (a reloaded page) sweeps
+/// it, and deleting it just drops it from memory.
+#[tokio::test(flavor = "multi_thread")]
+async fn ephemeral_tasks_stay_in_memory_only() {
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent.clone());
+    let source = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("hello"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &source.id, AgentStatus::NeedsInput).await;
+    let calls_before = agent.calls.lock().len();
+    let task = mgr
+        .create_ephemeral(
+            NewAgentTask {
+                project_root: None,
+                prompt: text("What changed in this file?"),
+                provider: "claude".into(),
+                config: vec![],
+                isolation: Isolation::Local,
+                base: None,
+            },
+            &source.id,
+        )
+        .await
+        .unwrap();
+    // Registering it starts nothing: the session waits for its first real message.
+    assert_eq!(agent.calls.lock().len(), calls_before);
+    assert_eq!(mgr.task(&task.id).unwrap().state.lock().task.status, AgentStatus::Ready);
+    assert!(!tmp.path().join("store").join(format!("{}.json", task.id)).exists());
+
+    // Its first message starts the session like any task's, and still saves nothing: the
+    // conversation records the question, not the context that rode along to the agent.
+    // The fake agent's turn asks to change something, which a side conversation denies by
+    // itself, so the turn ends without waiting for the user.
+    mgr.prompt(&task.id, text("Why?"), false).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    let entries = mgr.entries(&task.id, None).unwrap();
+    let question = entries.iter().find_map(|e| match e {
+        AgentEntry::User { text, .. } => Some(text.clone()),
+        _ => None,
+    });
+    assert_eq!(question.as_deref(), Some("Why?"));
+    assert!(
+        entries.iter().any(|e| matches!(e, AgentEntry::Permission { chosen: Some(c), .. } if c.contains("read-only"))),
+        "its `cargo test` request was denied: {entries:?}"
+    );
+    assert!(!tmp.path().join("store").join(format!("{}.json", task.id)).exists());
+
+    // A fresh subscriber (a reloaded page) sweeps it: it never reaches the task list.
+    let events: Arc<Mutex<Vec<AgentEvent>>> = Arc::new(Mutex::new(Vec::new()));
+    let sink_events = events.clone();
+    let tasks = mgr.subscribe(Arc::new(move |e| sink_events.lock().push(e)));
+    assert!(!tasks.iter().any(|t| t.id == task.id));
+    assert!(mgr.task(&task.id).is_err());
+    assert!(events.lock().iter().any(|e| matches!(e, AgentEvent::Removed { id } if *id == task.id)));
+    mgr.shutdown();
+}
+
+/// A side conversation's context stays within its budget: long tool outputs are cut to
+/// their head and tail, and entries that no longer fit are dropped oldest first.
+#[test]
+fn side_conversation_context_is_bounded() {
+    let long_output = (0..400).map(|i| format!("line {i}")).collect::<Vec<_>>().join(
+        "
+",
+    );
+    // Each reply alone is well inside the budget; together they are past it.
+    let reply = |n: usize| AgentEntry::Agent { text: format!("reply {n} {}", "x".repeat(30_000)) };
+    let entries = vec![
+        AgentEntry::User {
+            text: "oldest question".into(),
+            attachments: vec![],
+            images: vec![],
+            sent_ms: None,
+            done_ms: None,
+            steered: false,
+        },
+        reply(1),
+        reply(2),
+        reply(3),
+        reply(4),
+        AgentEntry::Tool {
+            id: "t1".into(),
+            title: "grep".into(),
+            kind: "search".into(),
+            status: AgentToolStatus::Completed,
+            locations: vec![],
+            output: Some(long_output),
+            diffs: vec![],
+        },
+        AgentEntry::User {
+            text: "newest question".into(),
+            attachments: vec![],
+            images: vec![],
+            sent_ms: None,
+            done_ms: None,
+            steered: false,
+        },
+    ];
+    let transcript = context_transcript(&entries);
+    assert!(transcript.contains("newest question"), "the newest entry is always kept");
+    assert!(transcript.contains("lines omitted"), "a long tool output is trimmed");
+    assert!(transcript.contains("line 0") && transcript.contains("line 399"), "its head and tail stay");
+    assert!(!transcript.contains("oldest question"), "entries past the budget are dropped oldest first");
+    assert!(transcript.contains("oldest entries are omitted"));
+}
+
+/// An ephemeral task denies a permission request that would change the project.
+#[tokio::test(flavor = "multi_thread")]
+async fn ephemeral_tasks_deny_write_permissions() {
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent.clone());
+    let source = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("Something with a conversation to reuse"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &source.id, AgentStatus::NeedsInput).await;
+    let pending = mgr
+        .entries(&source.id, None)
+        .unwrap()
+        .iter()
+        .find_map(|e| match e {
+            AgentEntry::Permission { id, chosen: None, .. } => Some(*id),
+            _ => None,
+        })
+        .unwrap_or_else(|| panic!("no pending permission request"));
+    mgr.respond(&source.id, pending, Some("no".into())).unwrap();
+    wait_for(&mgr, &source.id, AgentStatus::Ready).await;
+
+    let task = mgr
+        .create_ephemeral(
+            NewAgentTask {
+                project_root: None,
+                prompt: text("What changed in this file?"),
+                provider: "claude".into(),
+                config: vec![],
+                isolation: Isolation::Local,
+                base: None,
+            },
+            &source.id,
+        )
+        .await
+        .unwrap();
+    assert!(mgr.task(&task.id).unwrap().state.lock().task.capabilities.read_only);
+
+    let answer = mgr
+        .task(&task.id)
+        .unwrap()
+        .ask_permission(&json!({
+            "sessionId": "c1",
+            "toolCall": {"toolCallId": "c1-t2", "title": "Edit main.rs", "kind": "edit"},
+            "options": [
+                {"optionId": "yes", "name": "Allow", "kind": "allow_once"},
+                {"optionId": "no", "name": "Reject", "kind": "reject_once"}
+            ]
+        }))
+        .pointer("/outcome/optionId")
+        .and_then(Value::as_str)
+        .unwrap_or("none")
+        .to_owned();
+    assert_eq!(answer, "no", "the write request is denied");
+    let entries = mgr.entries(&task.id, None).unwrap();
+    assert!(
+        entries
+            .iter()
+            .any(|e| matches!(e, AgentEntry::Permission { chosen: Some(chosen), .. } if chosen.contains("read-only"))),
+        "{entries:?}"
+    );
+    mgr.shutdown();
+}

crates/ide-agent/src/worktree.rs

@@ -3,7 +3,7 @@
 use crate::model::{AgentChange, AgentChanges, AgentCommit};
 use ide_core::{IdeError, IdeResult, IpcPath};
 use ide_vcs::{ChangeKind, LogQuery, Repo};
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, BTreeSet};
 use std::path::{Path, PathBuf};
 use std::time::{Duration, UNIX_EPOCH};
 
@@ -548,6 +548,25 @@ pub(crate) fn snapshot(cwd: &Path) -> IdeResult<BTreeMap<String, Stamp>> {
     Ok(repo.status()?.into_iter().map(|s| (s.rel_path, stamp(&s.path))).collect())
 }
 
+/// The files whose state changed between two snapshots of a checkout: edited, new, deleted,
+/// or back to as committed.
+pub(crate) fn changed_between(start: &BTreeMap<String, Stamp>, end: &BTreeMap<String, Stamp>) -> Vec<String> {
+    let mut changed: Vec<String> =
+        end.iter().filter(|(path, stamp)| start.get(*path) != Some(*stamp)).map(|(path, _)| path.clone()).collect();
+    changed.extend(start.keys().filter(|path| !end.contains_key(*path)).cloned());
+    changed
+}
+
+/// The changes among `changes` that the task made, when it records the files its turns
+/// changed (`None`: every change counts).
+pub(crate) fn made_by_task(changes: Vec<AgentChange>, touched: Option<&BTreeSet<String>>) -> Vec<AgentChange> {
+    let Some(touched) = touched else { return changes };
+    changes
+        .into_iter()
+        .filter(|c| touched.contains(&c.rel_path) || c.old_path.as_ref().is_some_and(|old| touched.contains(old)))
+        .collect()
+}
+
 /// Drops the changes that were there before the task and haven't been touched since.
 pub(crate) fn without_untouched(changes: Vec<AgentChange>, before: &BTreeMap<String, Stamp>) -> Vec<AgentChange> {
     changes.into_iter().filter(|c| before.get(&c.rel_path).is_none_or(|s| *s != stamp(&c.path))).collect()
@@ -1184,4 +1203,20 @@ mod tests {
         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");
     }
+
+    #[test]
+    fn a_turn_changed_the_files_whose_state_moved() {
+        let start: BTreeMap<String, Stamp> =
+            [("edited", Some((1, 1))), ("same", Some((2, 2))), ("reverted", Some((3, 3)))]
+                .into_iter()
+                .map(|(p, s)| (p.to_owned(), s))
+                .collect();
+        let end: BTreeMap<String, Stamp> = [("edited", Some((1, 9))), ("same", Some((2, 2))), ("new", Some((4, 4)))]
+            .into_iter()
+            .map(|(p, s)| (p.to_owned(), s))
+            .collect();
+        let mut changed = changed_between(&start, &end);
+        changed.sort();
+        assert_eq!(changed, ["edited", "new", "reverted"]);
+    }
 }

crates/ide-clipboard/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ide-clipboard"
-description = "The OS clipboard's file list (Explorer <-> project view): Windows CF_HDROP or macOS NSPasteboard file URLs, no window or message loop"
+description = "The OS clipboard's file list (Explorer <-> project view) and pasted images: Windows CF_HDROP / PNG / CF_DIB or macOS NSPasteboard, no window or message loop"
 version.workspace = true
 edition.workspace = true
 license.workspace = true
@@ -9,8 +9,14 @@ license.workspace = true
 
 [target.'cfg(target_os = "macos")'.dependencies]
 objc2 = { version = "0.6", default-features = false, features = ["std"] }
-objc2-foundation = { version = "0.3", default-features = false, features = ["std", "NSArray", "NSDictionary", "NSEnumerator", "NSObject", "NSString", "NSURL", "NSValue"] }
-objc2-app-kit = { version = "0.3", default-features = false, features = ["std", "NSPasteboard"] }
+objc2-foundation = { version = "0.3", default-features = false, features = ["std", "NSArray", "NSData", "NSDictionary", "NSEnumerator", "NSObject", "NSString", "NSURL", "NSValue"] }
+objc2-app-kit = { version = "0.3", default-features = false, features = ["std", "NSBitmapImageRep", "NSImageRep", "NSPasteboard"] }
+
+[target.'cfg(windows)'.dependencies]
+png = "0.18"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 gtk = "0.18"
+
+[dev-dependencies]
+png = "0.18"

crates/ide-clipboard/src/lib.rs

@@ -18,6 +18,10 @@
 //!
 //! Other platforms (`text/uri-list` on X11) are not wired up: [`files`] is
 //! empty and [`set_files`] fails there.
+//!
+//! [`png`] reads an image (a screenshot) for the project view's Paste, which
+//! saves it as a file: `public.png` or `public.tiff` on macOS, the registered
+//! `PNG` format or `CF_DIB` on Windows. Linux reads it through GTK in the app.
 
 use std::path::PathBuf;
 
@@ -34,6 +38,19 @@ pub fn text() -> Option<String> {
     imp::text()
 }
 
+/// The clipboard's image as PNG bytes, None when it holds none. Call on the main
+/// thread on macOS.
+#[cfg(any(windows, target_os = "macos"))]
+pub fn png() -> Option<Vec<u8>> {
+    imp::png()
+}
+
+/// Whether the clipboard holds an image, without reading it. Call on the main
+/// thread on macOS and Linux.
+pub fn has_image() -> bool {
+    imp::has_image()
+}
+
 /// Size of `DROPFILES`: `pFiles`, `pt` (two `LONG`s), `fNC`, `fWide`.
 const HEADER: usize = 20;
 
@@ -134,9 +151,62 @@ pub fn decode(bytes: &[u8]) -> Vec<PathBuf> {
     out
 }
 
+/// `BI_RGB` and `BI_BITFIELDS`: uncompressed pixels, the forms screenshots take.
+#[cfg(any(windows, test))]
+const BI_RGB: u32 = 0;
+#[cfg(any(windows, test))]
+const BI_BITFIELDS: u32 = 3;
+
+/// A packed DIB (`BITMAPINFOHEADER` or a later header, then the pixels) as PNG.
+/// Only 24- and 32-bit uncompressed bitmaps, which is what screenshots and
+/// copied images are; None for anything else. A 32-bit bitmap whose alpha is
+/// all zero (most writers leave it unset) is opaque.
+#[cfg(any(windows, test))]
+fn dib_to_png(dib: &[u8]) -> Option<Vec<u8>> {
+    let u32_at = |at: usize| dib.get(at..at + 4).map(|b| u32::from_le_bytes([b[0], b[1], b[2], b[3]]));
+    let header = u32_at(0)? as usize;
+    let width = u32_at(4)? as i32;
+    let height = u32_at(8)? as i32;
+    let bits = u16::from_le_bytes([*dib.get(14)?, *dib.get(15)?]);
+    let compression = u32_at(16)?;
+    if header < 40 || width <= 0 || height == 0 || !matches!(bits, 24 | 32) {
+        return None;
+    }
+    if compression != BI_RGB && !(compression == BI_BITFIELDS && bits == 32) {
+        return None;
+    }
+    // A `BITMAPINFOHEADER` keeps the three bitfield masks after it; later
+    // headers hold them inside. Masks other than BGRA's are not supported.
+    let masks = if compression == BI_BITFIELDS && header == 40 { 12 } else { 0 };
+    let colors = u32_at(32)? as usize;
+    let (width, rows) = (width as usize, height.unsigned_abs() as usize);
+    let stride = (width * bits as usize).div_ceil(32) * 4;
+    let start = header + masks + colors * 4;
+    let pixels = dib.get(start..start.checked_add(stride.checked_mul(rows)?)?)?;
+    let step = bits as usize / 8;
+    let mut rgba = Vec::with_capacity(width * rows * 4);
+    for row in 0..rows {
+        // A positive height stores the bottom row first.
+        let source = if height > 0 { rows - 1 - row } else { row };
+        let line = &pixels[source * stride..source * stride + width * step];
+        for px in line.chunks_exact(step) {
+            rgba.extend_from_slice(&[px[2], px[1], px[0], if step == 4 { px[3] } else { 255 }]);
+        }
+    }
+    if step == 4 && rgba.as_chunks::<4>().0.iter().all(|px| px[3] == 0) {
+        rgba.as_chunks_mut::<4>().0.iter_mut().for_each(|px| px[3] = 255);
+    }
+    let mut out = Vec::new();
+    let mut encoder = png::Encoder::new(&mut out, width as u32, rows as u32);
+    encoder.set_color(png::ColorType::Rgba);
+    encoder.set_depth(png::BitDepth::Eight);
+    encoder.write_header().ok()?.write_image_data(&rgba).ok()?;
+    Some(out)
+}
+
 #[cfg(windows)]
 mod imp {
-    use super::{HEADER, decode, encode, names_text};
+    use super::{HEADER, decode, dib_to_png, encode, names_text};
     use std::ffi::c_void;
     use std::path::PathBuf;
     use std::ptr;
@@ -164,6 +234,59 @@ mod imp {
         fn GetClipboardData(format: u32) -> Handle;
         fn SetClipboardData(format: u32, memory: Handle) -> Handle;
         fn IsClipboardFormatAvailable(format: u32) -> i32;
+        fn RegisterClipboardFormatW(name: *const u16) -> u32;
+    }
+
+    /// `CF_DIB`: Windows synthesizes it from `CF_BITMAP` and `CF_DIBV5`, so every
+    /// bitmap on the clipboard reads as one.
+    const CF_DIB: u32 = 8;
+
+    /// The `PNG` format browsers and the Snipping Tool add beside the bitmap; it
+    /// keeps transparency, so it is read first.
+    fn png_format() -> u32 {
+        let name: Vec<u16> = "PNG\0".encode_utf16().collect();
+        unsafe { RegisterClipboardFormatW(name.as_ptr()) }
+    }
+
+    pub fn has_image() -> bool {
+        let png = png_format();
+        (png != 0 && unsafe { IsClipboardFormatAvailable(png) } != 0)
+            || unsafe { IsClipboardFormatAvailable(CF_DIB) } != 0
+    }
+
+    /// A copy of the clipboard's `format` block. Call with the clipboard open.
+    fn read_block(format: u32) -> Option<Vec<u8>> {
+        // SAFETY: the clipboard keeps the block alive while it is open, and
+        // `GlobalSize` bounds the bytes read from it.
+        unsafe {
+            let memory = GetClipboardData(format);
+            if memory.is_null() {
+                return None;
+            }
+            let data = GlobalLock(memory);
+            if data.is_null() {
+                return None;
+            }
+            let bytes = std::slice::from_raw_parts(data as *const u8, GlobalSize(memory)).to_vec();
+            GlobalUnlock(memory);
+            Some(bytes)
+        }
+    }
+
+    pub fn png() -> Option<Vec<u8>> {
+        if !open() {
+            return None;
+        }
+        let png = png_format();
+        let image = if png != 0 && unsafe { IsClipboardFormatAvailable(png) } != 0 {
+            read_block(png)
+        } else if unsafe { IsClipboardFormatAvailable(CF_DIB) } != 0 {
+            read_block(CF_DIB).and_then(|dib| dib_to_png(&dib))
+        } else {
+            None
+        };
+        unsafe { CloseClipboard() };
+        image
     }
 
     #[link(name = "kernel32")]
@@ -327,8 +450,8 @@ mod imp {
     use objc2::runtime::{AnyClass, AnyObject, ProtocolObject};
     use objc2::{ClassType, MainThreadMarker};
     use objc2_app_kit::{
-        NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardTypeString, NSPasteboardURLReadingFileURLsOnlyKey,
-        NSPasteboardWriting,
+        NSBitmapImageFileType, NSBitmapImageRep, NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardTypePNG,
+        NSPasteboardTypeString, NSPasteboardTypeTIFF, NSPasteboardURLReadingFileURLsOnlyKey, NSPasteboardWriting,
     };
     use objc2_foundation::{NSArray, NSDictionary, NSNumber, NSString, NSURL};
     use std::path::PathBuf;
@@ -380,6 +503,33 @@ mod imp {
         })
     }
 
+    pub fn has_image() -> bool {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
+        autoreleasepool(|_| {
+            // SAFETY: the types are AppKit constants, valid for the process' lifetime.
+            let types = NSArray::from_slice(&[unsafe { NSPasteboardTypePNG }, unsafe { NSPasteboardTypeTIFF }]);
+            NSPasteboard::generalPasteboard().availableTypeFromArray(&types).is_some()
+        })
+    }
+
+    /// PNG as copied, else TIFF (what macOS screenshots and most apps write) converted.
+    pub fn png() -> Option<Vec<u8>> {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
+        autoreleasepool(|_| {
+            let board = NSPasteboard::generalPasteboard();
+            // SAFETY: the types are AppKit constants, valid for the process' lifetime.
+            if let Some(png) = board.dataForType(unsafe { NSPasteboardTypePNG }) {
+                return Some(png.to_vec());
+            }
+            let tiff = board.dataForType(unsafe { NSPasteboardTypeTIFF })?;
+            let image = NSBitmapImageRep::imageRepWithData(&tiff)?;
+            // SAFETY: an empty property dictionary is valid for every file type.
+            let png =
+                unsafe { image.representationUsingType_properties(NSBitmapImageFileType::PNG, &NSDictionary::new()) }?;
+            Some(png.to_vec())
+        })
+    }
+
     pub fn text() -> Option<String> {
         debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
         autoreleasepool(|_| {
@@ -448,6 +598,17 @@ mod imp {
         false
     }
 
+    pub fn has_image() -> bool {
+        #[cfg(target_os = "linux")]
+        {
+            gtk::Clipboard::get(&gtk::gdk::SELECTION_CLIPBOARD).wait_is_image_available()
+        }
+        #[cfg(not(target_os = "linux"))]
+        {
+            false
+        }
+    }
+
     pub fn files() -> std::io::Result<Vec<PathBuf>> {
         Ok(Vec::new())
     }
@@ -521,4 +682,62 @@ mod tests {
         bytes.extend_from_slice(b"C:\\a\\b.txt\0C:\\c\0\0");
         assert_eq!(decode(&bytes), paths(&["C:\\a\\b.txt", "C:\\c"]));
     }
+
+    /// A `BITMAPINFOHEADER` DIB of `width` × `height` (positive: bottom-up).
+    fn dib(width: i32, height: i32, bits: u16, compression: u32, rows: &[&[u8]]) -> Vec<u8> {
+        let mut out = Vec::new();
+        out.extend_from_slice(&40u32.to_le_bytes());
+        out.extend_from_slice(&width.to_le_bytes());
+        out.extend_from_slice(&height.to_le_bytes());
+        out.extend_from_slice(&1u16.to_le_bytes());
+        out.extend_from_slice(&bits.to_le_bytes());
+        out.extend_from_slice(&compression.to_le_bytes());
+        out.extend_from_slice(&[0u8; 20]);
+        if compression == super::BI_BITFIELDS {
+            for mask in [0x00ff_0000u32, 0x0000_ff00, 0x0000_00ff] {
+                out.extend_from_slice(&mask.to_le_bytes());
+            }
+        }
+        for row in rows {
+            out.extend_from_slice(row);
+        }
+        out
+    }
+
+    fn decode_png(png: &[u8]) -> (u32, u32, Vec<u8>) {
+        let mut reader = png::Decoder::new(std::io::Cursor::new(png)).read_info().unwrap();
+        let mut buf = vec![0; reader.output_buffer_size().unwrap()];
+        let info = reader.next_frame(&mut buf).unwrap();
+        buf.truncate(info.buffer_size());
+        (info.width, info.height, buf)
+    }
+
+    #[test]
+    fn a_bottom_up_24_bit_bitmap_becomes_an_upright_opaque_png() {
+        // Rows are padded to 4 bytes; the first stored row is the bottom one.
+        let bottom: &[u8] = &[255, 0, 0, 0, 255, 0, 0, 0];
+        let top: &[u8] = &[0, 0, 255, 255, 255, 255, 0, 0];
+        let png = super::dib_to_png(&dib(2, 2, 24, super::BI_RGB, &[bottom, top])).unwrap();
+        let (w, h, rgba) = decode_png(&png);
+        assert_eq!((w, h), (2, 2));
+        assert_eq!(rgba, [255, 0, 0, 255, 255, 255, 255, 255, 0, 0, 255, 255, 0, 255, 0, 255]);
+    }
+
+    #[test]
+    fn a_32_bit_bitmap_keeps_its_alpha_unless_none_was_written() {
+        let row: &[u8] = &[10, 20, 30, 0, 40, 50, 60, 0];
+        let (_, _, rgba) = decode_png(&super::dib_to_png(&dib(2, -1, 32, super::BI_BITFIELDS, &[row])).unwrap());
+        assert_eq!(rgba, [30, 20, 10, 255, 60, 50, 40, 255]);
+        let row: &[u8] = &[10, 20, 30, 128, 40, 50, 60, 0];
+        let (_, _, rgba) = decode_png(&super::dib_to_png(&dib(2, -1, 32, super::BI_RGB, &[row])).unwrap());
+        assert_eq!(rgba, [30, 20, 10, 128, 60, 50, 40, 0]);
+    }
+
+    #[test]
+    fn unsupported_or_truncated_bitmaps_are_not_images() {
+        let row: &[u8] = &[1, 2, 3, 4];
+        assert!(super::dib_to_png(&dib(4, 1, 8, super::BI_RGB, &[row])).is_none());
+        assert!(super::dib_to_png(&dib(2, 2, 24, super::BI_RGB, &[row])).is_none());
+        assert!(super::dib_to_png(&[0; 10]).is_none());
+    }
 }

crates/ide-core/src/process.rs

@@ -141,6 +141,30 @@ pub fn process_tree(pid: i32) -> Vec<i32> {
     tree
 }
 
+/// Every process `pid` started, directly or not, parents before their children.
+pub fn descendants(pid: u32) -> Vec<u32> {
+    #[cfg(unix)]
+    {
+        let Ok(root) = i32::try_from(pid) else { return Vec::new() };
+        process_tree(root).into_iter().skip(1).filter_map(|p| u32::try_from(p).ok()).collect()
+    }
+    #[cfg(windows)]
+    {
+        use std::os::windows::io::AsRawHandle;
+        windows_tree::descendants(pid)
+            .iter()
+            // SAFETY: a live process handle opened with query access.
+            .map(|h| unsafe { windows_sys::Win32::System::Threading::GetProcessId(h.as_raw_handle()) })
+            .filter(|&p| p != 0)
+            .collect()
+    }
+    #[cfg(not(any(unix, windows)))]
+    {
+        let _ = pid;
+        Vec::new()
+    }
+}
+
 /// [`kill_tree`] that first asks the group to exit: `SIGTERM`, then `grace`, then `SIGKILL`.
 /// Git removes its `index.lock` on `SIGTERM`, where `SIGKILL` leaves it behind and the next
 /// git command fails. Windows has no such signal to send from outside the child's console,

crates/ide-core/src/settings.rs

@@ -86,6 +86,8 @@ pub struct AgentSettings {
     pub fold_turns: bool,
     /// Streaming text is revealed at a steady pace rather than chunk by chunk.
     pub smooth_text: bool,
+    /// Conversations and the composer expand to the full width of the pane instead of staying in a centred column.
+    pub fit_window_width: bool,
     #[serde(deserialize_with = "or_default")]
     #[specta(type = ThinkingDisplay)]
     pub thinking: ThinkingDisplay,
@@ -127,6 +129,7 @@ impl Default for AgentSettings {
             show_cost: false,
             fold_turns: true,
             smooth_text: true,
+            fit_window_width: false,
             thinking: ThinkingDisplay::Auto,
             tool_calls: ToolCallDisplay::Grouped,
             expand_tool_output: false,
@@ -1715,11 +1718,15 @@ mod tests {
         let old: Settings = serde_json::from_str(r#"{"agents":{"showCost":true}}"#).unwrap();
         assert!(old.agents.show_cost);
         assert!(old.agents.show_context_usage && old.agents.show_work_time && old.agents.show_usage_limits);
+        assert!(!old.agents.fit_window_width);
         assert!(!Settings::default().agents.show_cost);
+        assert!(!Settings::default().agents.fit_window_width);
         let mut settings = Settings::default();
         settings.agents.show_usage_limits = false;
+        settings.agents.fit_window_width = true;
         let json = serde_json::to_value(&settings).unwrap();
         assert_eq!(json["agents"]["showUsageLimits"], false);
+        assert_eq!(json["agents"]["fitWindowWidth"], true);
         let restored: Settings = serde_json::from_value(json).unwrap();
         assert_eq!(restored.agents, settings.agents);
     }

crates/ide-dap/src/attach.rs

@@ -405,6 +405,24 @@ pub fn attachable_processes() -> IdeResult<Vec<AttachableProcess>> {
     Ok(out)
 }
 
+/// The Attach to Process candidates among the processes `root` started, parents first.
+/// Blocking, like [`attachable_processes`].
+pub fn attachable_descendants(root: u32) -> IdeResult<Vec<AttachableProcess>> {
+    let order = ide_core::process::descendants(root);
+    if order.is_empty() {
+        return Ok(Vec::new());
+    }
+    let cwd = std::env::temp_dir();
+    let native = if adapter::resolve_binary("codelldb", &cwd).is_some() { "codelldb" } else { "lldb-dap" };
+    let mut out: Vec<AttachableProcess> = list_processes()?
+        .iter()
+        .filter(|p| order.contains(&p.pid))
+        .filter_map(|p| classify(p, is_dotnet, is_go_binary, native))
+        .collect();
+    out.sort_by_key(|p| order.iter().position(|&pid| pid == p.pid));
+    Ok(out)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -418,6 +436,28 @@ mod tests {
             .map(|p| (p.kind, p.port))
     }
 
+    #[cfg(unix)]
+    #[test]
+    fn a_runs_candidates_are_the_processes_it_started() {
+        let mut child = std::process::Command::new("sh").args(["-c", "sleep 30; true"]).spawn().unwrap();
+        let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
+        let found = loop {
+            let found = attachable_descendants(child.id()).unwrap();
+            if !found.is_empty() || std::time::Instant::now() > deadline {
+                break found;
+            }
+            std::thread::sleep(std::time::Duration::from_millis(50));
+        };
+        for p in &found {
+            let _ = std::process::Command::new("kill").arg(p.pid.to_string()).status();
+        }
+        child.kill().unwrap();
+        child.wait().unwrap();
+        assert!(found.iter().all(|p| p.pid != child.id()), "{found:?}");
+        assert!(found.iter().any(|p| p.name == "sleep" && p.kind == AttachKind::Native), "{found:?}");
+        assert!(attachable_descendants(u32::MAX - 1).unwrap().is_empty());
+    }
+
     #[test]
     fn parses_jdwp_agents() {
         let a = "java -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005 -jar app.jar";

crates/ide-extension/src/manifest.rs

@@ -34,7 +34,7 @@ use std::path::{Component, Path, PathBuf};
 
 pub const MANIFEST_FILE: &str = "plugin.toml";
 /// The plugin API (engine) version this host implements.
-pub const ENGINE_VERSION: &str = "1.8.0";
+pub const ENGINE_VERSION: &str = "1.9.0";
 /// The 0.1 API, still accepted for contribution-only packages and 0.1 components.
 pub const LEGACY_API: &str = "0.1";
 /// Marketplace categories, in the order they are shown.

crates/ide-host/src/mcp/editors.rs

@@ -1,6 +1,10 @@
+use super::page::{OFFSET, Page};
 use super::tool::{Call, Output, Param, ParamType, Tool};
 use ide_core::{Diagnostic, IdeResult, Severity};
-use serde_json::{Value, json};
+use serde_json::{Map, Value, json};
+
+/// Problems `get_project_problems` lists by default.
+const PROBLEMS_LIMIT: usize = 100;
 
 pub fn tools() -> Vec<Tool> {
     vec![
@@ -37,7 +41,10 @@ Lines and UTF-16 columns are 1-based.",
 and inspections after profile filtering. This reflects what the Problems view shows, rather than a fresh analysis.
 Lines and UTF-16 columns are 1-based.",
             project_problems,
-        ),
+        )
+        .param(Param::optional("errorsOnly", ParamType::Boolean, "Only errors (default) or warnings too"))
+        .param(Param::optional("limit", ParamType::Integer, "Problems to return at most (default 100)"))
+        .param(Param::optional("offset", ParamType::Integer, OFFSET)),
     ]
 }
 
@@ -90,9 +97,25 @@ async fn file_problems(call: Call) -> IdeResult<Output> {
 }
 
 async fn project_problems(call: Call) -> IdeResult<Output> {
+    let page = Page::of(&call, PROBLEMS_LIMIT)?;
+    let errors_only = call.flag("errorsOnly", true)?;
     let files = call.host.mcp_reports.problems(&call.host.mcp_windows(call.root()));
-    let files: Vec<_> = files.into_iter().map(|f| json!({
-        "filePath":call.display(&f.path.0), "problems": f.items.into_iter().map(|d| problem(d, "")).collect::<Vec<_>>()
-    })).collect();
-    Output::json(json!({"files":files}))
+    let problems: Vec<(String, Value)> = files
+        .into_iter()
+        .flat_map(|f| {
+            let path = call.display(&f.path.0);
+            let wanted = f.items.into_iter().filter(|d| !errors_only || d.severity == Severity::Error);
+            wanted.map(move |d| (path.clone(), problem(d, "")))
+        })
+        .collect();
+    let mut out = Map::new();
+    let mut files: Vec<Value> = Vec::new();
+    for (path, problem) in page.take(problems, &mut out) {
+        match files.last_mut() {
+            Some(file) if file["filePath"] == path.as_str() => file["problems"].as_array_mut().unwrap().push(problem),
+            _ => files.push(json!({ "filePath": path, "problems": [problem] })),
+        }
+    }
+    out.insert("files".into(), files.into());
+    Output::json(Value::Object(out))
 }

crates/ide-host/src/mcp/files.rs

@@ -2,6 +2,7 @@
 // the list_directory_tree part of FileToolset.kt, src/com/intellij/mcpserver/util/fs.util.kt), Apache-2.0.
 //! Reading files and listing directories.
 
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use crate::mcp::util::{
     self, RELATIVE_PATH_IN_PROJECT_DESCRIPTION, TIMED_OUT_DESCRIPTION, TIMEOUT_MILLISECONDS_DESCRIPTION,
@@ -17,6 +18,8 @@ const MAX_READ_LIMIT: i64 = 5000;
 /// Longer lines are cut (minified files would flood the context), in UTF-16 units.
 const MAX_LINE_LENGTH: usize = 2000;
 const DEFAULT_TREE_DEPTH: i64 = 5;
+/// Entries `list_directory_tree` lists by default.
+const TREE_LIMIT: usize = 100;
 
 pub fn tools() -> Vec<Tool> {
     vec![read_file(), list_directory_tree()]
@@ -149,6 +152,12 @@ struct DirectoryTreeInfo {
     errors: Vec<String>,
     #[serde(skip_serializing_if = "std::ops::Not::not")]
     listing_timed_out: bool,
+    /// Entries under the directory within `maxDepth`.
+    total: usize,
+    #[serde(skip_serializing_if = "std::ops::Not::not")]
+    more: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    next_offset: Option<usize>,
 }
 
 fn list_directory_tree() -> Tool {
@@ -156,10 +165,12 @@ fn list_directory_tree() -> Tool {
         "list_directory_tree",
         "Provides a tree representation of the specified directory in the pseudo graphic format like `tree` utility does.
 Use this tool to explore the contents of a directory or the whole project.
-You MUST prefer this tool over listing directories via command line utilities like `ls` or `dir`.",
+You MUST prefer this tool over listing directories via command line utilities like `ls` or `dir`.
+A page that starts inside a directory repeats the lines of the directories above it.",
         |call| async move {
             let directory = call.str("directoryPath")?;
             let max_depth = call.opt_i64("maxDepth")?.unwrap_or(DEFAULT_TREE_DEPTH);
+            let page = Page::of(&call, TREE_LIMIT)?;
             let timeout = call.opt_i64("timeout")?.unwrap_or(util::MEDIUM_TIMEOUT.as_millis() as i64);
             let dir = call.resolve_readable(&directory).await?;
             if !dir.exists() {
@@ -170,8 +181,16 @@ You MUST prefer this tool over listing directories via command line utilities li
             }
             let deadline = Instant::now() + Duration::from_millis(timeout.max(0) as u64);
             let cancel = call.cancel.clone();
-            let mut tree =
-                TreeRender { out: String::new(), errors: Vec::new(), timed_out: false, deadline, cancel: cancel.clone() };
+            let mut tree = TreeRender {
+                out: String::new(),
+                errors: Vec::new(),
+                timed_out: false,
+                deadline,
+                cancel: cancel.clone(),
+                page,
+                seen: 0,
+                above: Vec::new(),
+            };
             let tree = call
                 .host()
                 .blocking(move || {
@@ -187,11 +206,16 @@ You MUST prefer this tool over listing directories via command line utilities li
                 tree: tree.out,
                 errors: tree.errors,
                 listing_timed_out: tree.timed_out,
+                total: tree.seen,
+                more: tree.seen > page.end(),
+                next_offset: (tree.seen > page.end()).then_some(page.end()),
             })
         },
     )
     .param(Param::required("directoryPath", ParamType::String, RELATIVE_PATH_IN_PROJECT_DESCRIPTION))
     .param(Param::optional("maxDepth", ParamType::Integer, "Maximum recursion depth"))
+    .param(Param::optional("limit", ParamType::Integer, "Entries to return at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("timeout", ParamType::Integer, TIMEOUT_MILLISECONDS_DESCRIPTION))
     .output(json!({
         "type": "object",
@@ -200,19 +224,28 @@ You MUST prefer this tool over listing directories via command line utilities li
             "tree": { "type": "string" },
             "errors": { "type": "array", "items": { "type": "string" } },
             "listingTimedOut": { "type": "boolean", "description": TIMED_OUT_DESCRIPTION },
+            "total": { "type": "integer" },
+            "more": { "type": "boolean" },
+            "nextOffset": { "type": "integer" },
         },
-        "required": ["traversedDirectory", "tree", "errors"],
+        "required": ["traversedDirectory", "tree", "errors", "total"],
     }))
 }
 
 /// The `tree`-like listing: the directory's absolute path, then every entry (hidden and
-/// ignored ones too) by lower-cased name, directories marked with `/`.
+/// ignored ones too) by lower-cased name, directories marked with `/`; entries outside the
+/// page are counted, not listed.
 struct TreeRender {
     out: String,
     errors: Vec<String>,
     timed_out: bool,
     deadline: Instant,
     cancel: CancellationToken,
+    page: Page,
+    /// Entries met so far.
+    seen: usize,
+    /// The lines of the directories above the entry, and whether this page shows them yet.
+    above: Vec<(String, bool)>,
 }
 
 impl TreeRender {
@@ -235,7 +268,13 @@ impl TreeRender {
             path.file_name().unwrap_or_default().to_string_lossy().into_owned()
         };
         let is_dir = path.is_dir() && !path.is_symlink();
-        self.out.push_str(&format!("{indent}{prefix}{name}{}\n", if is_dir { "/" } else { "" }));
+        let line = format!("{indent}{prefix}{name}{}\n", if is_dir { "/" } else { "" });
+        let shown = if is_root {
+            self.out.push_str(&line);
+            true
+        } else {
+            self.entry(&line)
+        };
         if !is_dir {
             return;
         }
@@ -250,9 +289,32 @@ impl TreeRender {
         children.sort_by_cached_key(|p| (key(p).to_lowercase(), key(p)));
         let child_indent = format!("{indent}{}", if is_last { "    " } else { "│   " });
         let n = children.len();
+        if !is_root {
+            self.above.push((line, shown));
+        }
         for (i, child) in children.iter().enumerate() {
             self.render(child, &child_indent, i + 1 == n, max_depth - 1, false);
         }
+        if !is_root {
+            self.above.pop();
+        }
+    }
+
+    /// Counts an entry and lists it when on the page, after the directories above it.
+    fn entry(&mut self, line: &str) -> bool {
+        let n = self.seen;
+        self.seen += 1;
+        if n < self.page.offset || n >= self.page.end() {
+            return false;
+        }
+        for (above, shown) in &mut self.above {
+            if !*shown {
+                self.out.push_str(above);
+                *shown = true;
+            }
+        }
+        self.out.push_str(line);
+        true
     }
 }
 
@@ -302,4 +364,36 @@ mod tests {
         let short = format!("{}😀", "x".repeat(1998));
         assert_eq!(format_line(&short), short);
     }
+
+    #[test]
+    fn a_tree_page_repeats_the_directories_above_it() {
+        let tmp = tempfile::tempdir().unwrap();
+        for file in ["a/x.txt", "a/y.txt", "b.txt"] {
+            let path = tmp.path().join(file);
+            std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+            std::fs::write(path, "").unwrap();
+        }
+        let render = |offset, limit| {
+            let mut tree = TreeRender {
+                out: String::new(),
+                errors: Vec::new(),
+                timed_out: false,
+                deadline: Instant::now() + Duration::from_secs(10),
+                cancel: CancellationToken::new(),
+                page: Page { offset, limit },
+                seen: 0,
+                above: Vec::new(),
+            };
+            tree.render(tmp.path(), "", true, 5, true);
+            let root = format!("{}/\n", tmp.path().display());
+            (tree.out.strip_prefix(&root).unwrap().to_owned(), tree.seen)
+        };
+        assert_eq!(render(0, 2), ("    ├── a/\n    │   ├── x.txt\n".to_owned(), 4));
+        assert_eq!(
+            render(2, 2).0,
+            "    ├── a/\n    │   └── y.txt\n    └── b.txt\n",
+            "the page in `a/` repeats its line"
+        );
+        assert_eq!(render(0, 100).0, "    ├── a/\n    │   ├── x.txt\n    │   └── y.txt\n    └── b.txt\n");
+    }
 }

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

@@ -7,6 +7,7 @@ pub(crate) mod run;
 mod vcs;
 pub use requests::Requests;
 mod files;
+mod page;
 mod reports;
 mod search;
 mod symbols;

crates/ide-host/src/mcp/page.rs

@@ -0,0 +1,71 @@
+//! `limit` and `offset` of the tools that list things: a few items by default, the rest page by page.
+
+use super::tool::Call;
+use ide_core::{IdeError, IdeResult};
+use serde_json::{Map, Value};
+
+/// The most items one call returns.
+pub const MAX_LIMIT: usize = 1000;
+pub const OFFSET: &str = "Items to skip: `nextOffset` of the previous page";
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct Page {
+    pub offset: usize,
+    pub limit: usize,
+}
+
+impl Page {
+    /// The `limit` (`default` when absent, at most [`MAX_LIMIT`]) and `offset` (0) arguments.
+    pub fn of(call: &Call, default: usize) -> IdeResult<Self> {
+        let limit = match call.opt_i64("limit")? {
+            None => default,
+            Some(n) if n <= 0 => return Err(IdeError::invalid("limit must be > 0")),
+            Some(n) => (n as usize).min(MAX_LIMIT),
+        };
+        let offset = match call.opt_i64("offset")? {
+            None => 0,
+            Some(n) if n < 0 => return Err(IdeError::invalid("offset must be >= 0")),
+            Some(n) => n as usize,
+        };
+        Ok(Self { offset, limit })
+    }
+
+    /// Where the page ends: the items to find for it.
+    pub fn end(&self) -> usize {
+        self.offset.saturating_add(self.limit)
+    }
+
+    /// This page of all the `items`; `out` gets their `total`, and `more` and `nextOffset` when some follow.
+    pub fn take<T>(&self, items: Vec<T>, out: &mut Map<String, Value>) -> Vec<T> {
+        let total = items.len();
+        out.insert("total".into(), total.into());
+        self.mark(total > self.end(), out);
+        items.into_iter().skip(self.offset).take(self.limit).collect()
+    }
+
+    /// `more` and `nextOffset` when items follow the page.
+    pub fn mark(&self, more: bool, out: &mut Map<String, Value>) {
+        if more {
+            out.insert("more".into(), true.into());
+            out.insert("nextOffset".into(), self.end().into());
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn pages_say_what_follows() {
+        let page = |offset, limit| Page { offset, limit };
+        let mut out = Map::new();
+        assert_eq!(page(0, 2).take(vec![1, 2, 3, 4, 5], &mut out), [1, 2]);
+        assert_eq!(Value::Object(out), serde_json::json!({ "total": 5, "more": true, "nextOffset": 2 }));
+        let mut out = Map::new();
+        assert_eq!(page(4, 2).take(vec![1, 2, 3, 4, 5], &mut out), [5]);
+        assert_eq!(Value::Object(out), serde_json::json!({ "total": 5 }), "the last page");
+        let mut out = Map::new();
+        assert!(page(9, 2).take(vec![1], &mut out).is_empty());
+    }
+}

crates/ide-host/src/mcp/run/agent_tools.rs

@@ -3,6 +3,7 @@
 
 use super::agent::{AgentRun, INTERVENTION_ADVICE, TruncateMode, clean_output, tab_name, truncate_lines};
 use super::output::RUN_PREVIEW_MAX_LENGTH;
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::run::timeout;
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use ide_core::{IdeError, IdeResult};
@@ -35,6 +36,14 @@ and `nextOffset` are positions in the tab's raw output log; pass `nextOffset` as
 const MAX_LINES: &str = "Lines of output to return at most (default 2000)";
 const TRUNCATE_MODE: &str = "Which lines to leave out beyond maxLinesCount: START (default, keeps the end), END \
 (keeps the start), MIDDLE (keeps both ends) or NONE";
+/// `list_runs`: tabs returned by default, and characters of each command, enough to tell them apart.
+const LIST_LIMIT: usize = 10;
+const LIST_COMMAND_CHARS: usize = 80;
+const LIST_STATES: [(&str, &[&str]); 3] = [
+    ("running", &["starting", "running", "stopping"]),
+    ("idle", &["succeeded", "failed", "crashed", "stoppedByAgent", "stoppedByUser", "startFailed"]),
+    ("error", &["failed", "crashed", "startFailed"]),
+];
 
 fn find(call: &Call) -> IdeResult<Arc<AgentRun>> {
     let name = tab_name(&call.str("name")?)?;
@@ -283,13 +292,64 @@ for input) and `tabClosedAt` when the user closed the tab.{INTERVENTIONS}"
 pub fn list_runs() -> Tool {
     Tool::new(
         "list_runs",
-        "Lists the agent tabs of the project (those started by `run_command`) with their status.",
+        "Lists the agent tabs of the project (those started by `run_command`), newest first: name, state, the \
+start of the command, exit code and times. `get_run_status` gives a tab's whole status.",
         |call| async move {
-            let runs: Vec<Value> =
-                call.host().mcp_agent_runs.list(call.root()).iter().map(|r| Value::Object(r.status())).collect();
-            Output::json(serde_json::json!({ "runs": runs }))
+            let page = Page::of(&call, LIST_LIMIT)?;
+            let wanted = call.opt_str("state")?.filter(|s| s != "all");
+            let states = match wanted.as_deref() {
+                None => None,
+                Some(s) => Some(match LIST_STATES.iter().find(|(group, _)| *group == s) {
+                    Some((_, states)) => states.to_vec(),
+                    None if LIST_STATES[1].1.contains(&s) || LIST_STATES[0].1.contains(&s) => vec![s],
+                    None => {
+                        return Err(IdeError::invalid(format!(
+                            "unknown state `{s}`: all, running, idle, error, or one of the states of get_run_status"
+                        )));
+                    }
+                }),
+            };
+            let runs: Vec<Value> = call
+                .host()
+                .mcp_agent_runs
+                .list(call.root())
+                .iter()
+                .rev()
+                .map(|r| r.status())
+                .filter(|s| {
+                    states.as_ref().is_none_or(|states| s["state"].as_str().is_some_and(|v| states.contains(&v)))
+                })
+                .map(|s| Value::Object(brief(s)))
+                .collect();
+            let mut out = Map::new();
+            let runs = page.take(runs, &mut out);
+            out.insert("runs".into(), runs.into());
+            Output::json(Value::Object(out))
         },
     )
+    .param(Param::optional(
+        "state",
+        ParamType::String,
+        "all (default), running, idle (not running), error (failed, crashed, startFailed), or one state",
+    ))
+    .param(Param::optional("limit", ParamType::Integer, "Tabs to return at most (default 10)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
+}
+
+/// A tab in `list_runs`: what tells it apart and how it went, the command cut short.
+fn brief(mut status: Map<String, Value>) -> Map<String, Value> {
+    let mut out = Map::new();
+    for key in ["name", "state", "command", "exitCode", "crash", "error", "startedAt", "endedAt", "tabClosedAt"] {
+        if let Some(v) = status.remove(key) {
+            out.insert(key.into(), v);
+        }
+    }
+    if let Some(Value::String(command)) = out.get_mut("command")
+        && command.chars().count() > LIST_COMMAND_CHARS
+    {
+        *command = format!("{}…", command.chars().take(LIST_COMMAND_CHARS).collect::<String>());
+    }
+    out
 }
 
 /// What a key does to a command on pipes.
@@ -407,6 +467,22 @@ pub fn tools() -> Vec<Tool> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn listed_tabs_are_brief_and_their_commands_cut_short() {
+        let status = serde_json::json!({
+            "name": "_agent_build", "state": "failed", "command": "x".repeat(100), "exitCode": 1,
+            "workingDirectory": "", "outputLength": 9, "startedBy": "agent",
+        });
+        let Value::Object(status) = status else { unreachable!() };
+        let brief = Value::Object(brief(status));
+        assert_eq!(brief["command"].as_str().unwrap(), format!("{}…", "x".repeat(LIST_COMMAND_CHARS)));
+        assert_eq!(
+            (&brief["name"], &brief["state"], &brief["exitCode"]),
+            (&"_agent_build".into(), &"failed".into(), &1.into())
+        );
+        assert!(brief.get("outputLength").is_none() && brief.get("workingDirectory").is_none());
+    }
+
     #[test]
     fn keys_are_what_pipes_can_take() {
         assert_eq!(key(" enter ").unwrap(), Key::Text("\n"));

crates/ide-host/src/mcp/run/configs.rs

@@ -7,6 +7,7 @@ use super::output::OutputCollector;
 use super::process::{quote, split_words};
 use super::targets;
 use crate::Project;
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::run::timeout;
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use ide_build::compile::BuildKind;
@@ -19,6 +20,8 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 const DEFAULT_TIMEOUT_MS: usize = 10_000;
+/// Configurations `get_run_configurations` lists by default.
+const CONFIGURATIONS_LIMIT: usize = 100;
 /// Output of a failed before-launch process kept for the error message.
 const MAX_PROCESS_OUTPUT_LENGTH: usize = 20_000;
 /// A before-launch build gets this long.
@@ -50,7 +53,8 @@ fn describe_config(call: &Call, c: &RunConfig) -> Value {
         if let Some(cwd) = c.cwd.as_deref() {
             v["workingDirectory"] = call.display(&call.root().join(cwd)).into();
         }
-        if !c.env.is_empty() {
+        // A detected configuration's environment is the IDE's own (its tools on `PATH`).
+        if !c.env.is_empty() && !c.detected {
             v["environment"] = json!(c.env);
         }
     }
@@ -133,8 +137,23 @@ the whole command. Run points are found in Rust, JavaScript/TypeScript, Python a
                 .await?;
                 return Output::json(json!({ "filePath": file, "runPoints": points }));
             }
-            let list: Vec<Value> = configs.iter().map(|c| describe_config(&call, c)).collect();
-            Output::json(json!({ "configurations": list }))
+            let page = Page::of(&call, CONFIGURATIONS_LIMIT)?;
+            let query = call.opt_str("query")?.map(|q| q.to_lowercase());
+            let list: Vec<Value> = configs
+                .iter()
+                .filter(|c| {
+                    query.as_ref().is_none_or(|q| {
+                        [c.name.as_str(), c.kind.as_str(), command_line(c).as_str()]
+                            .iter()
+                            .any(|s| s.to_lowercase().contains(q.as_str()))
+                    })
+                })
+                .map(|c| describe_config(&call, c))
+                .collect();
+            let mut out = Map::new();
+            let list = page.take(list, &mut out);
+            out.insert("configurations".into(), list.into());
+            Output::json(Value::Object(out))
         },
     )
     .write()
@@ -144,6 +163,9 @@ the whole command. Run points are found in Rust, JavaScript/TypeScript, Python a
         "Optional file path relative to the project root. When provided, returns run points (executable entry points) \
 in the file instead of project-wide run configurations.",
     ))
+    .param(Param::optional("query", ParamType::String, "Only configurations whose name, type or command contains it"))
+    .param(Param::optional("limit", ParamType::Integer, "Configurations to return at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
 }
 
 /// What `execute_run_configuration` runs.

crates/ide-host/src/mcp/search.rs

@@ -5,6 +5,7 @@
 //! Coordinates are 1-based, end exclusive; columns count UTF-16 code units like
 //! the editor (one per character except emoji and other astral characters).
 
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use crate::mcp::util::{INDEXING_PARTIAL_RESULT_REASON, MEDIUM_TIMEOUT};
 use crate::ops::search::SearchEvent;
@@ -21,8 +22,8 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 pub const MAX_RESULTS_UPPER_BOUND: usize = 5000;
-const DEFAULT_LIMIT: i64 = 1000;
-pub const SYMBOL_SEARCH_DEFAULT_LIMIT: i64 = 50;
+const DEFAULT_LIMIT: usize = 100;
+pub const SYMBOL_SEARCH_DEFAULT_LIMIT: usize = 50;
 pub const SEARCH_TIMEOUT_PARTIAL_RESULT_REASON: &str =
     "The search timed out after 10 s. Narrow the query or pass paths.";
 /// Symbols requested from the index per result when `paths` filters them afterwards.
@@ -37,7 +38,8 @@ const LINE_WINDOW: usize = 500;
 
 const PATHS_DESCRIPTION: &str = "Optional list of project-relative glob patterns to filter results. Supports '!' \
 excludes. Trailing '/' expands to '**'. Patterns without '/' are treated as '**/pattern'. Empty strings are ignored.";
-const LIMIT_DESCRIPTION: &str = "Maximum number of results to return";
+const LIMIT_DESCRIPTION: &str = "Results to return at most (default 100)";
+const SYMBOL_LIMIT_DESCRIPTION: &str = "Results to return at most (default 50)";
 const CONTEXT_DESCRIPTION: &str = "Lines around each match to return besides the matched line (`lineText`): \"+N\" the \
 N lines after it (`contextAfter`), \"-N\" the N lines before it (`contextBefore`), \"N\" (or the number N) N lines on \
 each side. At most 50. Default: the matched line only.";
@@ -67,6 +69,7 @@ Examples: [\"src/**\", \"!**/test/**\"], [\"**/*.kt\"], [\"foo/\"].",
     .param(Param::required("q", ParamType::String, "Text to search for"))
     .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
     .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("context", ParamType::String, CONTEXT_DESCRIPTION))
     .output(result_schema())
 }
@@ -88,6 +91,7 @@ Examples: [\"src/**\", \"!**/test/**\"], [\"**/*.kt\"], [\"foo/\"].",
     .param(Param::required("q", ParamType::String, "Regex pattern to search for"))
     .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
     .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("context", ParamType::String, CONTEXT_DESCRIPTION))
     .output(result_schema())
 }
@@ -113,7 +117,8 @@ If you don't find a suitable result, try again with include_external=true to sea
         "Whether to include SDK and library symbols. Disabled by default; if nothing suitable is found, try again \
 with include_external=true.",
     ))
-    .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("limit", ParamType::Integer, SYMBOL_LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("context", ParamType::String, CONTEXT_DESCRIPTION))
     .output(result_schema())
 }
@@ -138,6 +143,7 @@ Paths are optional additional glob filters relative to the project root.",
         "Whether to include excluded/ignored files in results",
     ))
     .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .output(result_schema())
 }
 
@@ -191,6 +197,9 @@ struct SearchResult {
     items: Vec<SearchItem>,
     #[serde(skip_serializing_if = "std::ops::Not::not")]
     more: bool,
+    /// The `offset` of the next page, when `more`.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    next_offset: Option<usize>,
     #[serde(skip_serializing_if = "Option::is_none")]
     partial_result_reason: Option<&'static str>,
 }
@@ -212,16 +221,23 @@ fn result_schema() -> Value {
                 "required": ["filePath"],
             } },
             "more": { "type": "boolean" },
+            "nextOffset": int,
             "partialResultReason": string,
         },
     })
 }
 
-fn limit(call: &Call, default: i64) -> IdeResult<usize> {
-    match call.opt_i64("limit")?.unwrap_or(default) {
-        n if n <= 0 => Err(IdeError::invalid("limit must be > 0")),
-        n => Ok((n as usize).min(MAX_RESULTS_UPPER_BOUND)),
-    }
+/// The page of `call` and the results to find for it: up to its end.
+fn page(call: &Call, default: usize) -> IdeResult<(Page, usize)> {
+    let page = Page::of(call, default)?;
+    Ok((page, page.end().min(MAX_RESULTS_UPPER_BOUND)))
+}
+
+/// Drops the results before the page, and the `nextOffset` when more follow. A search finds
+/// [`MAX_RESULTS_UPPER_BOUND`] results at most, so no page starts past them.
+fn skip<T>(page: Page, items: &mut Vec<T>, more: bool) -> Option<usize> {
+    items.drain(..page.offset.min(items.len()));
+    (more && page.end() < MAX_RESULTS_UPPER_BOUND).then_some(page.end())
 }
 
 fn query(call: &Call, empty: &str) -> IdeResult<String> {
@@ -521,7 +537,7 @@ struct TextHit {
 
 async fn text_search(call: Call, is_regex: bool) -> IdeResult<Output> {
     let pattern = query(&call, if is_regex { "Regex pattern is empty" } else { "Search text is empty" })?;
-    let limit = limit(&call, DEFAULT_LIMIT)?;
+    let (page, limit) = page(&call, DEFAULT_LIMIT)?;
     let around = context(&call)?;
     let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
     // Globs Find in Files cannot take are applied afterwards, so the engine must not
@@ -612,11 +628,12 @@ async fn text_search(call: Call, is_regex: bool) -> IdeResult<Output> {
             ..Default::default()
         })
         .collect();
+    let next_offset = skip(page, &mut items, more);
     let absolute: std::collections::HashMap<&str, &Path> =
         files.iter().map(|(path, file)| (path.as_str(), file.path.0.as_path())).collect();
     fill_lines(&call, &mut items, |item| absolute.get(item.file_path.as_str()).map(|p| p.to_path_buf()), around).await;
     let partial_result_reason = timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON);
-    Output::json(SearchResult { items, more, partial_result_reason })
+    Output::json(SearchResult { items, more, next_offset, partial_result_reason })
 }
 
 /// The matches of `ranges` (byte ranges in `text`) that start on 0-based `line`, with their
@@ -721,7 +738,7 @@ async fn run_search(call: &Call, query: SearchQuery) -> IdeResult<(Vec<FileMatch
 
 async fn file_search(call: Call) -> IdeResult<Output> {
     let q = query(&call, "Glob pattern is empty")?;
-    let limit = limit(&call, DEFAULT_LIMIT)?;
+    let (page, limit) = page(&call, DEFAULT_LIMIT)?;
     let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
     let include_excluded = call.flag("includeExcluded", false)?;
     let glob = GlobSetBuilder::new()
@@ -759,9 +776,11 @@ async fn file_search(call: Call) -> IdeResult<Output> {
             Ok((found, more, walk.timed_out.get()))
         })
         .await?;
-    let items = paths.into_iter().map(|file_path| SearchItem { file_path, ..Default::default() }).collect();
+    let mut items: Vec<SearchItem> =
+        paths.into_iter().map(|file_path| SearchItem { file_path, ..Default::default() }).collect();
+    let next_offset = skip(page, &mut items, more);
     let partial_result_reason = timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON);
-    Output::json(SearchResult { items, more, partial_result_reason })
+    Output::json(SearchResult { items, more, next_offset, partial_result_reason })
 }
 
 struct Walk {
@@ -835,7 +854,7 @@ impl Walk {
 async fn symbol_search(call: Call) -> IdeResult<Output> {
     let started = Instant::now();
     let q = query(&call, "Search query is empty")?;
-    let limit = limit(&call, SYMBOL_SEARCH_DEFAULT_LIMIT)?;
+    let (page, limit) = page(&call, SYMBOL_SEARCH_DEFAULT_LIMIT)?;
     let around = context(&call)?;
     let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
     let external = call.flag("include_external", false)?;
@@ -886,6 +905,7 @@ async fn symbol_search(call: Call) -> IdeResult<Output> {
     }
     let more = items.len() > limit || timed_out;
     items.truncate(limit);
+    let next_offset = skip(page, &mut items, more);
     // Project files (relative paths, or absolute ones of content roots); library URIs are left out.
     let root = call.root().to_path_buf();
     let absolute = |item: &SearchItem| {
@@ -899,7 +919,7 @@ async fn symbol_search(call: Call) -> IdeResult<Output> {
     } else {
         timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON)
     };
-    Output::json(SearchResult { items, more, partial_result_reason })
+    Output::json(SearchResult { items, more, next_offset, partial_result_reason })
 }
 
 /// The language servers' workspace symbols, and whether `budget` ran out first; empty

crates/ide-host/src/mcp/symbols.rs

@@ -210,6 +210,7 @@ fn leads_declaration(line: &str, line_comment: Option<&str>) -> bool {
 pub fn find_references() -> Tool {
     Tool::new("find_references", "Find references using the language service and the IDE's project index. Positions are 1-based UTF-16. Reports incomplete results when analysis is still running.", |call| async move {
         let path = call.resolve_readable(&call.str("filePath")?).await?;
+        let page = super::page::Page::of(&call, REFERENCES_LIMIT)?;
         let line = call.opt_i64("line")?.ok_or_else(|| IdeError::invalid("missing line"))?;
         let column = call.opt_i64("column")?.ok_or_else(|| IdeError::invalid("missing column"))?;
         let project = call.project.clone();
@@ -244,14 +245,28 @@ pub fn find_references() -> Tool {
             }
         }
         positions(&mut value);
+        // `classified`, when there, goes with `locations` one to one.
+        if let serde_json::Value::Object(map) = &mut value {
+            let mut list = |key: &str| match map.remove(key) { Some(serde_json::Value::Array(items)) => items, _ => Vec::new() };
+            let (locations, classified) = (list("locations"), list("classified"));
+            let classified = page.take(classified, &mut serde_json::Map::new());
+            let locations = page.take(locations, map);
+            map.insert("locations".into(), locations.into());
+            map.insert("classified".into(), classified.into());
+        }
         Output::json(value)
     })
     .param(Param::required("filePath", ParamType::String, "Path relative to the project root"))
     .param(Param::required("line", ParamType::Integer, "1-based line"))
     .param(Param::required("column", ParamType::Integer, "1-based UTF-16 column"))
     .param(Param::optional("includeDeclaration", ParamType::Boolean, "Include declarations (default true)"))
+    .param(Param::optional("limit", ParamType::Integer, "References to return at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, super::page::OFFSET))
 }
 
+/// References `find_references` lists by default.
+const REFERENCES_LIMIT: usize = 100;
+
 fn mcp_position(text: &str, line: i64, column: i64) -> IdeResult<Pos> {
     if line < 1 || line > u32::MAX as i64 || column < 1 || column > u32::MAX as i64 {
         return Err(IdeError::invalid("line and column must be positive 1-based positions"));

crates/ide-host/src/mcp/vcs.rs

@@ -2,12 +2,13 @@
 // (mcpserver.vcs/src/com/intellij/mcpserver/toolsets/vcs/VcsToolset.kt), Apache-2.0.
 //! Version control: repositories and git status.
 
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use ide_core::{IdeError, IdeResult};
 use serde_json::{Value, json};
 use std::path::{Path, PathBuf};
 
-const STATUS_DEFAULT_LIMIT: i64 = 1000;
+const STATUS_DEFAULT_LIMIT: usize = 100;
 
 pub fn tools() -> Vec<Tool> {
     vec![get_repositories(), git_status(), git_diff()]
@@ -254,11 +255,7 @@ By default all Git repositories are returned.",
         |call| async move {
             let include_untracked = call.flag("includeUntracked", true)?;
             let include_ignored = call.flag("includeIgnored", false)?;
-            let limit = call.opt_i64("limit")?.unwrap_or(STATUS_DEFAULT_LIMIT);
-            if limit <= 0 {
-                return Err(IdeError::invalid("limit must be > 0"));
-            }
-            let limit = limit as usize;
+            let page = Page::of(&call, STATUS_DEFAULT_LIMIT)?;
             let host = call.host();
             let h = host.clone();
             let w = call.window.clone();
@@ -305,7 +302,8 @@ By default all Git repositories are returned.",
                 let count = |f: fn(&StatusEntry) -> bool| entries.iter().filter(|e| f(e)).count();
                 let listed: Vec<Value> = entries
                     .iter()
-                    .take(limit)
+                    .skip(page.offset)
+                    .take(page.limit)
                     .map(|e| {
                         let mut v = json!({
                             "pathRelativeToRepository": e.path.trim_end_matches('/'),
@@ -318,19 +316,24 @@ By default all Git repositories are returned.",
                         v
                     })
                     .collect();
-                repositories.push(json!({
+                let more = entries.len() > page.end();
+                let mut repository = json!({
                     "repositoryPathRelativeToProject": rel,
                     "currentBranch": branch,
                     "isClean": entries.is_empty(),
                     "totalEntries": entries.len(),
-                    "hasMoreEntries": entries.len() > listed.len(),
+                    "hasMoreEntries": more,
                     "stagedCount": count(StatusEntry::staged),
                     "unstagedCount": count(StatusEntry::unstaged),
                     "untrackedCount": count(StatusEntry::untracked),
                     "ignoredCount": count(StatusEntry::ignored),
                     "conflictedCount": count(StatusEntry::conflicted),
                     "entries": listed,
-                }));
+                });
+                if more {
+                    repository["nextOffset"] = page.end().into();
+                }
+                repositories.push(repository);
             }
             Output::json(json!({ "repositories": repositories }))
         },
@@ -342,7 +345,8 @@ By default all Git repositories are returned.",
     ))
     .param(Param::optional("includeUntracked", ParamType::Boolean, "Whether to include untracked files"))
     .param(Param::optional("includeIgnored", ParamType::Boolean, "Whether to include ignored files"))
-    .param(Param::optional("limit", ParamType::Integer, "Maximum number of entries returned per repository"))
+    .param(Param::optional("limit", ParamType::Integer, "Entries to return per repository at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
 }
 
 fn git_diff() -> Tool {

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

@@ -261,6 +261,18 @@ pub async fn fork(host: &Host, window: &str, task: String, turns: Option<u32>) -
     host.project(window)?.agents.fork(&task, turns).await
 }
 
+/// Creates a temporary side conversation of `source`: lives in memory only, never
+/// persisted, not listed.
+pub async fn create_ephemeral(
+    host: &Host,
+    window: &str,
+    request: NewAgentTask,
+    source: String,
+) -> IdeResult<AgentTask> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.create_ephemeral(request, &source).await
+}
+
 /// Drops the task's turns after its first `turns`; returns the message of the first dropped one.
 pub async fn rollback(host: &Host, window: &str, task: String, turns: u32) -> IdeResult<Option<AgentPrompt>> {
     host.require_trust(window)?;

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

@@ -3047,7 +3047,16 @@ impl PluginWorkspace for HostWorkspace {
             &project.root,
             &project.settings.effective(),
         );
-        if config.debug_adapter.is_none() {
+        if config.debug_adapter.is_none()
+            && let Some(language) = config.extras.params.get(super::run_detectors::DEBUG_LANGUAGE)
+        {
+            config.debug_adapter = project
+                .languages
+                .get(&ide_core::LanguageId::new(language.as_str()))
+                .and_then(|l| l.debugger)
+                .map(|d| d.adapter);
+        }
+        if config.debug_adapter.is_none() && !config.extras.params.contains_key(super::run_detectors::DEBUG_ATTACH) {
             let cwd = config.cwd.as_ref().map(|p| p.as_ref()).unwrap_or(&project.root);
             config.debug_adapter =
                 config.args.iter().map(|arg| cwd.join(arg)).filter(|path| path.is_file()).find_map(|path| {

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

@@ -415,6 +415,67 @@ fn validate_configurations(
         if let Some(cwd) = &c.cwd {
             ide_plugin::resolve_new_in_root(root, cwd).map_err(HostError::Invalid)?;
         }
+        validate_env(&c.env)?;
+        validate_debugger(c.debugger.as_ref())?;
+    }
+    Ok(())
+}
+
+/// Like `process` commands, a configuration only adds variables: one the IDE's own
+/// environment has (`PATH`, …) would change what the approved program runs.
+fn validate_env(env: &[(String, String)]) -> Result<(), HostError> {
+    if env.len() > 64 {
+        return Err(HostError::Invalid("at most 64 environment variables".into()));
+    }
+    let mut names = std::collections::BTreeSet::new();
+    for (name, value) in env {
+        if name.is_empty() || name.len() > 256 || name.contains(['=', '\0']) {
+            return Err(HostError::Invalid(format!("{name:?} is not an environment variable name")));
+        }
+        if value.len() > 4096 || value.contains('\0') {
+            return Err(HostError::Invalid(format!("the value of {name:?} is too long or holds a NUL")));
+        }
+        let key = if cfg!(windows) { name.to_ascii_uppercase() } else { name.clone() };
+        if !names.insert(key) || inherited_env(name) {
+            return Err(HostError::Invalid(format!(
+                "environment variable {name:?} is repeated or already set; only new variables may be added"
+            )));
+        }
+    }
+    Ok(())
+}
+
+fn inherited_env(name: &str) -> bool {
+    std::env::vars_os().any(|(inherited, _)| {
+        if cfg!(windows) { inherited.to_string_lossy().eq_ignore_ascii_case(name) } else { inherited == name }
+    })
+}
+
+/// Attach to Process kinds a configuration may attach to.
+pub(super) const ATTACH_KINDS: [&str; 5] = ["dotnet", "node", "python", "go", "native"];
+
+fn validate_debugger(debugger: Option<&ide_plugin::PluginDebugger>) -> Result<(), HostError> {
+    match debugger {
+        Some(ide_plugin::PluginDebugger::Launch { language }) => {
+            if language.is_empty()
+                || language.len() > 64
+                || !language.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '_' | '.'))
+            {
+                return Err(HostError::Invalid(format!("{language:?} is not a language id")));
+            }
+        }
+        Some(ide_plugin::PluginDebugger::AttachChild { kind, command_contains }) => {
+            if !ATTACH_KINDS.contains(&kind.as_str()) {
+                return Err(HostError::Invalid(format!(
+                    "attach-child kind {kind:?} is not one of {}",
+                    ATTACH_KINDS.join(", ")
+                )));
+            }
+            if command_contains.as_ref().is_some_and(|t| t.is_empty() || t.len() > 256 || t.contains('\0')) {
+                return Err(HostError::Invalid("attach-child command-contains must be 1-256 bytes".into()));
+            }
+        }
+        None => {}
     }
     Ok(())
 }
@@ -531,6 +592,52 @@ impl PluginHost {
     }
 }
 
+impl PluginHost {
+    /// The process an `attach-child` configuration's debugger attaches to: the first Attach to
+    /// Process candidate of its kind that `run` (a run of this configuration) started, waited
+    /// for while the run lasts, up to a minute. Only the run's own descendants are candidates.
+    pub fn debug_attach_target(
+        &self,
+        host: &crate::Host,
+        client: &str,
+        config: &str,
+        run: ide_core::RunId,
+    ) -> IdeResult<ide_dap::attach::AttachableProcess> {
+        use super::run_detectors::{DEBUG_ATTACH, DEBUG_ATTACH_CONTAINS};
+        let Some((plugin, id)) = config.strip_prefix(ide_run::EXTERNAL_PREFIX).and_then(|s| s.split_once(':')) else {
+            return Err(IdeError::invalid("not a plugin configuration"));
+        };
+        let workspace = self.shared.workspace().ok_or_else(IdeError::cancelled)?;
+        let owned = workspace.run_configuration(client, plugin, id).map_err(|e| IdeError::invalid(e.to_string()))?;
+        let kind = owned
+            .extras
+            .params
+            .get(DEBUG_ATTACH)
+            .filter(|k| ATTACH_KINDS.contains(&k.as_str()))
+            .ok_or_else(|| IdeError::invalid("this configuration does not attach to a process"))?
+            .clone();
+        let contains = owned.extras.params.get(DEBUG_ATTACH_CONTAINS).cloned();
+        let deadline = Instant::now() + Duration::from_secs(60);
+        loop {
+            let info = crate::ops::run::list(host).into_iter().find(|r| r.id == run && r.config_id == owned.id);
+            let Some(pid) = info.as_ref().filter(|r| r.running).and_then(|r| r.pid) else {
+                return Err(IdeError::not_found("the run ended before a process to debug started"));
+            };
+            let found = ide_dap::attach::attachable_descendants(pid)?.into_iter().find(|p| {
+                serde_json::to_value(p.kind).ok().and_then(|v| v.as_str().map(|k| k == kind)) == Some(true)
+                    && contains.as_ref().is_none_or(|t| p.command_line.contains(t.as_str()))
+            });
+            if let Some(process) = found {
+                return Ok(process);
+            }
+            if Instant::now() >= deadline {
+                return Err(IdeError::not_found(format!("no {kind} process started by the run within a minute")));
+            }
+            std::thread::sleep(Duration::from_millis(500));
+        }
+    }
+}
+
 /// Internal launch metadata; it is ignored after the original operation finishes.
 pub(super) const RUN_OPERATION: &str = "plugin.operation";
 impl PluginHost {
@@ -605,4 +712,52 @@ mod tests {
             matches!(validate_diff(&diff("a\0".into(), String::new())), Err(HostError::Invalid(m)) if m.contains("NUL"))
         );
     }
+
+    fn launch(
+        env: Vec<(&str, &str)>,
+        debugger: Option<ide_plugin::PluginDebugger>,
+    ) -> ide_plugin::PluginRunConfiguration {
+        ide_plugin::PluginRunConfiguration {
+            id: "app".into(),
+            name: "App".into(),
+            program: "tool".into(),
+            env: env.into_iter().map(|(k, v)| (k.into(), v.into())).collect(),
+            debugger,
+            ..Default::default()
+        }
+    }
+
+    #[test]
+    fn configurations_only_add_environment_variables() {
+        let root = std::env::temp_dir();
+        let ok = |c| validate_configurations(&root, &[c]).is_ok();
+        assert!(ok(launch(vec![("OPENIDEA_TEST_NEW_VARIABLE", "1")], None)));
+        let (inherited, _) = std::env::vars().next().expect("the test runs with an environment");
+        assert!(!ok(launch(vec![(inherited.as_str(), "x")], None)));
+        assert!(!ok(launch(vec![("A_B", "1"), ("A_B", "2")], None)));
+        for name in ["", "A=B", "A\0"] {
+            assert!(!ok(launch(vec![(name, "1")], None)), "{name:?}");
+        }
+        assert!(!ok(launch(vec![("OPENIDEA_TEST_NUL", "a\0")], None)));
+        let many: Vec<_> = (0..65).map(|i| (format!("OPENIDEA_TEST_{i}"), String::new())).collect();
+        let mut config = launch(vec![], None);
+        config.env = many;
+        assert!(!ok(config));
+    }
+
+    #[test]
+    fn configurations_name_a_language_or_an_attach_to_process_kind() {
+        use ide_plugin::PluginDebugger::{AttachChild, Launch};
+        let root = std::env::temp_dir();
+        let ok = |d| validate_configurations(&root, &[launch(vec![], Some(d))]).is_ok();
+        assert!(ok(Launch { language: "csharp".into() }));
+        assert!(!ok(Launch { language: String::new() }));
+        assert!(!ok(Launch { language: "c sharp".into() }));
+        for kind in ATTACH_KINDS {
+            assert!(ok(AttachChild { kind: kind.into(), command_contains: None }), "{kind}");
+        }
+        assert!(!ok(AttachChild { kind: "java".into(), command_contains: None }));
+        assert!(ok(AttachChild { kind: "dotnet".into(), command_contains: Some("Worker.dll".into()) }));
+        assert!(!ok(AttachChild { kind: "dotnet".into(), command_contains: Some(String::new()) }));
+    }
 }

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

@@ -57,6 +57,7 @@ pub const COMMANDS: &[&str] = &[
     "plugin_terminal_session_close",
     "plugin_terminal_session_spawn",
     "plugin_prepare_debug_run",
+    "plugin_debug_attach_target",
     "plugin_finish_operation",
     "plugin_content_tab_action",
     "plugin_post_events",
@@ -572,6 +573,15 @@ impl RemotePlugins {
             }
         });
         let h = host.clone();
+        d.add("plugin_debug_attach_target", move |c| {
+            let h = h.clone();
+            async move {
+                let plugins = alive(&h)?;
+                let (config, run) = (c.arg::<String>("config")?, c.arg("run")?);
+                blocking(move || plugins.debug_attach_target(&c.host, &c.window, &config, run)).await
+            }
+        });
+        let h = host.clone();
         d.add("plugin_finish_operation", move |c| {
             let h = h.clone();
             async move {

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

@@ -130,6 +130,11 @@ pub struct PluginRunDetection {
     pub(crate) project_pins: super::api::ProjectPins,
 }
 
+/// `RunConfig.extras.params` keys carrying an API 1.9 configuration's debugger.
+pub const DEBUG_LANGUAGE: &str = "debugLanguage";
+pub const DEBUG_ATTACH: &str = "debugAttach";
+pub const DEBUG_ATTACH_CONTAINS: &str = "debugAttachContains";
+
 pub(super) fn config_id(plugin: &str, detector: &str) -> String {
     format!("{EXTERNAL_PREFIX}{plugin}:{detector}")
 }
@@ -195,6 +200,19 @@ impl ExternalDetection for PluginRunDetection {
                 if let Some(framework) = &c.framework {
                     config.extras.params.insert("framework".into(), framework.clone());
                 }
+                config.env = c.env.iter().cloned().collect();
+                match &c.debugger {
+                    Some(ide_plugin::PluginDebugger::Launch { language }) => {
+                        config.extras.params.insert(DEBUG_LANGUAGE.into(), language.clone());
+                    }
+                    Some(ide_plugin::PluginDebugger::AttachChild { kind, command_contains }) => {
+                        config.extras.params.insert(DEBUG_ATTACH.into(), kind.clone());
+                        if let Some(text) = command_contains {
+                            config.extras.params.insert(DEBUG_ATTACH_CONTAINS.into(), text.clone());
+                        }
+                    }
+                    None => {}
+                }
                 configs.push(config);
             }
         }

crates/ide-host/src/trust.rs

@@ -342,6 +342,7 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
             | "clear_caches"
             | "clipboard_file_list"
             | "clipboard_has_files"
+            | "clipboard_has_image"
             | "clipboard_image"
             | "clipboard_set_file_list"
             | "clipboard_write_text"

crates/ide-host/tests/mcp.rs

@@ -110,6 +110,11 @@ async fn reads_unsaved_text_and_searches_the_overlay_with_a_limit() {
     let found = h.json("search_text", json!({"q":"needle","limit":2})).await;
     assert_eq!(found["items"].as_array().unwrap().len(), 2);
     assert_eq!(found["more"], true);
+    assert_eq!(found["nextOffset"], 2);
+    // The next page goes on where this one ended.
+    let every = h.json("search_text", json!({"q":"needle","limit":20})).await["items"].as_array().unwrap().clone();
+    let next = h.json("search_text", json!({"q":"needle","limit":2,"offset":2})).await;
+    assert_eq!(next["items"].as_array().unwrap()[..], every[2..every.len().min(4)]);
     let all = h.json("search_text", json!({"q":"fresh","limit":20})).await;
     assert_eq!(all["items"][0]["filePath"], "src/a.txt");
     // The matched line comes with the result (unsaved text included), and lines around it on request.
@@ -162,7 +167,9 @@ async fn window_reports_supply_editor_selection_and_problems_then_disappear_on_c
     assert_eq!(focused["selection"]["startColumn"], 3);
     let problems = h.json("get_file_problems", json!({"filePath":"src/a.txt","errorsOnly":false})).await;
     assert_eq!(problems["errors"][0]["description"], "reported warning");
-    assert_eq!(h.json("get_project_problems", json!({})).await["files"].as_array().unwrap().len(), 1);
+    assert_eq!(h.json("get_project_problems", json!({})).await["files"], json!([]), "errors only by default");
+    let all = h.json("get_project_problems", json!({"errorsOnly":false})).await;
+    assert_eq!((all["files"].as_array().unwrap().len(), &all["total"]), (1, &json!(1)));
     h.host.close_project("main");
     h.host.open_project("main", &h.root).unwrap();
     assert_eq!(h.json("get_all_open_file_paths", json!({})).await["openFiles"], json!([]));
@@ -287,6 +294,41 @@ async fn execution_requires_a_window_and_denial_never_runs_a_build() {
     assert!(error.contains("window closed"), "{error}");
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn run_configurations_are_listed_a_page_at_a_time_and_filtered() {
+    let h = Harness::new();
+    h.trust().await;
+    let saved = |name: &str, command: &str, env: &[(&str, &str)]| ide_run::RunConfig {
+        id: format!("user:{name}"),
+        name: name.into(),
+        kind: "shell".into(),
+        command: command.into(),
+        args: Vec::new(),
+        cwd: None,
+        env: env.iter().map(|(k, v)| ((*k).to_owned(), (*v).to_owned())).collect(),
+        detected: false,
+        is_test: false,
+        debug_adapter: None,
+        allow_parallel: false,
+        extras: Default::default(),
+    };
+    let configs =
+        [saved("build", "tsc", &[("MODE", "ci")]), saved("lint", "oxlint .", &[]), saved("test", "vitest", &[])];
+    ide_run::save_user_configs(&h.root, &configs).unwrap();
+    let all = h.json("get_run_configurations", json!({})).await;
+    let total = all["total"].as_u64().unwrap();
+    assert!(total >= 3, "{all}");
+    // A saved configuration's own environment is listed.
+    let build = all["configurations"].as_array().unwrap().iter().find(|c| c["name"] == "build").unwrap();
+    assert_eq!(build["environment"], json!({ "MODE": "ci" }));
+    let first = h.json("get_run_configurations", json!({"limit": 1})).await;
+    assert_eq!((first["configurations"].as_array().unwrap().len(), &first["nextOffset"]), (1, &json!(1)));
+    let lint = h.json("get_run_configurations", json!({"query": "OXLINT"})).await;
+    let found = lint["configurations"].as_array().unwrap();
+    assert!(!found.is_empty() && (found.len() as u64) < total, "{lint}");
+    assert!(found.iter().all(|c| c.to_string().to_lowercase().contains("oxlint")), "{lint}");
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn git_status_and_diff_on_a_temporary_repository() {
     let h = Harness::new();
@@ -308,6 +350,18 @@ async fn git_status_and_diff_on_a_temporary_repository() {
     std::fs::write(h.root.join("src/a.txt"), "changed\n").unwrap();
     let status = h.json("git_status", json!({"repositoryPathRelativeToProject":"."})).await;
     assert_eq!(status["repositories"][0]["unstagedCount"], 1);
+    // Two entries, one per page.
+    std::fs::write(h.root.join("src/new.txt"), "new\n").unwrap();
+    let page =
+        |offset: u64| h.json("git_status", json!({"repositoryPathRelativeToProject":".","limit":1,"offset":offset}));
+    let first = page(0).await["repositories"][0].clone();
+    assert_eq!(
+        (&first["totalEntries"], &first["hasMoreEntries"], &first["nextOffset"]),
+        (&json!(2), &json!(true), &json!(1))
+    );
+    let second = page(1).await["repositories"][0].clone();
+    assert_ne!(second["entries"][0], first["entries"][0]);
+    assert!(second.get("nextOffset").is_none(), "{second}");
     assert!(h.call("git_diff", json!({"filePath":"src/a.txt"})).await.contains("+changed"));
     assert!(h.call("git_diff", json!({})).await.contains("src/a.txt"));
     assert!(h.call("git_diff", json!({"staged":true})).await.is_empty());
@@ -610,6 +664,19 @@ async fn agent_commands_run_in_named_tabs_and_report_what_the_user_did() {
     assert!(from_start["output"].as_str().unwrap().contains("hello"), "one log across the tab's commands");
     let runs = h.json("list_runs", json!({})).await;
     assert_eq!(runs["runs"].as_array().unwrap().len(), 2, "{runs}");
+    // Newest first, brief, filtered by state and paged.
+    let newest = h.json("list_runs", json!({"limit": 1})).await;
+    assert_eq!(
+        (&newest["runs"][0]["name"], &newest["total"], &newest["nextOffset"]),
+        (&json!("_agent_server"), &json!(2), &json!(1))
+    );
+    assert!(newest["runs"][0].get("outputLength").is_none(), "{newest}");
+    assert_eq!(h.json("list_runs", json!({"state": "idle"})).await["total"], 2);
+    assert_eq!(h.json("list_runs", json!({"state": "running"})).await["total"], 0);
+    assert_eq!(h.json("list_runs", json!({"state": "stoppedByAgent"})).await["total"], 2);
+    assert_eq!(h.json("list_runs", json!({"state": "error"})).await["total"], 0);
+    let unknown = h.error("list_runs", json!({"state": "done"})).await;
+    assert!(unknown.contains("unknown state `done`"), "{unknown}");
     let missing = h.error("get_run_status", json!({"name": "nothing"})).await;
     assert!(missing.contains("no agent tab named `_agent_nothing`"), "{missing}");
 

crates/ide-host/tests/plugins.rs

@@ -6450,7 +6450,13 @@ fn api14_stage3_configurations_test_results_and_content_actions_use_real_exports
     let configs = f.host.run_detection().detect(&f.project);
     assert!(configs.iter().any(|c| c.id == "plugin:execution:dynamic"
         && c.is_test
-        && c.extras.params.get("framework").map(String::as_str) == Some("plugin")));
+        && c.extras.params.get("framework").map(String::as_str) == Some("plugin")
+        && c.env.get("OPENIDEA_EXECUTION_FIXTURE").map(String::as_str) == Some("1")
+        && c.extras.params.get("debugLanguage").map(String::as_str) == Some("python")));
+    let worker = configs.iter().find(|c| c.id == "plugin:execution:worker").unwrap();
+    assert_eq!(worker.extras.params.get("debugAttach").map(String::as_str), Some("dotnet"));
+    assert_eq!(worker.extras.params.get("debugAttachContains").map(String::as_str), Some("Worker.dll"));
+    assert!(worker.env.is_empty() && !worker.is_test);
     assert_eq!(
         f.host.parse_test_results("main", "plugin:execution:dynamic", "batch".into()).unwrap().unwrap().len(),
         3

crates/ide-host/tests/trust.rs

@@ -46,6 +46,7 @@ async fn application_commands_work_in_restricted_projects_and_without_a_project(
         "clear_caches",
         "clipboard_file_list",
         "clipboard_has_files",
+        "clipboard_has_image",
         "clipboard_image",
         "clipboard_set_file_list",
         "clipboard_write_text",

crates/ide-host/tests/vcs_flow.rs

@@ -207,3 +207,22 @@ async fn change_commit_branch_stash_and_merge_a_conflict() {
     assert!(f.status().await.is_empty());
     assert_eq!(std::fs::read_to_string(&lib_path).unwrap(), resolved);
 }
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn checkout_reports_a_branch_held_by_another_worktree() {
+    let f = Flow::new("rust-app").await;
+    let linked = f._tmp.path().join("linked");
+    git(&f.root, &["worktree", "add", "-q", "-b", "topic", linked.to_str().unwrap()]);
+
+    let outcome = ops::vcs::vcs_checkout(&f.host, WINDOW, None, "topic".into(), false, None).await.unwrap();
+    assert_eq!(
+        outcome,
+        ide_vcs::CheckoutOutcome::CheckedOutInWorktree {
+            branch: "topic".into(),
+            path: dunce::canonicalize(&linked).unwrap()
+        }
+    );
+    // Nothing changed: the project is still on main.
+    let branches = ops::vcs::vcs_branches(&f.host, WINDOW, None).await.unwrap();
+    assert!(branches.iter().any(|b| b.name == "main" && b.current), "{branches:?}");
+}

crates/ide-lsp/src/injections.rs

@@ -715,33 +715,35 @@ mod tests {
         server.set_diagnostics(a.path.clone(), vec![diag(2, 5, "a"), diag(0, 1, "outside"), diag(4, 6, "crosses")]);
         let items = server.set_diagnostics(b.path.clone(), vec![diag(7, 10, "b")]);
         mgr.emit_diagnostics(&server, b.path, items, Encoding::Utf16);
-        let latest = || {
-            events
-                .lock()
-                .iter()
-                .rev()
-                .find_map(|e| match e {
+        // The SQL server's failed launch reports its status from a runtime thread; while that
+        // thread drains the server's event queue, events emitted here reach the sink from it.
+        let latest = |want: &dyn Fn(&[ide_core::Diagnostic]) -> bool| {
+            let deadline = std::time::Instant::now() + Duration::from_secs(5);
+            loop {
+                let items = events.lock().iter().rev().find_map(|e| match e {
                     ide_core::IdeEvent::Diagnostics { path: p, source, items }
                         if p.0 == path && source == &server.name =>
                     {
                         Some(items.clone())
                     }
                     _ => None,
-                })
-                .unwrap()
+                });
+                match items {
+                    Some(items) if want(&items) => return items,
+                    _ if std::time::Instant::now() > deadline => panic!("latest host diagnostics: {items:?}"),
+                    _ => std::thread::sleep(Duration::from_millis(5)),
+                }
+            }
         };
-        assert_eq!(latest().iter().map(|d| d.message.as_str()).collect::<Vec<_>>().len(), 3);
+        let messages = |items: &[ide_core::Diagnostic]| items.iter().map(|d| d.message.clone()).collect::<Vec<_>>();
+        let merged = latest(&|items| items.len() == 3);
         assert!(
-            latest()
-                .iter()
-                .filter(|d| d.message != "native")
-                .all(|d| d.source.as_deref() == Some(server.name.as_str()))
+            merged.iter().filter(|d| d.message != "native").all(|d| d.source.as_deref() == Some(server.name.as_str()))
         );
         mgr.set_injections(host, 1, vec![injection(7, 10)]);
-        assert_eq!(latest().iter().map(|d| d.message.clone()).collect::<Vec<_>>(), ["native", "b"]);
+        latest(&|items| messages(items) == ["native", "b"]);
         mgr.set_injections(host, 1, vec![]);
-        assert_eq!(latest()[0].message, "native");
-        assert_eq!(latest().len(), 1);
+        latest(&|items| messages(items) == ["native"]);
         assert!(
             events.lock().iter().all(|e| !matches!(e, ide_core::IdeEvent::Diagnostics { path, .. } if reserved(path)))
         );

crates/ide-lsp/src/lib.rs

@@ -1767,6 +1767,38 @@ impl LspManager {
         }
     }
 
+    /// Library classes in `jar:` targets that have no cached sources jar: the official Kotlin
+    /// LSP decompiles them to signatures only (`/* compiled code */`). When jdtls is running,
+    /// the same class from its Java model instead, decompiled with method bodies and navigable.
+    /// Its documents belong to jdtls ([`Self::virtual_document`] records it).
+    async fn jdt_library_classes(&self, snap: &DocSnap, pos: Pos, locs: Vec<Location>) -> Vec<Location> {
+        let jar_class = |l: &Location| l.uri.as_deref().is_some_and(|u| u.starts_with("jar:") && u.ends_with(".class"));
+        if !locs.iter().any(jar_class)
+            || !self.servers.lock().iter().any(|s| s.name == jdtls::SERVER && s.running().is_some())
+        {
+            return locs;
+        }
+        let name = library_source::identifier_at(snap.text.line(pos.line as usize), pos.col).map(str::to_owned);
+        let mut out = Vec::with_capacity(locs.len());
+        for loc in locs {
+            let entry = loc.uri.as_deref().filter(|_| jar_class(&loc)).and_then(library_source::parse);
+            let Some(entry) = entry else {
+                out.push(loc);
+                continue;
+            };
+            let Ok(uri) = self.java_class_file(Path::new(""), Some((entry.jar, entry.entry))).await else {
+                out.push(loc);
+                continue;
+            };
+            let range = match (&name, self.virtual_document(&uri).await) {
+                (Some(name), Ok(doc)) => library_source::declaration_range(&doc.text, name),
+                _ => Range::default(),
+            };
+            out.push(Location { path: uri.clone().into(), range, uri: Some(uri) });
+        }
+        out
+    }
+
     async fn goto_in(
         &self,
         snap: &DocSnap,
@@ -1808,6 +1840,7 @@ impl LspManager {
                     let locs = library_sources(snap, &self.project_root, pos, locs).await;
                     self.note_virtual(&t.server, locs.iter().map(|l| l.uri.as_deref()));
                     self.note_arduino_sources(&t.server, &locs);
+                    let locs = self.jdt_library_classes(snap, pos, locs).await;
                     let locs = merge_locations(first, locs);
                     if !locs.is_empty() {
                         return Ok(locs);

crates/ide-lsp/tests/mock_server.rs

@@ -296,37 +296,48 @@ fn harness_configured(
     servers: &[(&str, Value)],
     adjust: impl Fn(&mut LanguageServerConfig),
 ) -> Harness {
+    harness_languages(&[(lang_id, ext, servers)], adjust)
+}
+
+/// A language as `(id, extension, servers)`.
+type MockLanguage<'a> = (&'a str, &'a str, &'a [(&'a str, Value)]);
+
+/// Several languages; documents open as the first.
+fn harness_languages(languages: &[MockLanguage<'_>], adjust: impl Fn(&mut LanguageServerConfig)) -> Harness {
     let dir = tempfile::tempdir().unwrap();
     // Edits and references report canonical paths.
     let root = dunce::canonicalize(dir.path()).unwrap();
-    let lang = LanguageConfig {
-        id: LanguageId::new(lang_id),
-        name: "Mock".into(),
-        extensions: vec![ext.into()],
-        filenames: vec![],
-        first_line: None,
-        line_comment: None,
-        block_comment: None,
-        indent: None,
-        ui_mode: None,
-        framework_ui_modes: Vec::new(),
-        framework_files: Vec::new(),
-        formatter: None,
-        scratch_template: None,
-        tree_sitter: None,
-        language_servers: servers
-            .iter()
-            .map(|(n, _)| {
-                let mut cfg = server_cfg(n);
-                adjust(&mut cfg);
-                cfg
-            })
-            .collect(),
-        debugger: None,
-    };
-    let registry = Arc::new(LanguageRegistry::from_configs(vec![lang]));
+    let configs = languages
+        .iter()
+        .map(|(lang_id, ext, servers)| LanguageConfig {
+            id: LanguageId::new(*lang_id),
+            name: "Mock".into(),
+            extensions: vec![ext.to_string()],
+            filenames: vec![],
+            first_line: None,
+            line_comment: None,
+            block_comment: None,
+            indent: None,
+            ui_mode: None,
+            framework_ui_modes: Vec::new(),
+            framework_files: Vec::new(),
+            formatter: None,
+            scratch_template: None,
+            tree_sitter: None,
+            language_servers: servers
+                .iter()
+                .map(|(n, _)| {
+                    let mut cfg = server_cfg(n);
+                    adjust(&mut cfg);
+                    cfg
+                })
+                .collect(),
+            debugger: None,
+        })
+        .collect();
+    let registry = Arc::new(LanguageRegistry::from_configs(configs));
     let launcher = Arc::new(MockLauncher::default());
-    for (name, caps) in servers {
+    for (name, caps) in languages.iter().flat_map(|(_, _, servers)| servers.iter()) {
         *launcher.state(name).caps.lock() = caps.clone();
     }
     let events = Arc::new(Mutex::new(Vec::new()));
@@ -335,7 +346,7 @@ fn harness_configured(
         Arc::new(move |e: IdeEvent| events.lock().push(e))
     };
     let mgr = LspManager::with_launcher(root.clone(), registry, sink, launcher.clone());
-    Harness { _dir: dir, root, mgr, launcher, events, lang: LanguageId::new(lang_id) }
+    Harness { _dir: dir, root, mgr, launcher, events, lang: LanguageId::new(languages[0].0) }
 }
 
 impl Harness {
@@ -2946,6 +2957,63 @@ async fn library_classes_in_jars_open_as_their_source_or_decompiled() {
     assert_eq!(asked[0], json!({ "command": "decompile", "arguments": [thing] }));
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn library_classes_without_sources_open_decompiled_by_a_running_jdtls() {
+    use std::io::Write;
+    let repo = tempfile::tempdir().unwrap();
+    let jar = dunce::canonicalize(repo.path()).unwrap().join("acme/lib/1.0/lib-1.0.jar");
+    std::fs::create_dir_all(jar.parent().unwrap()).unwrap();
+    let mut zip = zip::ZipWriter::new(std::fs::File::create(&jar).unwrap());
+    zip.start_file("acme/Thing.class", zip::write::SimpleFileOptions::default()).unwrap();
+    zip.write_all(b"\0").unwrap();
+    zip.finish().unwrap();
+    let class = format!("jar://{}!/acme/Thing.class", uri_of(&jar).trim_start_matches("file://"));
+    let escaped = jar.to_string_lossy().replace('/', "%5C/");
+    let jdt = format!("jdt://contents/lib-1.0.jar/acme/Thing.class?=app/{escaped}%3Cacme%28Thing.class");
+    let decompiled =
+        "package acme;\n\npublic class Thing {\n   public void run() {\n      System.out.println();\n   }\n}\n";
+
+    let mut kotlin = incremental_caps();
+    kotlin["executeCommandProvider"] = json!({ "commands": ["decompile"] });
+    let mut java = incremental_caps();
+    java["workspaceSymbolProvider"] = json!(true);
+    let h =
+        harness_languages(&[("kotlin", "kt", &[("kotlin-lsp", kotlin)]), ("java", "java", &[("jdtls", java)])], |_| {});
+    let (doc, _) = h.open("Main.kt", "val thing = Thing()\n");
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    let k = h.launcher.state("kotlin-lsp");
+    k.respond(
+        "textDocument/definition",
+        json!({ "uri": class, "range": {"start":{"line":0,"character":6},"end":{"line":0,"character":11}} }),
+    );
+    let r = json!({"start":{"line":2,"character":13},"end":{"line":2,"character":18}});
+
+    // jdtls not running: the Kotlin server's own target and decompiler.
+    let defs = h.mgr.goto(doc, Pos::new(0, 14), GotoKind::Definition).await.unwrap();
+    assert_eq!(defs[0].uri.as_deref(), Some(class.as_str()));
+
+    let path = h.root.join("Sample.java");
+    std::fs::write(&path, "class Sample {}").unwrap();
+    h.mgr.did_open(DocId::next(), &path, &LanguageId::new("java"), 1, "class Sample {}");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let j = h.launcher.state("jdtls");
+    j.respond(
+        "workspace/symbol",
+        json!([{ "name": "Thing", "kind": 5, "containerName": "acme", "location": { "uri": jdt, "range": r } }]),
+    );
+    j.respond("java/classFileContents", json!(decompiled));
+
+    let defs = h.mgr.goto(doc, Pos::new(0, 14), GotoKind::Definition).await.unwrap();
+    assert_eq!(
+        defs,
+        vec![ide_core::Location { path: jdt.clone().into(), range: rng(2, 13, 2, 18), uri: Some(jdt.clone()) }]
+    );
+    assert_eq!(j.requested("workspace/symbol")[0]["query"], "acme.Thing");
+    let vd = h.mgr.virtual_document(&jdt).await.unwrap();
+    assert_eq!(vd.text, decompiled);
+    assert!(k.requested("workspace/executeCommand").is_empty(), "the Kotlin stub is not asked for");
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn alternative_java_server_uses_lsp_without_jdt_commands() {
     let h = harness_for("java", "java", &[("kmp-lsp", incremental_caps())], &[]);

crates/ide-plugin/src/execution.rs

@@ -61,6 +61,24 @@ pub struct PluginRunConfiguration {
     pub cwd: Option<String>,
     pub test: bool,
     pub framework: Option<String>,
+    /// API 1.9: variables added to the run's environment.
+    #[serde(default)]
+    pub env: Vec<(String, String)>,
+    /// API 1.9: how Debug starts the configuration.
+    #[serde(default)]
+    pub debugger: Option<PluginDebugger>,
+}
+
+/// How Debug starts a plugin configuration (API 1.9 `launch-configurations.debugger`).
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase", tag = "type")]
+pub enum PluginDebugger {
+    /// `program` under the debugger of this language id.
+    #[serde(rename_all = "camelCase")]
+    Launch { language: String },
+    /// Run, then attach to the first matching process the run starts.
+    #[serde(rename_all = "camelCase")]
+    AttachChild { kind: String, command_contains: Option<String> },
 }
 
 /// RunExited data exchanged with the IDE.

crates/ide-plugin/src/runtime.rs

@@ -36,6 +36,7 @@ use wasmtime::{Config, Engine, Store, StoreLimits, StoreLimitsBuilder, UpdateDea
 use wasmtime_wasi::p2::pipe::MemoryOutputPipe;
 use wasmtime_wasi::{WasiCtx, WasiCtxView, WasiView};
 
+use crate::wit_host::launch_configurations_bindings::exports::openidea::plugin::launch_configurations as wit_launch;
 use crate::wit_host::run_configurations_bindings::exports::openidea::plugin::run_configurations as wit_configs;
 use crate::wit_host::test_results_bindings::exports::openidea::plugin::test_results as wit_tests;
 use bindings::openidea::plugin::events as wit_events;
@@ -55,7 +56,7 @@ use views_bindings::exports::openidea::plugin::view_provider as wit_view;
 use views_bindings::openidea::plugin::view_types as wit_vt;
 
 /// The API version of the world above, `major.minor` of [`host_api`].
-pub const API_VERSION: &str = "1.8";
+pub const API_VERSION: &str = "1.9";
 const EPOCH_TICK: Duration = Duration::from_millis(10);
 pub(crate) const MAX_TEXT: usize = 1 << 20;
 pub(crate) const MAX_TITLE: usize = 256;
@@ -1008,6 +1009,7 @@ struct Exports {
     inlay: Option<wit_inlay::Guest>,
     endpoints: Option<wit_endpoints::Guest>,
     run_configurations: Option<wit_configs::Guest>,
+    launch_configurations: Option<wit_launch::Guest>,
     test_results: Option<wit_tests::Guest>,
     mcp: Option<crate::wit_host::mcp_bindings::exports::openidea::plugin::mcp_provider::Guest>,
 }
@@ -1147,6 +1149,7 @@ impl Runtime {
         let inlay_indices = wit_inlay::GuestIndices::new(&pre).ok();
         let endpoint_indices = wit_endpoints::GuestIndices::new(&pre).ok();
         let configs_indices = wit_configs::GuestIndices::new(&pre).ok();
+        let launch_indices = wit_launch::GuestIndices::new(&pre).ok();
         let tests_indices = wit_tests::GuestIndices::new(&pre).ok();
         let validation_indices = wit_rtv::GuestIndices::new(&pre).ok();
         let lf_indices = wit_lf::GuestIndices::new(&pre).ok();
@@ -1157,6 +1160,8 @@ impl Runtime {
         let mcp = mcp_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let run_configurations =
             configs_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
+        let launch_configurations =
+            launch_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let test_results = tests_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let language_features = lf_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let injections = inj_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
@@ -1230,6 +1235,7 @@ impl Runtime {
                 inlay,
                 endpoints,
                 run_configurations,
+                launch_configurations,
                 test_results,
                 mcp,
                 file_actions,
@@ -1269,34 +1275,67 @@ impl Runtime {
         .map(|r| r.map_err(|message| clip(message, 4096)))
     }
 
-    /// Complete configurations from the optional API 1.4 export.
+    /// Complete configurations from the optional API 1.9 export, else the API 1.4 one.
     pub fn run_configurations(
         &mut self,
         root: String,
         timeout: Duration,
     ) -> Result<Vec<crate::PluginRunConfiguration>, CallError> {
-        if self.exports.run_configurations.is_none() {
-            return Err(CallError::missing_export("run-configurations"));
-        }
         let invocation = Invocation { workspace_root: Some(root.clone().into()), ..Default::default() };
-        let items = self.call(invocation, timeout, |e, store| {
-            e.run_configurations.as_ref().unwrap().call_configurations(store, &root)
-        })?;
-        if items.len() > 1000 {
-            return Err(CallError::Guest(GuestError::Invalid("too many run configurations".into())));
-        }
-        Ok(items
-            .into_iter()
-            .map(|c| crate::PluginRunConfiguration {
-                id: c.id,
-                name: c.name,
-                program: c.program,
-                args: c.args,
-                cwd: c.cwd,
-                test: c.test,
-                framework: c.framework,
-            })
-            .collect())
+        let items: Vec<crate::PluginRunConfiguration> = if self.exports.launch_configurations.is_some() {
+            let items = self.call(invocation, timeout, |e, store| {
+                e.launch_configurations.as_ref().unwrap().call_configurations(store, &root)
+            })?;
+            if items.len() > 1000 {
+                return Err(CallError::Guest(GuestError::Invalid("too many run configurations".into())));
+            }
+            items
+                .into_iter()
+                .map(|c| crate::PluginRunConfiguration {
+                    id: c.id,
+                    name: c.name,
+                    program: c.program,
+                    args: c.args,
+                    cwd: c.cwd,
+                    test: c.test,
+                    framework: c.framework,
+                    env: c.env,
+                    debugger: match c.debugger {
+                        Some(wit_launch::Debugger::Launch(language)) => {
+                            Some(crate::PluginDebugger::Launch { language })
+                        }
+                        Some(wit_launch::Debugger::AttachChild(a)) => Some(crate::PluginDebugger::AttachChild {
+                            kind: a.kind,
+                            command_contains: a.command_contains,
+                        }),
+                        Some(wit_launch::Debugger::Other(_)) | None => None,
+                    },
+                })
+                .collect()
+        } else if self.exports.run_configurations.is_some() {
+            let items = self.call(invocation, timeout, |e, store| {
+                e.run_configurations.as_ref().unwrap().call_configurations(store, &root)
+            })?;
+            if items.len() > 1000 {
+                return Err(CallError::Guest(GuestError::Invalid("too many run configurations".into())));
+            }
+            items
+                .into_iter()
+                .map(|c| crate::PluginRunConfiguration {
+                    id: c.id,
+                    name: c.name,
+                    program: c.program,
+                    args: c.args,
+                    cwd: c.cwd,
+                    test: c.test,
+                    framework: c.framework,
+                    ..Default::default()
+                })
+                .collect()
+        } else {
+            return Err(CallError::missing_export("run-configurations"));
+        };
+        Ok(items)
     }
     /// Selects tests under the same budget as the test parser.
     pub fn select_tests(

crates/ide-plugin/src/wit_host.rs

@@ -2254,6 +2254,11 @@ impl bindings::openidea::plugin::run::Host for StoreData {
 pub(crate) mod run_configurations_bindings {
     wasmtime::component::bindgen!({ world: "configurations-provider", path: "../../wit" });
 }
+pub(crate) mod launch_configurations_bindings {
+    wasmtime::component::bindgen!({ world: "launch-configurations-provider", path: "../../wit",
+        with: { "openidea:plugin/types": super::bindings::openidea::plugin::types },
+    });
+}
 pub(crate) mod test_results_bindings {
     wasmtime::component::bindgen!({ world: "test-results-provider", path: "../../wit",
         with: { "openidea:plugin/types": super::bindings::openidea::plugin::types },

crates/ide-plugin/tests/api_compat.rs

@@ -91,15 +91,15 @@ fn the_sdk_carries_the_hosts_wit() {
 
 #[test]
 fn the_version_check_runs_compatible_components_and_explains_the_rest() {
-    let host = v("1.8.0");
-    for ok in ["1.0.0", "1.3.0", "1.4.7", "1.5.0", "1.6.0", "1.7.0", "1.8.0", "1.0.0-rc.1"] {
+    let host = v("1.9.0");
+    for ok in ["1.0.0", "1.3.0", "1.4.7", "1.5.0", "1.6.0", "1.7.0", "1.8.0", "1.9.0", "1.0.0-rc.1"] {
         assert_eq!(check_api(&v(ok), &host), Ok(()), "{ok}");
     }
-    let newer = check_api(&v("1.9.0"), &host).unwrap_err();
-    assert!(newer.contains("1.9") && newer.contains("update OpenIDEA"), "{newer}");
+    let newer = check_api(&v("1.10.0"), &host).unwrap_err();
+    assert!(newer.contains("1.10") && newer.contains("update OpenIDEA"), "{newer}");
     assert!(check_api(&v("2.0.0"), &host).unwrap_err().contains("update OpenIDEA"));
     let older = check_api(&v("0.2.0"), &host).unwrap_err();
-    assert!(older.contains("rebuild it with the 1.8 SDK"), "{older}");
+    assert!(older.contains("rebuild it with the 1.9 SDK"), "{older}");
     // 0.x: every minor is its own API.
     assert_eq!(check_api(&v("0.2.0"), &v("0.2.5")), Ok(()));
     assert!(check_api(&v("0.1.0"), &v("0.2.0")).is_err());

crates/ide-plugin/tests/fixtures/api14/dist/plugin.wasm.sources

@@ -1 +1 @@
-0b77e7a414ec3b0dd1f41e5658b981f059dd842743dbe2f06e5d428f5b9570f9
+a3d2511f30277245a8cb9673c4d8a948a8a025b8b9149d5015bed5137a98ccdd

crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources

@@ -1 +1 @@
-6f7d6527837c8e5c86c377479cceef5116decd61666b28f36dd11332e36e9934
+dad3edad99ad85234aa612bbc1f3a66e50361189e54038b91674703815f049cc

crates/ide-plugin/tests/fixtures/data-tools/dist/plugin.wasm.sources

@@ -1 +1 @@
-c1ac86a5b4d45b55013e6e00dcb83deda33b759ecc366c3fdf57739bdd22cbff
+918af7d4d8bc302621b9b68070a56930813b1fc2ba235d89de4e56c53eaba5bd

crates/ide-plugin/tests/fixtures/detail-views/dist/plugin.wasm.sources

@@ -1 +1 @@
-e4d8d8f5f5849b912b2c0ebee6b91d60796c3070929d7698323e8ce4f200a38a
+7a140c2255a3d251a5ab9079bec953cccc4408727b067b49da47cf8fb27d8cb8

crates/ide-plugin/tests/fixtures/diagnostics/dist/plugin.wasm.sources

@@ -1 +1 @@
-e2e2fc44ad9cae9cf26a5bf706768d3786502f23db6994dc29695deb249ed73f
+ef41934bd0b67f76a17ef321b44c172496314c9fea6b46b4cd2f1d0f4b96907d

crates/ide-plugin/tests/fixtures/endpoints/dist/plugin.wasm.sources

@@ -1 +1 @@
-61e1f0c43bbfddc35dcf40685169eb273777ddca13da534626e1699b47e8eac3
+c6dc1ae00d9f3d936f4bf5ff110915050cb503ac06982bdc48e967deac84a913

crates/ide-plugin/tests/fixtures/execution/dist/plugin.wasm.sources

@@ -1 +1 @@
-2ea1c1693db8638db996c9c47597f0c1635ef0a9c7dfb33685c515b7af95e6a6
+25a782556dd6bbf8ed1ad7b50b9b55685f074d80220af08f3bd9cb12cf07f74e

crates/ide-plugin/tests/fixtures/execution/plugin.toml

@@ -1,7 +1,7 @@
 id = "execution"
 name = "Plugin execution tests"
 version = "0.1.0"
-engines.openidea = "^1.5"
+engines.openidea = "^1.9"
 wasm = "dist/plugin.wasm"
 activation = ["on-command:*"]
 [capabilities]

crates/ide-plugin/tests/fixtures/execution/src/lib.rs

@@ -114,17 +114,37 @@ impl Plugin for Execution {
         host::storage::set("events", &serde_json::to_string(&received).unwrap()).unwrap();
     }
 }
-impl RunConfigurations for Execution {
-    fn configurations(&mut self, _: &str) -> Vec<PluginRunConfiguration> {
-        vec![PluginRunConfiguration {
-            id: "dynamic".into(),
-            name: "Dynamic tests".into(),
-            program: "execution-tool".into(),
-            args: vec!["test".into()],
-            test: true,
-            framework: Some("plugin".into()),
-            ..Default::default()
-        }]
+impl LaunchConfigurations for Execution {
+    fn launch_configurations(&mut self, _: &str) -> Vec<PluginLaunchConfiguration> {
+        vec![
+            PluginLaunchConfiguration {
+                config: PluginRunConfiguration {
+                    id: "dynamic".into(),
+                    name: "Dynamic tests".into(),
+                    program: "execution-tool".into(),
+                    args: vec!["test".into()],
+                    test: true,
+                    framework: Some("plugin".into()),
+                    ..Default::default()
+                },
+                env: vec![("OPENIDEA_EXECUTION_FIXTURE".into(), "1".into())],
+                debugger: Some(Debugger::Launch { language: "python".into() }),
+            },
+            PluginLaunchConfiguration {
+                config: PluginRunConfiguration {
+                    id: "worker".into(),
+                    name: "Worker".into(),
+                    program: "execution-tool".into(),
+                    args: vec!["start".into()],
+                    ..Default::default()
+                },
+                env: Vec::new(),
+                debugger: Some(Debugger::AttachChild {
+                    kind: "dotnet".into(),
+                    command_contains: Some("Worker.dll".into()),
+                }),
+            },
+        ]
     }
 }
 impl TestResults for Execution {
@@ -181,4 +201,4 @@ impl RunTargetValidation for Execution {
         }
     }
 }
-register_plugin!(Execution, run_configurations, test_results, run_target_validation);
+register_plugin!(Execution, launch_configurations, test_results, run_target_validation);

crates/ide-plugin/tests/fixtures/ext-owner/dist/plugin.wasm.sources

@@ -1 +1 @@
-3c788f6092b229484a5d94fd0e6f4651afc88dd0ab1b22b067d84614a6a0c85e
+f58b5f68d56611c3d15f69ff8e73e6e65d84e55d14c9bae00ed50b346460adfa

crates/ide-plugin/tests/fixtures/file-templates/dist/plugin.wasm.sources

@@ -1 +1 @@
-18273599cc459833d6a30185a5f0ba127cdb4e22bc054a973571e530eb3a85ca
+749bff2d051984edf65590494ef803225dfccd03d032de140974d8e984683ac1

crates/ide-plugin/tests/fixtures/files-events/dist/plugin.wasm.sources

@@ -1 +1 @@
-c9fafba362fa0745d7ee1685efe5582d432510003c04c98100eddd557bd1e2cf
+50c609ebf387b400a01ea28e6ccf0f3de2ff7a5eedbb47c0a4bc40d05e3aaade

crates/ide-plugin/tests/fixtures/grouped-views/dist/plugin.wasm.sources

@@ -1 +1 @@
-4121009913709edeca8c5cb52d88dfcc2b16867bc06859768f73c17cf9c456a2
+c2350d0277636285b182d1484d01d706c3116ef5e28917ddeb24ca78bac251ba

crates/ide-plugin/tests/fixtures/hello/dist/plugin.wasm.sources

@@ -1 +1 @@
-b55bd202a06f5643c4f70abb6fb473fbe53af657f4e21a6d13581a23a726e085
+3aaa2a7655189a1e4da55a86fb30fdfde29a5b6ad65de53a78b18df30eeb97f3

crates/ide-plugin/tests/fixtures/hover/dist/plugin.wasm.sources

@@ -1 +1 @@
-11a12228df67f9b94bd52375b5dddb2d955f7e5f88d7f9ea0a430b1db128f6ca
+975ead22afb4c5bc5c79799b76c1d3a683b572b906e3bade94944319920f7f84

crates/ide-plugin/tests/fixtures/indexer/dist/plugin.wasm.sources

@@ -1 +1 @@
-553ce6c57052f8ff2ea2526e88762d5a0aee2489cda192fc7ab708766078ccf7
+b849aeca8e5d6b6ede216e372cfc019bac08774006e11ed81d272f67770adc17

crates/ide-plugin/tests/fixtures/inlay-hints/dist/plugin.wasm.sources

@@ -1 +1 @@
-7b43f8a2a06d7b2952f8d46727a4cce524fb2bdecee1035dad9c767261d276d0
+79505f2677e5f19374a3ed46cccdc1ed8d3092a3c43e3154e8cfd73063533251

crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm.sources

@@ -1 +1 @@
-e994c69fda5eef94ae85d6dac5aec3d04fb6811c35c446c9d33236a449bd1c6c
+f7f43d46ebd545cc4c52d859c4307d08bb95b3187a4b947704e37c27cf0f4fa0

crates/ide-plugin/tests/fixtures/language-features/dist/plugin.wasm.sources

@@ -1 +1 @@
-c37f6a7ea9018ca636d0fd486a9d91cd397158615410de9b837ca9b8f9f593b7
+491e8e713e51045ebef81c4f07ed5475ed41688e88ac47ee26d13f2bc5c53b49

crates/ide-plugin/tests/fixtures/misbehave/dist/plugin.wasm.sources

@@ -1 +1 @@
-1b298dfa5c1f2163d609ef0ccc3d42fafe78e69326002effe53abc4b82974749
+63b2f6007782c9d3498c86505a6c107b70f09d90678c79cf16c859ecbf349e70

crates/ide-plugin/tests/fixtures/misbehave/src/lib.rs

@@ -5,9 +5,9 @@ wit_bindgen::generate!({
     inline: "
         package fixture:misbehave;
         world misbehave {
-            include openidea:plugin/plugin-syntax@1.8.0;
-            export openidea:plugin/providers@1.8.0;
-            export openidea:plugin/file-actions@1.8.0;
+            include openidea:plugin/plugin-syntax@1.9.0;
+            export openidea:plugin/providers@1.9.0;
+            export openidea:plugin/file-actions@1.9.0;
         }
     ",
     path: "../../../../../wit",

crates/ide-plugin/tests/fixtures/path-events/dist/plugin.wasm.sources

@@ -1 +1 @@
-1e11a95e0909d18308d21a9a8448f8b2e427d240d5d8cd13d8ddbe6ba5009237
+3d1f2451dee8bba3cc874f497bcea909fa9bd58ae605dc1d74b4298b4b11ed94

crates/ide-plugin/tests/fixtures/private-dir/dist/plugin.wasm.sources

@@ -1 +1 @@
-d5cd77130cc97cffdbc742f04e3e1196f14160107b636806c6ef3c9b40724e84
+26a2b15b9354fa0ba2bf5934114bfdd20f7906c4a67497d013146cc6b3fc9643

crates/ide-plugin/tests/fixtures/semantic-tokens/dist/plugin.wasm.sources

@@ -1 +1 @@
-a0f74430b0a7d9ff48524d7aae4f8a0bd0fc60511e2a951dde9991b9bf7d15a9
+c9ef2cf7b6e8f3204f8ee382d7a381a5190b1e812e11d51bd1262c3d429a315f

crates/ide-plugin/tests/fixtures/settings-pages/dist/plugin.wasm.sources

@@ -1 +1 @@
-65508f6e25bd0efc85820ae7d0f9037b58c778fa61e8498c5b9a5055cc38f6fc
+b07cc854c1302fd5bfd29fb3037732c7439efde606fc57295b2c0f94602a1077

crates/ide-plugin/tests/fixtures/storage/dist/plugin.wasm.sources

@@ -1 +1 @@
-c86ed41d68c132f72eb8b5794f31b975492e5ad42e41b7823d1bf28ba118a262
+12c4004f118070d0f37125ac32639ab9f332d59cc4585e74a8af61e3e6c5c1e8

crates/ide-plugin/tests/fixtures/symbols/dist/plugin.wasm.sources

@@ -1 +1 @@
-3da1a09906d803234016b3f9c30a88b9b40bf3187fc73840ff60a2e05f504b48
+7517da988ab8cacaa3abf7645274a84e364de582ea9edf60a63926b1442d1581

crates/ide-plugin/tests/fixtures/tables/dist/plugin.wasm.sources

@@ -1 +1 @@
-39e7a805120ce6433750c32b1d670b3caba990f7b15aea866a29c23b01cba708
+6e045ee3fcaa655bae773774e48e3eeb9d97ae9d8db1f52bf76c38459dcecb3f

crates/ide-plugin/tests/fixtures/web-content/dist/plugin.wasm.sources

@@ -1 +1 @@
-5ec9be607955ce2aa4d921884df17c49af3ce98945f8fa641cec9a7f1b4d8384
+69bb92e6e24e54458978a316c465d17b93d9ce9613cd26d7d6de9a1cef9b9447

crates/ide-plugin/tests/fixtures/web-log/dist/plugin.wasm.sources

@@ -1 +1 @@
-f05df5c2faf1718ba9702be4d979c367ea8445a854794bb21e8e36b211f18122
+fc64a30e9d3b46275a6480641454b367b5082aea82da23a11b57106aa02387e1

crates/ide-plugin/tests/fixtures/web-pty/dist/plugin.wasm.sources

@@ -1 +1 @@
-548cb8321b63b0685049fcf796dbc8390fcb22f3c1ffcfa09452e5a63382d27d
+e6f3b5a4d81e62240fa1de4d1624b3706f145d47c014a1a2ed2b899cab24e0e4

crates/ide-vcs/src/lib.rs

@@ -496,6 +496,9 @@ pub struct CheckoutOptions {
     /// Required when checking out a remote branch whose local namesake is ahead of it.
     #[serde(default)]
     pub diverged: Option<DivergedLocal>,
+    /// Check the branch out even though another worktree has it checked out.
+    #[serde(default)]
+    pub ignore_other_worktrees: bool,
 }
 
 /// Result of [`Repo::checkout_with`]; the non-`Done` variants other than `Conflicts`
@@ -522,6 +525,12 @@ pub enum CheckoutOutcome {
     Conflicts {
         files: Vec<String>,
     },
+    /// Git refused: `branch` is checked out in the linked worktree at `path`. Nothing
+    /// changed; the branch can be worked on there.
+    CheckedOutInWorktree {
+        branch: String,
+        path: PathBuf,
+    },
 }
 
 /// HEAD before and after a history rewrite, for its Undo.

crates/ide-vcs/src/write.rs

@@ -765,6 +765,18 @@ fn overwritten_untracked(stderr: &str) -> Option<Vec<String>> {
     listed_files(stderr, "untracked working tree files would be")
 }
 
+/// The branch git refused to check out or update because another worktree has it, from
+/// its error message: a switch says `'<branch>' is already used by worktree at '<path>'`,
+/// a forced update says `cannot force update the branch '<branch>' used by worktree at
+/// '<path>'`; git before 2.42 says `'<branch>' is already checked out at '<path>'`.
+fn branch_of_other_worktree(stderr: &str) -> Option<(String, String)> {
+    const MARKERS: [&str; 3] =
+        ["' is already used by worktree at '", "' used by worktree at '", "' is already checked out at '"];
+    let (before, path) = stderr.lines().find_map(|l| MARKERS.iter().find_map(|m| l.split_once(m)))?;
+    let branch = before.rsplit('\'').next()?.to_string();
+    Some((branch, path.strip_suffix('\'').unwrap_or(path).to_string()))
+}
+
 fn listed_files(stderr: &str, header: &str) -> Option<Vec<String>> {
     let mut lines = stderr.lines().skip_while(|l| !l.contains(header));
     lines.next()?;
@@ -805,12 +817,18 @@ pub(crate) fn checkout_with(
     if options.mode == CheckoutMode::Force {
         args.push("--discard-changes".into());
     }
+    if options.ignore_other_worktrees {
+        args.push("--ignore-other-worktrees".into());
+    }
     let argv: Vec<&str> = args.iter().map(String::as_str).collect();
     let out = cli::run_raw(r.root(), &argv, None)?;
     if out.code == Some(0) {
         return Ok(CheckoutOutcome::Done);
     }
     let stderr = String::from_utf8_lossy(&out.stderr);
+    if let Some((branch, path)) = branch_of_other_worktree(&stderr) {
+        return Ok(CheckoutOutcome::CheckedOutInWorktree { branch, path: path.into() });
+    }
     if let Some(files) = overwritten_untracked(&stderr) {
         return Ok(CheckoutOutcome::UntrackedFiles { files });
     }
@@ -893,7 +911,14 @@ pub(crate) fn create_branch(
         args.extend(["--", name]);
     }
     args.extend(start);
-    run(r.root(), &args, None).map(|_| ())
+    let out = cli::run_raw(r.root(), &args, None)?;
+    if out.code == Some(0) {
+        return Ok(());
+    }
+    if let Some((branch, path)) = branch_of_other_worktree(&String::from_utf8_lossy(&out.stderr)) {
+        return Err(IdeError::invalid(format!("branch '{branch}' is already checked out in worktree at '{path}'")));
+    }
+    Err(cli::failure(&args, &out.stderr, &out.stdout, out.code))
 }
 
 /// Whether `start` is a remote-tracking branch with another name than the new branch
@@ -1479,7 +1504,22 @@ fn decode_diff(bytes: &[u8], encoding: TextEncoding) -> String {
 
 #[cfg(test)]
 mod tests {
-    use super::append_revision;
+    use super::{append_revision, branch_of_other_worktree};
+
+    #[test]
+    fn the_worktree_holding_a_branch_is_read_from_each_git_wording() {
+        let held = |b: &str, p: &str| Some((b.to_string(), p.to_string()));
+        assert_eq!(
+            branch_of_other_worktree("fatal: 'topic' is already used by worktree at '/w/t'\n"),
+            held("topic", "/w/t")
+        );
+        assert_eq!(
+            branch_of_other_worktree("fatal: cannot force update the branch 'topic' used by worktree at '/w/t'"),
+            held("topic", "/w/t")
+        );
+        assert_eq!(branch_of_other_worktree("fatal: 'a/b' is already checked out at '/w/t'"), held("a/b", "/w/t"));
+        assert_eq!(branch_of_other_worktree("fatal: invalid reference: x"), None);
+    }
 
     #[test]
     fn a_revision_is_appended_once_keeping_the_list() {

crates/ide-vcs/tests/repo.rs

@@ -1070,7 +1070,7 @@ fn smart_and_force_checkout_with_local_changes_in_the_way() {
     fx.commit_all("other edit");
     fx.git(&["checkout", "-q", "main"]);
     let repo = fx.repo();
-    let opts = |mode| CheckoutOptions { mode, diverged: None };
+    let opts = |mode| CheckoutOptions { mode, ..Default::default() };
 
     // A non-conflicting local edit to a file the switch rewrites.
     fx.write("f.txt", "1\n2\n3\n4\nlocal\n");
@@ -1110,6 +1110,50 @@ fn smart_and_force_checkout_with_local_changes_in_the_way() {
     assert_eq!(fx.read("untouched.txt"), "new\n", "untracked files survive");
 }
 
+#[test]
+fn checkout_of_a_branch_held_by_another_worktree_reports_it_and_changes_nothing() {
+    let fx = Fixture::new();
+    fx.write("f.txt", "1\n");
+    fx.commit_all("base");
+    let linked = fx._tmp.path().join("linked");
+    fx.git(&["worktree", "add", "-q", "-b", "topic", linked.to_str().unwrap()]);
+    let repo = fx.repo();
+    let none = CheckoutOptions::default();
+    let linked_path = std::fs::canonicalize(&linked).unwrap();
+
+    // From the main worktree, the branch the linked worktree has checked out.
+    let outcome = repo.checkout_with("topic", false, &none).unwrap();
+    assert_eq!(outcome, CheckoutOutcome::CheckedOutInWorktree { branch: "topic".into(), path: linked_path.clone() });
+    assert_eq!(repo.branch_info().unwrap().head.as_deref(), Some("main"), "nothing changed");
+
+    // With local changes in the way too: reported before any Smart Checkout stash.
+    fx.write("f.txt", "changed\n");
+    let smart = CheckoutOptions { mode: CheckoutMode::Smart, ..Default::default() };
+    let outcome = repo.checkout_with("topic", false, &smart).unwrap();
+    assert_eq!(outcome, CheckoutOutcome::CheckedOutInWorktree { branch: "topic".into(), path: linked_path.clone() });
+    assert_eq!(fx.read("f.txt"), "changed\n", "local changes untouched");
+    assert!(repo.stashes().unwrap().is_empty());
+    fx.git(&["reset", "-q", "--hard"]);
+
+    // The same refusal from the linked worktree, for the main worktree's branch.
+    let linked_repo = Repo::discover(&linked).unwrap().unwrap();
+    linked_repo.set_execution_allowed(true);
+    let outcome = linked_repo.checkout_with("main", false, &none).unwrap();
+    let main_path = std::fs::canonicalize(&fx.dir).unwrap();
+    assert_eq!(outcome, CheckoutOutcome::CheckedOutInWorktree { branch: "main".into(), path: main_path });
+    assert_eq!(linked_repo.branch_info().unwrap().head.as_deref(), Some("topic"));
+
+    // Overwriting such a branch (New Branch with Checkout) names the worktree, not raw stderr.
+    let error = repo.create_branch_with_overwrite("topic", Some("main"), true, true).unwrap_err();
+    assert!(error.message.contains("branch 'topic' is already checked out in worktree"), "{error}");
+    assert_eq!(repo.branch_info().unwrap().head.as_deref(), Some("main"));
+
+    // Checkout Anyway: both worktrees then have the branch.
+    let anyway = CheckoutOptions { ignore_other_worktrees: true, ..Default::default() };
+    assert_eq!(repo.checkout_with("topic", false, &anyway).unwrap(), CheckoutOutcome::Done);
+    assert_eq!(repo.branch_info().unwrap().head.as_deref(), Some("topic"));
+}
+
 #[test]
 fn checkout_remote_branch_with_existing_local_namesake() {
     let (fx, bare) = with_remote();
@@ -1939,7 +1983,7 @@ fn smart_checkout_keeps_staged_changes_staged() {
     fx.write("f.txt", "1\n2\n3\n4\nlocal\n");
     fx.write("s.txt", "staged\n");
     fx.git(&["add", "s.txt"]);
-    let opts = CheckoutOptions { mode: CheckoutMode::Smart, diverged: None };
+    let opts = CheckoutOptions { mode: CheckoutMode::Smart, ..Default::default() };
     assert_eq!(repo.checkout_with("other", false, &opts).unwrap(), CheckoutOutcome::Done);
     assert_eq!(repo.branch_info().unwrap().head.as_deref(), Some("other"));
     assert_eq!(fx.read("f.txt"), "1\nother\n3\n4\nlocal\n");
@@ -1960,7 +2004,7 @@ fn checkout_reports_untracked_files_it_would_overwrite() {
     fx.write("dir/new.txt", "mine\n");
     let repo = fx.repo();
     for mode in [CheckoutMode::Normal, CheckoutMode::Smart] {
-        let opts = CheckoutOptions { mode, diverged: None };
+        let opts = CheckoutOptions { mode, ..Default::default() };
         let outcome = repo.checkout_with("other", false, &opts).unwrap();
         assert_eq!(outcome, CheckoutOutcome::UntrackedFiles { files: vec!["dir/new.txt".into()] });
         assert_eq!(repo.branch_info().unwrap().head.as_deref(), Some("main"));

crates/ide-workspace/src/process.rs

@@ -246,30 +246,24 @@ mod imp {
     }
 
     pub fn process_start() -> Option<std::time::SystemTime> {
-        #[repr(C)]
-        #[derive(Default)]
-        struct FileTime {
-            low: u32,
-            high: u32,
-        }
         #[link(name = "kernel32")]
         unsafe extern "system" {
+            // The same signature `memory.rs` declares: FILETIMEs read as packed u64s.
             fn GetProcessTimes(
                 process: *mut std::ffi::c_void,
-                creation: *mut FileTime,
-                exit: *mut FileTime,
-                kernel: *mut FileTime,
-                user: *mut FileTime,
+                creation: *mut u64,
+                exit: *mut u64,
+                kernel: *mut u64,
+                user: *mut u64,
             ) -> i32;
         }
         let (mut c, mut e, mut k, mut u) = Default::default();
-        // SAFETY: all out-pointers are valid FILETIME structs.
+        // SAFETY: all out-pointers are valid 64-bit FILETIME slots.
         let ok = unsafe { GetProcessTimes(GetCurrentProcess(), &mut c, &mut e, &mut k, &mut u) };
         if ok == 0 {
             return None;
         }
-        let c: FileTime = c;
-        let ticks = ((c.high as u64) << 32) | c.low as u64; // 100 ns since 1601-01-01
+        let ticks = c; // 100 ns since 1601-01-01
         let unix_100ns = ticks.checked_sub(116_444_736_000_000_000)?;
         Some(std::time::UNIX_EPOCH + std::time::Duration::from_nanos(unix_100ns * 100))
     }