fix(agents): delete agent tasks whose worktree git no longer recognizes (#979)

Deleting a worktree-isolated agent task together with its worktree failed for good with "fatal: '<path>' is not a working tree" once git no longer recognized the worktree: its registration was pruned, the repository moved, or the worktree's `.git` file was deleted.

When `git worktree remove --force` fails but the folder is still there and lies inside the agent worktrees directory, the folder is now removed directly, so the task can always be deleted. A stale registration is pruned by git later. Paths outside that directory (the task's cwd comes from its stored record) keep git's error and are never deleted by hand.

Fixes #969.

Co-authored-by: a-rookie-of-C-language <[email protected]>

crates/ide-agent/src/lib.rs

@@ -823,7 +823,8 @@ impl AgentManager {
         // A copy of the task (a fork) may work in the same worktree.
         let shared = self.tasks.read().values().any(|t| t.id != id && t.state.lock().task.cwd.0 == cwd);
         if remove_worktree && !shared && isolation == Isolation::Worktree && cwd.exists() {
-            blocking(move || worktree::remove(&root, &cwd)).await?;
+            let worktrees = self.shared.paths.worktrees_dir.clone();
+            blocking(move || worktree::remove(&root, &worktrees, &cwd)).await?;
         }
         self.tasks.write().remove(id);
         *task.deleted.lock() = true;

crates/ide-agent/src/worktree.rs

@@ -48,8 +48,24 @@ pub(crate) fn create(project_root: &Path, worktrees_dir: &Path, title: &str, bas
     Ok(Created { path, branch, base, base_commit })
 }
 
-pub(crate) fn remove(project_root: &Path, path: &Path) -> IdeResult<()> {
-    repo_at(project_root)?.remove_worktree(path, true)
+/// `git worktree remove --force -- <path>`. When git no longer recognizes the
+/// worktree (a pruned registration, a moved repository, a deleted `.git` file)
+/// it fails with "is not a working tree". A folder under `worktrees_dir` is still
+/// ours, so it is removed directly to keep the task deletable (a stale
+/// registration prunes later); anything else keeps git's error.
+pub(crate) fn remove(project_root: &Path, worktrees_dir: &Path, path: &Path) -> IdeResult<()> {
+    let repo = repo_at(project_root)?;
+    let err = match repo.remove_worktree(path, true) {
+        Ok(()) => return Ok(()),
+        Err(e) => e,
+    };
+    if !path.exists() {
+        return Ok(());
+    }
+    if !path.starts_with(worktrees_dir) || path == worktrees_dir {
+        return Err(err);
+    }
+    std::fs::remove_dir_all(path).map_err(|e| IdeError::internal(e.to_string()))
 }
 
 /// Files under `cwd` that differ from `base` (untracked files included), with line counts.
@@ -153,7 +169,7 @@ mod tests {
         assert!(snapshot(&dir).unwrap().is_empty());
         assert_eq!(file_at(&dir, &dir.join("a.txt"), "HEAD").unwrap(), None);
         assert!(create(&dir, &tmp.path().join("wt"), "Edit A", None).is_err());
-        assert!(remove(&dir, &dir).is_err());
+        assert!(remove(&dir, tmp.path(), &dir).is_err());
     }
 
     fn git(dir: &Path, args: &[&str]) {
@@ -202,7 +218,38 @@ mod tests {
 
         // A second task with the same title gets its own worktree.
         assert_eq!(create(&repo, &tmp.path().join("wt"), "Edit A", None).unwrap().branch, "agent/edit-a-2");
-        remove(&repo, &created.path).unwrap();
+        remove(&repo, &tmp.path().join("wt"), &created.path).unwrap();
         assert!(!created.path.exists());
     }
+
+    #[test]
+    fn a_broken_worktree_registration_still_leaves_a_deletable_folder() {
+        let tmp = tempfile::tempdir().unwrap();
+        let repo = tmp.path().join("repo");
+        std::fs::create_dir(&repo).unwrap();
+        git(&repo, &["init", "-q", "-b", "main"]);
+        std::fs::write(repo.join("a.txt"), "one\n").unwrap();
+        git(&repo, &["add", "."]);
+        git(&repo, &["commit", "-q", "-m", "init"]);
+
+        // A pruned registration (the repository moved, `git worktree prune` ran).
+        let created = create(&repo, &tmp.path().join("wt"), "Edit A", None).unwrap();
+        let registration = repo.join(".git/worktrees").join(created.path.file_name().unwrap());
+        std::fs::remove_dir_all(registration).unwrap();
+        remove(&repo, &tmp.path().join("wt"), &created.path).unwrap();
+        assert!(!created.path.exists());
+
+        // A deleted `.git` file in the worktree itself.
+        let created = create(&repo, &tmp.path().join("wt"), "Edit B", None).unwrap();
+        std::fs::remove_file(created.path.join(".git")).unwrap();
+        remove(&repo, &tmp.path().join("wt"), &created.path).unwrap();
+        assert!(!created.path.exists());
+
+        // A folder outside the worktrees directory is never deleted by hand.
+        let elsewhere = tmp.path().join("elsewhere");
+        std::fs::create_dir(&elsewhere).unwrap();
+        std::fs::write(elsewhere.join("keep.txt"), "x\n").unwrap();
+        assert!(remove(&repo, &tmp.path().join("wt"), &elsewhere).is_err());
+        assert!(elsewhere.join("keep.txt").exists());
+    }
 }