fix: handle linked worktree correctly

src/pathname.rs

@@ -44,7 +44,9 @@ pub fn normalize_paths(
     repo: &Repository,
     paths: Vec<String>,
 ) -> Result<Vec<String>, NormalizePathError> {
-    let repo_root = repo.path().parent().unwrap();
+    let repo_root = repo.workdir().ok_or(NormalizePathError::RuntimeError(
+        "repository has no working directory",
+    ))?;
     let mut workdir_paths = Vec::new();
     for path in paths {
         let path = Path::new(&path);

tests/dah.rs

@@ -197,6 +197,39 @@ fn git_dah_step_stages_only_one_action() {
     assert!(!status.contains(Status::WT_MODIFIED));
 }
 
+#[test]
+fn git_dah_runs_from_linked_worktree() {
+    let fixture = DahFixture::new();
+    let linked_root = fixture.worktree_root.parent().unwrap().join("linked");
+    git_command(
+        &fixture.worktree_repo(),
+        &[
+            "worktree",
+            "add",
+            "-b",
+            "linked",
+            linked_root.to_str().unwrap(),
+        ],
+    );
+    fs::write(linked_root.join("tracked.txt"), "linked\n").unwrap();
+
+    let output = Command::new(git_dah_exe())
+        .current_dir(&linked_root)
+        .env("GIT_EDITOR", &fixture.editor_path)
+        .env("GIT_DAH_TEST_MESSAGE", "Linked worktree")
+        .args(["--step", "--no-fetch"])
+        .output()
+        .expect("spawn git-dah");
+
+    assert_success(&output);
+
+    let repo = Repository::open(linked_root).unwrap();
+    assert_eq!("linked", current_branch(&repo));
+    let status = repo.status_file(Path::new("tracked.txt")).unwrap();
+    assert!(status.contains(Status::INDEX_MODIFIED));
+    assert!(!status.contains(Status::WT_MODIFIED));
+}
+
 #[test]
 fn git_dah_renames_default_branch_commits_and_pushes() {
     let fixture = DahFixture::new();

tests/stale.rs

@@ -15,7 +15,7 @@ use url::Url;
 
 use bin::git_stale_exe;
 use git_worktree::{
-    git_add_remote, git_checkout_branch, git_commit_at, git_init_with_initial_commit,
+    git_add_remote, git_checkout_branch, git_command, git_commit_at, git_init_with_initial_commit,
     git_set_config, local_branch_exists, ref_exists,
 };
 
@@ -221,6 +221,37 @@ fn git_stale_without_since_lists_only_local_branches_without_upstream() {
     );
 }
 
+#[test]
+fn git_stale_lists_branches_from_linked_worktree() {
+    let fixture = StaleFixture::new();
+    let linked_root = fixture.worktree_root.parent().unwrap().join("linked");
+    git_command(
+        &fixture.worktree_repo(),
+        &[
+            "worktree",
+            "add",
+            "-b",
+            "linked",
+            linked_root.to_str().unwrap(),
+        ],
+    );
+
+    let output = Command::new(git_stale_exe())
+        .current_dir(linked_root)
+        .output()
+        .expect("spawn git-stale");
+
+    assert!(
+        output.status.success(),
+        "git-stale failed: stderr={}",
+        stderr_text(&output)
+    );
+    assert_eq!(
+        vec!["refs/heads/topic/local-only".to_owned()],
+        sorted_stdout_lines(&output)
+    );
+}
+
 #[test]
 fn git_stale_since_lists_only_stale_unprotected_local_branches() {
     let fixture = StaleFixture::new();

tests/whose.rs

@@ -49,6 +49,49 @@ fn git_whose_prints_owners_for_indexed_paths() {
     );
 }
 
+#[test]
+fn git_whose_prints_owners_from_linked_worktree() {
+    let tmpdir = TempDir::new().unwrap();
+    let root = tmpdir.path().join("main");
+    let linked = tmpdir.path().join("linked");
+
+    let repo = git_init(&root);
+    git_set_config(&repo, "user.name", "t");
+    git_set_config(&repo, "user.email", "t@example.com");
+
+    let co_path = root.join(".github/CODEOWNERS");
+    mkdir_p(co_path.parent().unwrap());
+    write(co_path, b"*.rs @rust-team\n");
+
+    let src = root.join("src/lib.rs");
+    mkdir_p(src.parent().unwrap());
+    write(&src, b"fn f() {}\n");
+
+    git_add(&repo, ".github/CODEOWNERS");
+    git_add(&repo, "src/lib.rs");
+    git_command(&repo, &["commit", "-m", "init"]);
+    git_command(
+        &repo,
+        &["worktree", "add", "-b", "linked", linked.to_str().unwrap()],
+    );
+
+    let exe = git_whose_exe();
+    let out = Command::new(exe)
+        .current_dir(linked)
+        .args(["src/lib.rs"])
+        .output()
+        .expect("spawn git-whose");
+
+    assert!(
+        out.status.success(),
+        "git-whose failed: stderr={}",
+        String::from_utf8_lossy(&out.stderr)
+    );
+
+    let stdout = String::from_utf8_lossy(&out.stdout);
+    assert_eq!(stdout, "src/lib.rs: @rust-team\n");
+}
+
 #[test]
 fn git_whose_prints_owners_for_bare_repo_head_tree() {
     let tmpdir = TempDir::new().unwrap();