Make rebasing working with worktrees + other local checkouts

src/stack_pr/cli.py

@@ -64,6 +64,7 @@
 from subprocess import SubprocessError
 
 from stack_pr.git import (
+    branch_checked_out_in_other_worktree,
     branch_exists,
     check_gh_installed,
     get_current_branch_name,
@@ -1261,6 +1262,7 @@ def command_land(args: CommonArgs) -> None:
     log(h("LAND"), level=1)
 
     current_branch = get_current_branch_name()
+    stack_base = args.base
 
     if should_update_local_base(
         head=args.head,
@@ -1269,13 +1271,32 @@ def command_land(args: CommonArgs) -> None:
         target=args.target,
         verbose=args.verbose,
     ):
-        update_local_base(
-            base=args.base, remote=args.remote, target=args.target, verbose=args.verbose
+        base_worktree = (
+            branch_checked_out_in_other_worktree(args.base)
+            if branch_exists(args.base)
+            else None
         )
-        run_shell_command(["git", "checkout", current_branch], quiet=not args.verbose)
+        if base_worktree is None:
+            update_local_base(
+                base=args.base,
+                remote=args.remote,
+                target=args.target,
+                verbose=args.verbose,
+            )
+            run_shell_command(["git", "checkout", current_branch], quiet=not args.verbose)
+        else:
+            stack_base = f"{args.remote}/{args.target}"
+            log(
+                h(
+                    f"Skipping update of local branch {args.base}: checked out in"
+                    f" worktree at {base_worktree}. Using {stack_base} as stack"
+                    " base."
+                ),
+                level=1,
+            )
 
     # Determine what commits belong to the stack
-    st = get_stack(base=args.base, head=args.head, verbose=args.verbose)
+    st = get_stack(base=stack_base, head=args.head, verbose=args.verbose)
     if not st:
         log(h("Empty stack!"), level=1)
         log(h(blue("SUCCESS!")), level=1)
@@ -1313,10 +1334,20 @@ def command_land(args: CommonArgs) -> None:
 
     # If local branch {target} exists, rebase it on the remote/target
     if branch_exists(args.target):
-        run_shell_command(
-            ["git", "rebase", f"{args.remote}/{args.target}", args.target],
-            quiet=not args.verbose,
-        )
+        target_worktree = branch_checked_out_in_other_worktree(args.target)
+        if target_worktree is None:
+            run_shell_command(
+                ["git", "rebase", f"{args.remote}/{args.target}", args.target],
+                quiet=not args.verbose,
+            )
+        else:
+            log(
+                h(
+                    f"Skipping update of local branch {args.target}: checked out in"
+                    f" worktree at {target_worktree}."
+                ),
+                level=1,
+            )
     run_shell_command(
         ["git", "rebase", f"{args.remote}/{args.target}", current_branch],
         quiet=not args.verbose,

src/stack_pr/git.py

@@ -76,6 +76,36 @@ def branch_exists(branch: str, repo_dir: Path | None = None) -> bool:
     raise GitError("Not inside a valid git repository.")
 
 
+def branch_checked_out_in_other_worktree(
+    branch: str, repo_dir: Path | None = None
+) -> Path | None:
+    """Return the worktree path if the branch is checked out elsewhere."""
+    try:
+        worktree_info = get_command_output(
+            ["git", "worktree", "list", "--porcelain"], cwd=repo_dir
+        )
+    except subprocess.CalledProcessError as e:
+        if e.returncode == GIT_NOT_A_REPO_ERROR:
+            raise GitError("Not inside a valid git repository.") from e
+        raise
+
+    current_root = get_repo_root(repo_dir).resolve()
+    current_worktree: Path | None = None
+
+    for line in worktree_info.splitlines():
+        if line.startswith("worktree "):
+            current_worktree = Path(line.removeprefix("worktree ")).resolve()
+            continue
+        if not line.startswith("branch refs/heads/") or current_worktree is None:
+            continue
+        if line.removeprefix("branch refs/heads/") != branch:
+            continue
+        if current_worktree != current_root:
+            return current_worktree
+
+    return None
+
+
 def get_current_branch_name(repo_dir: Path | None = None) -> str:
     """Returns the name of the branch currently checked out.
 

tests/test_land.py

@@ -0,0 +1,99 @@
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+from stack_pr.cli import CommonArgs, command_land
+
+
+def test_command_land_skips_target_rebase_checked_out_in_other_worktree(
+    monkeypatch,
+) -> None:
+    commands: list[list[str]] = []
+    logs: list[str] = []
+
+    monkeypatch.setattr("stack_pr.cli.get_current_branch_name", lambda: "feature")
+    monkeypatch.setattr(
+        "stack_pr.cli.should_update_local_base",
+        lambda **_: False,
+    )
+    monkeypatch.setattr("stack_pr.cli.get_stack", lambda **_: [object()])
+    monkeypatch.setattr("stack_pr.cli.set_base_branches", lambda *_, **__: None)
+    monkeypatch.setattr("stack_pr.cli.print_stack", lambda *_, **__: None)
+    monkeypatch.setattr("stack_pr.cli.verify", lambda *_, **__: None)
+    monkeypatch.setattr("stack_pr.cli.land_pr", lambda *_, **__: None)
+    monkeypatch.setattr("stack_pr.cli.delete_local_branches", lambda *_, **__: None)
+    monkeypatch.setattr("stack_pr.cli.branch_exists", lambda _: True)
+    monkeypatch.setattr(
+        "stack_pr.cli.branch_checked_out_in_other_worktree",
+        lambda branch: Path("/tmp/other-worktree") if branch == "main" else None,
+    )
+    monkeypatch.setattr(
+        "stack_pr.cli.run_shell_command",
+        lambda cmd, quiet=True: commands.append(cmd),
+    )
+    monkeypatch.setattr("stack_pr.cli.log", lambda msg, level=1: logs.append(msg))
+
+    command_land(
+        CommonArgs(
+            base="main",
+            head="feature",
+            remote="origin",
+            target="main",
+            hyperlinks=False,
+            verbose=False,
+            branch_name_template="$USERNAME/stack/$ID",
+            show_tips=True,
+            land_disabled=False,
+        )
+    )
+
+    assert ["git", "rebase", "origin/main", "main"] not in commands
+    assert ["git", "rebase", "origin/main", "feature"] in commands
+    assert any("Skipping update of local branch main" in msg for msg in logs)
+
+
+def test_command_land_uses_remote_target_when_base_checked_out_in_other_worktree(
+    monkeypatch,
+) -> None:
+    stack_bases: list[str] = []
+    logs: list[str] = []
+    updated_bases: list[str] = []
+
+    monkeypatch.setattr("stack_pr.cli.get_current_branch_name", lambda: "feature")
+    monkeypatch.setattr(
+        "stack_pr.cli.should_update_local_base",
+        lambda **_: True,
+    )
+    monkeypatch.setattr("stack_pr.cli.branch_exists", lambda branch: branch == "main")
+    monkeypatch.setattr(
+        "stack_pr.cli.branch_checked_out_in_other_worktree",
+        lambda branch: Path("/tmp/other-worktree") if branch == "main" else None,
+    )
+    monkeypatch.setattr(
+        "stack_pr.cli.update_local_base",
+        lambda *, base, remote, target, verbose: updated_bases.append(base),
+    )
+    monkeypatch.setattr(
+        "stack_pr.cli.get_stack",
+        lambda *, base, head, verbose: stack_bases.append(base) or [],
+    )
+    monkeypatch.setattr("stack_pr.cli.log", lambda msg, level=1: logs.append(msg))
+
+    command_land(
+        CommonArgs(
+            base="main",
+            head="feature",
+            remote="origin",
+            target="main",
+            hyperlinks=False,
+            verbose=False,
+            branch_name_template="$USERNAME/stack/$ID",
+            show_tips=True,
+            land_disabled=False,
+        )
+    )
+
+    assert updated_bases == []
+    assert stack_bases == ["origin/main"]
+    assert any("Using origin/main as stack base." in msg for msg in logs)