[PATCH v2 1/4] libgit: Add a read-only helper to test the worktree lock

[Peter Jones <pjones@xxxxxxxxxx>]

Add the function is_worktree_locked(), which is a helper to tell if a
worktree is locked without having to be able to modify it.

Signed-off-by: Peter Jones <pjones@xxxxxxxxxx>
---
 builtin/worktree.c |  2 +-
 worktree.c         | 16 ++++++++++++++++
 worktree.h         |  5 +++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 4de44f579af..86305cc1fe1 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -245,7 +245,7 @@ static void validate_worktree_add(const char *path, const struct add_opts *opts)
 	if (!wt)
 		goto done;
 
-	locked = !!worktree_lock_reason(wt);
+	locked = is_worktree_locked(wt);
 	if ((!locked && opts->force) || (locked && opts->force > 1)) {
 		if (delete_git_dir(wt->id))
 		    die(_("unable to re-add worktree '%s'"), path);
diff --git a/worktree.c b/worktree.c
index 5b4793caa34..4924805c389 100644
--- a/worktree.c
+++ b/worktree.c
@@ -244,6 +244,22 @@ int is_main_worktree(const struct worktree *wt)
 	return !wt->id;
 }
 
+int is_worktree_locked(const struct worktree *wt)
+{
+	struct strbuf path = STRBUF_INIT;
+	int locked = 0;
+
+	if (wt->lock_reason_valid && wt->lock_reason)
+		return 1;
+
+	strbuf_addstr(&path, worktree_git_path(wt, "locked"));
+	if (file_exists(path.buf))
+		locked = 1;
+
+	strbuf_release(&path);
+	return locked;
+}
+
 const char *worktree_lock_reason(struct worktree *wt)
 {
 	assert(!is_main_worktree(wt));
diff --git a/worktree.h b/worktree.h
index caecc7a281c..5ff16c414b5 100644
--- a/worktree.h
+++ b/worktree.h
@@ -56,6 +56,11 @@ struct worktree *find_worktree(struct worktree **list,
  */
 int is_main_worktree(const struct worktree *wt);
 
+/*
+ * Return true if the given worktree is locked
+ */
+int is_worktree_locked(const struct worktree *wt);
+
 /*
  * Return the reason string if the given worktree is locked or NULL
  * otherwise.
-- 
2.23.0