test: add regression coverage for reftable active_branch

Copilot · Byron · Copilot · commit 057fc47c9100 · 2026-03-20T22:19:45.000Z
Co-authored-by: Byron <63622+Byron@users.noreply.github.com> Agent-Logs-Url: https://github.com/gitpython-developers/GitPython/sessions/cb73f600-a42a-4400-b68c-da530d57677f
diff --git a/git/repo/base.py b/git/repo/base.py
@@ -1046,9 +1046,9 @@ def active_branch(self) -> Head:
             :class:`~git.refs.head.Head` to the active branch
         """
         try:
-            return Head(self, self.git.symbolic_ref("HEAD").strip())
+            return Head(self, self.git.symbolic_ref("-q", "HEAD").strip())
         except GitCommandError as err:
-            if err.status == 1 or "not a symbolic ref" in str(err).lower():
+            if err.status == 1:
                 raise TypeError("HEAD is a detached symbolic reference as it points to a commit") from err
             raise
 
diff --git a/test/test_repo.py b/test/test_repo.py
@@ -973,9 +973,22 @@ def test_empty_repo_reftable_active_branch(self, rw_dir):
             raise
 
         repo = Repo(rw_dir)
-        self.assertEqual(repo.active_branch.name, "master")
+        expected_active_branch_path = git.symbolic_ref("HEAD").strip()
+        expected_active_branch_name = git.symbolic_ref("--short", "HEAD").strip()
+        self.assertEqual(repo.active_branch.path, expected_active_branch_path)
+        self.assertEqual(repo.active_branch.name, expected_active_branch_name)
         assert not repo.active_branch.is_valid(), "Branch is yet to be born"
 
+    @with_rw_directory
+    def test_active_branch_raises_type_error_when_head_is_detached(self, rw_dir):
+        repo = Repo.init(rw_dir)
+        with open(osp.join(rw_dir, "a.txt"), "w") as f:
+            f.write("a")
+        repo.index.add(["a.txt"])
+        repo.index.commit("initial commit")
+        repo.git.checkout(repo.head.commit.hexsha)
+        self.assertRaisesRegex(TypeError, "detached symbolic reference", lambda: repo.active_branch)
+
     def test_merge_base(self):
         repo = self.rorepo
         c1 = "f6aa8d1"
