diff --git a/tests/basic/test_repo.py b/tests/basic/test_repo.py
index 9633ec208..5d1ff335b 100644
--- a/tests/basic/test_repo.py
+++ b/tests/basic/test_repo.py
@@ -420,6 +420,121 @@ class TestRepo(unittest.TestCase):
             self.assertEqual(commit.author.name, "Test User (aider)") # Should be modified (default True)
             self.assertEqual(commit.committer.name, "Test User (aider)") # Should be modified (default True)
 
+    def test_commit_ai_edits_no_coauthor_explicit_false(self):
+        # Test AI edits (aider_edits=True) when co-authored-by is False,
+        # but author or committer attribution is explicitly disabled.
+        if platform.system() == "Windows":
+            return
+
+        with GitTemporaryDirectory():
+            # Setup repo
+            raw_repo = git.Repo()
+            raw_repo.config_writer().set_value("user", "name", "Test User").release()
+            raw_repo.config_writer().set_value("user", "email", "test@example.com").release()
+            fname = Path("file.txt")
+            fname.touch()
+            raw_repo.git.add(str(fname))
+            raw_repo.git.commit("-m", "initial commit")
+
+            io = InputOutput()
+
+            # Case 1: attribute_author = False, attribute_committer = None (default True)
+            mock_coder_no_author = MagicMock()
+            mock_coder_no_author.args.attribute_co_authored_by = False
+            mock_coder_no_author.args.attribute_author = False # Explicit False
+            mock_coder_no_author.args.attribute_committer = None # Default True
+            mock_coder_no_author.args.attribute_commit_message_author = False
+            mock_coder_no_author.args.attribute_commit_message_committer = False
+            mock_coder_no_author.main_model = MagicMock()
+            mock_coder_no_author.main_model.name = "gpt-test-no-author"
+
+            git_repo_no_author = GitRepo(io, None, None)
+            fname.write_text("no author content")
+            commit_result = git_repo_no_author.commit(fnames=[str(fname)], aider_edits=True, coder=mock_coder_no_author, message="Aider no author")
+            self.assertIsNotNone(commit_result)
+            commit = raw_repo.head.commit
+            self.assertNotIn("Co-authored-by:", commit.message)
+            self.assertEqual(commit.author.name, "Test User") # Explicit False
+            self.assertEqual(commit.committer.name, "Test User (aider)") # Default True
+
+            # Case 2: attribute_author = None (default True), attribute_committer = False
+            mock_coder_no_committer = MagicMock()
+            mock_coder_no_committer.args.attribute_co_authored_by = False
+            mock_coder_no_committer.args.attribute_author = None # Default True
+            mock_coder_no_committer.args.attribute_committer = False # Explicit False
+            mock_coder_no_committer.args.attribute_commit_message_author = False
+            mock_coder_no_committer.args.attribute_commit_message_committer = False
+            mock_coder_no_committer.main_model = MagicMock()
+            mock_coder_no_committer.main_model.name = "gpt-test-no-committer"
+
+            git_repo_no_committer = GitRepo(io, None, None)
+            fname.write_text("no committer content")
+            commit_result = git_repo_no_committer.commit(fnames=[str(fname)], aider_edits=True, coder=mock_coder_no_committer, message="Aider no committer")
+            self.assertIsNotNone(commit_result)
+            commit = raw_repo.head.commit
+            self.assertNotIn("Co-authored-by:", commit.message)
+            self.assertEqual(commit.author.name, "Test User (aider)") # Default True
+            self.assertEqual(commit.committer.name, "Test User") # Explicit False
+
+
+    def test_commit_user_edits_ignores_co_author(self):
+        # Test user edits (aider_edits=False) behavior regarding co-author and name attribution.
+        # Co-author should be ignored, Author never modified, Committer follows flag.
+        if platform.system() == "Windows":
+            return
+
+        with GitTemporaryDirectory():
+            # Setup repo
+            raw_repo = git.Repo()
+            raw_repo.config_writer().set_value("user", "name", "Test User").release()
+            raw_repo.config_writer().set_value("user", "email", "test@example.com").release()
+            fname = Path("file.txt")
+            fname.touch()
+            raw_repo.git.add(str(fname))
+            raw_repo.git.commit("-m", "initial commit")
+
+            io = InputOutput()
+
+            # Case 1: co_author=True, committer=None (default True)
+            mock_coder_user_default = MagicMock()
+            mock_coder_user_default.args.attribute_co_authored_by = True # Should be ignored
+            mock_coder_user_default.args.attribute_author = True # Should be ignored
+            mock_coder_user_default.args.attribute_committer = None # Default True
+            mock_coder_user_default.args.attribute_commit_message_author = False
+            mock_coder_user_default.args.attribute_commit_message_committer = False
+            mock_coder_user_default.main_model = MagicMock()
+            mock_coder_user_default.main_model.name = "gpt-user-default"
+
+            git_repo_user_default = GitRepo(io, None, None)
+            fname.write_text("user default content")
+            commit_result = git_repo_user_default.commit(fnames=[str(fname)], aider_edits=False, coder=mock_coder_user_default, message="User default")
+            self.assertIsNotNone(commit_result)
+            commit = raw_repo.head.commit
+            self.assertNotIn("Co-authored-by:", commit.message) # Ignored
+            self.assertEqual(commit.author.name, "Test User") # Never modified
+            self.assertEqual(commit.committer.name, "Test User (aider)") # Default True
+
+            # Case 2: co_author=True, committer=False
+            mock_coder_user_no_committer = MagicMock()
+            mock_coder_user_no_committer.args.attribute_co_authored_by = True # Should be ignored
+            mock_coder_user_no_committer.args.attribute_author = True # Should be ignored
+            mock_coder_user_no_committer.args.attribute_committer = False # Explicit False
+            mock_coder_user_no_committer.args.attribute_commit_message_author = False
+            mock_coder_user_no_committer.args.attribute_commit_message_committer = False
+            mock_coder_user_no_committer.main_model = MagicMock()
+            mock_coder_user_no_committer.main_model.name = "gpt-user-no-committer"
+
+            # Need to init GitRepo with attribute_committer=False for this case
+            git_repo_user_no_committer = GitRepo(io, None, None, attribute_committer=False)
+            fname.write_text("user no committer content")
+            # Pass coder to simulate args being present, though GitRepo init matters more here
+            commit_result = git_repo_user_no_committer.commit(fnames=[str(fname)], aider_edits=False, coder=mock_coder_user_no_committer, message="User no committer")
+            self.assertIsNotNone(commit_result)
+            commit = raw_repo.head.commit
+            self.assertNotIn("Co-authored-by:", commit.message) # Ignored
+            self.assertEqual(commit.author.name, "Test User") # Never modified
+            self.assertEqual(commit.committer.name, "Test User") # Explicit False
+
 
     def test_get_tracked_files(self):
         # Create a temporary directory