sync: skip clone.bundle when repo.fetchcmd is configured

In Sync_NetworkHalf, clone_bundle defaults to True on initial sync when
self.objdir does not exist yet, and _ApplyCloneBundle is called before
custom_fetch_configured is checked.

For remotes with HTTP/HTTPS URLs that serve /clone.bundle, this causes
repo sync to download and unpack the full clone.bundle into .git/objects
before invoking repo.fetchcmd.

Skip _ApplyCloneBundle when custom_fetch_configured is enabled so
repo.fetchcmd exclusively handles object fetching.

Bug: 543101585
Change-Id: If41a775a75589ad5a23106163f9932e2940b72d2
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/641685
Commit-Queue: Gavin Mak <gavinmak@google.com>
Reviewed-by: Brian Gan <brgan@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>

project.py

@@ -1855,8 +1855,15 @@ class Project:
         else:
             alt_dir = None
 
+        custom_fetch_configured = (
+            self.manifest.manifestProject.use_local_gitdirs
+            and self.manifest.manifestProject.fetch_cmd
+            and not isinstance(self, MetaProject)
+        )
+
         if (
             clone_bundle
+            and not custom_fetch_configured
             and alt_dir is None
             and self._ApplyCloneBundle(
                 initial=is_new, quiet=quiet, verbose=verbose
@@ -1890,12 +1897,6 @@ class Project:
             depth = None
             clone_filter = clone_filter_for_depth
 
-        custom_fetch_configured = (
-            self.manifest.manifestProject.use_local_gitdirs
-            and self.manifest.manifestProject.fetch_cmd
-            and not isinstance(self, MetaProject)
-        )
-
         remote_fetched = False
         if custom_fetch_configured:
             # The custom fetch command is executed unconditionally on every sync

tests/test_project.py

@@ -3453,6 +3453,31 @@ class FetchCmdTests(unittest.TestCase):
             result = fakeproj.Sync(use_local_gitdirs=False)
             self.assertFalse(result)
 
+    def test_sync_network_half_skips_clone_bundle_with_fetch_cmd(self) -> None:
+        """Test Sync_NetworkHalf skips clone.bundle when fetchcmd is set."""
+        with tempfile.TemporaryDirectory() as tempdir:
+            worktree = os.path.join(tempdir, "new-proj")
+            gitdir = os.path.join(worktree, ".git")
+            proj = _create_mock_project(
+                worktree,
+                use_local_gitdirs=True,
+                fetch_cmd="echo hi",
+                gitdir=gitdir,
+                objdir=gitdir,
+            )
+            proj._InitGitDir = mock.MagicMock()
+            proj._InitRemote = mock.MagicMock()
+            proj._InitMRef = mock.MagicMock()
+            proj._CustomFetch = mock.MagicMock(return_value=True)
+            proj._ApplyCloneBundle = mock.MagicMock(return_value=True)
+
+            res = proj.Sync_NetworkHalf(clone_bundle=True, is_new=True)
+
+            self.assertIsNone(res.error)
+            self.assertTrue(res.remote_fetched)
+            proj._ApplyCloneBundle.assert_not_called()
+            proj._CustomFetch.assert_called_once()
+
 
 class ReprojectCmdTests(unittest.TestCase):
     """Tests for the repo.reprojectcmd feature."""