project: don't rerun git status after a failed snapshot

When a status snapshot fails, fall back directly to _IsDirtyLegacy()
instead of IsDirty() to avoid running git status twice.

Expose Project.GetDirtyAndHead() so sync bloat checks can inspect
worktree state without invoking private Project methods.

Bug: 565047698
Change-Id: I6432ed82da88778eec9d151fd5b70bedb1efc62b
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/634424
Reviewed-by: Brian Gan <brgan@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>

1 files changed, 2 insertions, 13 deletions

diff --git a/subcmds/sync.py b/subcmds/sync.py
index d60a256b4..bae367781 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -1614,20 +1614,9 @@ later is required to fix a server side protocol bug.
         # Only check dirty or locally modified projects. These can't be
         # freshly cloned and will accumulate garbage.
         try:
-            status = project._GetStatusSnapshot(
-                untracked_files="normal", branch=True
-            )
-            if status is not None:
-                is_dirty = status.is_dirty(consider_untracked=True)
-                head_rev = status.branch_oid
-            else:
-                is_dirty = project.IsDirty(consider_untracked=True)
-                head_rev = project.work_git.rev_parse(HEAD)
-
+            is_dirty, head_rev = project.GetDirtyAndHead()
             if head_rev is None:
-                # Porcelain v2 reports an unborn branch as "(initial)".  The
-                # legacy rev-parse path failed here and skipped the bloat
-                # calculation, so preserve that behavior.
+                # An unborn branch has no HEAD to compare, so skip it.
                 return None
 
             manifest_rev = project.GetRevisionId(project.bare_ref.all)