sync: pass --bare option when doing git clone of superproject.v2.12.1

Changed "git pull" to "git fetch" as we are using --bare option. Used the
following command to fetch:
  git fetch origin +refs/heads/*:refs/heads/* --prune

Pass --branch argument to Superproject's UpdateProjectsRevisionId function.

Returned False/None when directories don't exist instead of raise
GitError exception from _Fetch and _LsTree functions. The caller of Fetch
does Clone if Fetch fails.

Tested the code with the following commands.

$ ./run_tests -v

Tested the init and sync code by copying all the repo changes into my Android
AOSP checkout and running repo sync with --use-superproject option.

Bug: https://crbug.com/gerrit/13709
Bug: https://crbug.com/gerrit/13707
Tested-by: Raman Tenneti <rtenneti@google.com>
Change-Id: I3e441ecdfc87c735f46eff0eb98efa63cc2eb22a
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/296222
Reviewed-by: Mike Frysinger <vapier@google.com>

1 files changed, 13 insertions, 6 deletions

diff --git a/subcmds/sync.py b/subcmds/sync.py
index c0f605a8..5855af55 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -271,6 +271,15 @@ later is required to fix a server side protocol bug.
                  dest='repo_upgraded', action='store_true',
                  help=SUPPRESS_HELP)
 
+  def _GetBranch(self):
+    """Returns the branch name for getting the approved manifest."""
+    p = self.manifest.manifestProject
+    b = p.GetBranch(p.CurrentBranch)
+    branch = b.merge
+    if branch.startswith(R_HEADS):
+      branch = branch[len(R_HEADS):]
+    return branch
+
   def _UpdateProjectsRevisionId(self, opt, args):
     """Update revisionId of every project with the SHA from superproject.
 
@@ -302,9 +311,11 @@ later is required to fix a server side protocol bug.
     all_projects = self.GetProjects(args,
                                     missing_ok=True,
                                     submodules_ok=opt.fetch_submodules)
+    branch = self._GetBranch()
     manifest_path = superproject.UpdateProjectsRevisionId(self.manifest,
                                                           all_projects,
-                                                          url=superproject_url)
+                                                          url=superproject_url,
+                                                          branch=branch)
     if not manifest_path:
       print('error: Update of revsionId from superproject has failed',
             file=sys.stderr)
@@ -753,11 +764,7 @@ later is required to fix a server side protocol bug.
     try:
       server = xmlrpc.client.Server(manifest_server, transport=transport)
       if opt.smart_sync:
-        p = self.manifest.manifestProject
-        b = p.GetBranch(p.CurrentBranch)
-        branch = b.merge
-        if branch.startswith(R_HEADS):
-          branch = branch[len(R_HEADS):]
+        branch = self._GetBranch()
 
         if 'SYNC_TARGET' in os.environ:
           target = os.environ['SYNC_TARGET']