Sync: Add option to prune refs during sync

By passing --prune to the sync command, the --prune option is
given to the `git fetch`, causing refs that no longer exist on
the remote to be removed.

Change-Id: I3cedacce14276d96ac2d5aabf2d07fd05e92bc02

project.py

@@ -1110,7 +1110,8 @@ class Project(object):
       clone_bundle=True,
       no_tags=False,
       archive=False,
-      optimized_fetch=False):
+      optimized_fetch=False,
+      prune=False):
     """Perform only the network IO portion of the sync process.
        Local working directory/branch state is not affected.
     """
@@ -1181,7 +1182,7 @@ class Project(object):
     if (need_to_fetch
         and not self._RemoteFetch(initial=is_new, quiet=quiet, alt_dir=alt_dir,
                                   current_branch_only=current_branch_only,
-                                  no_tags=no_tags)):
+                                  no_tags=no_tags, prune=prune)):
       return False
 
     if self.worktree:
@@ -1795,7 +1796,8 @@ class Project(object):
                    initial=False,
                    quiet=False,
                    alt_dir=None,
-                   no_tags=False):
+                   no_tags=False,
+                   prune=False):
 
     is_sha1 = False
     tag_name = None
@@ -1908,6 +1910,9 @@ class Project(object):
     else:
       cmd.append('--tags')
 
+    if prune:
+      cmd.append('--prune')
+
     spec = []
     if not current_branch_only:
       # Fetch whole repo

subcmds/sync.py

@@ -151,6 +151,9 @@ The --optimized-fetch option can be used to only fetch projects that
 are fixed to a sha1 revision if the sha1 revision does not already
 exist locally.
 
+The --prune option can be used to remove any refs that no longer
+exist on the remote.
+
 SSH Connections
 ---------------
 
@@ -234,6 +237,8 @@ later is required to fix a server side protocol bug.
     p.add_option('--optimized-fetch',
                  dest='optimized_fetch', action='store_true',
                  help='only fetch projects fixed to sha1 if revision does not exist locally')
+    p.add_option('--prune', dest='prune', action='store_true',
+                 help='delete refs that no longer exist on the remote')
     if show_smart:
       p.add_option('-s', '--smart-sync',
                    dest='smart_sync', action='store_true',
@@ -305,7 +310,8 @@ later is required to fix a server side protocol bug.
           force_sync=opt.force_sync,
           clone_bundle=not opt.no_clone_bundle,
           no_tags=opt.no_tags, archive=self.manifest.IsArchive,
-          optimized_fetch=opt.optimized_fetch)
+          optimized_fetch=opt.optimized_fetch,
+          prune=opt.prune)
         self._fetch_times.Set(project, time.time() - start)
 
         # Lock around all the rest of the code, since printing, updating a set