Add 'repo sync -l' to only do local operations

This permits usage of 'repo sync' while offline, as we bypass the
network based portions of the code and do only the local sync.

An example use case might be:

  repo sync -n  ; # while we have network
  ... some time later ...
  repo sync -l  ; # while without network, come up to date

Signed-off-by: Shawn O. Pearce <sop@google.com>

subcmds/sync.py

@@ -52,6 +52,9 @@ revision is temporarily needed.
 """
 
   def _Options(self, p):
+    p.add_option('-l','--local-only',
+                 dest='local_only', action='store_true',
+                 help="only update working tree, don't fetch")
     p.add_option('-n','--network-only',
                  dest='network_only', action='store_true',
                  help="fetch only, don't update working tree")
@@ -80,6 +83,9 @@ revision is temporarily needed.
     if opt.network_only and opt.detach_head:
       print >>sys.stderr, 'error: cannot combine -n and -d'
       sys.exit(1)
+    if opt.network_only and opt.local_only:
+      print >>sys.stderr, 'error: cannot combine -n and -l'
+      sys.exit(1)
 
     rp = self.manifest.repoProject
     rp.PreSync()
@@ -93,34 +99,36 @@ revision is temporarily needed.
           project.PostRepoUpgrade()
 
     all = self.GetProjects(args, missing_ok=True)
-    fetched = self._Fetch(rp, mp, *all)
 
-    if rp.HasChanges:
-      print >>sys.stderr, 'info: A new version of repo is available'
-      print >>sys.stderr, ''
-      if opt.no_repo_verify or _VerifyTag(rp):
-        if not rp.Sync_LocalHalf():
+    if not opt.local_only:
+      fetched = self._Fetch(rp, mp, *all)
+
+      if rp.HasChanges:
+        print >>sys.stderr, 'info: A new version of repo is available'
+        print >>sys.stderr, ''
+        if opt.no_repo_verify or _VerifyTag(rp):
+          if not rp.Sync_LocalHalf():
+            sys.exit(1)
+          print >>sys.stderr, 'info: Restarting repo with latest version'
+          raise RepoChangedException(['--repo-upgraded'])
+        else:
+          print >>sys.stderr, 'warning: Skipped upgrade to unverified version'
+
+      if opt.network_only:
+        # bail out now; the rest touches the working tree
+        return
+
+      if mp.HasChanges:
+        if not mp.Sync_LocalHalf():
           sys.exit(1)
-        print >>sys.stderr, 'info: Restarting repo with latest version'
-        raise RepoChangedException(['--repo-upgraded'])
-      else:
-        print >>sys.stderr, 'warning: Skipped upgrade to unverified version'
-
-    if opt.network_only:
-      # bail out now; the rest touches the working tree
-      return
-
-    if mp.HasChanges:
-      if not mp.Sync_LocalHalf():
-        sys.exit(1)
 
-      self.manifest._Unload()
-      all = self.GetProjects(args, missing_ok=True)
-      missing = []
-      for project in all:
-        if project.gitdir not in fetched:
-          missing.append(project)
-      self._Fetch(*missing)
+        self.manifest._Unload()
+        all = self.GetProjects(args, missing_ok=True)
+        missing = []
+        for project in all:
+          if project.gitdir not in fetched:
+            missing.append(project)
+        self._Fetch(*missing)
 
     for project in all:
       if project.worktree: