gclient: fetch only what's needed

gclient_scm.py

 # Copyright (c) 2010 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Gclient-specific SCM-specific operations."""
 
 import logging
 import os
 import posixpath
 import re
@@ skipping 239 matching lines @@
         logging.debug("Current branch is not tracking an upstream (remote)"
                       " branch.")
       elif upstream_branch.startswith('refs/remotes'):
         current_type = "branch"
       else:
         raise gclient_utils.Error('Invalid Upstream: %s' % upstream_branch)
 
     # Update the remotes first so we have all the refs.
     for _ in range(10):
       try:
-        remote_output, remote_err = scm.GIT.Capture(
+        if current_type == "branch":
+          remote_output, remote_err = scm.GIT.Capture(
+            ['fetch'] + verbose + ['origin', revision],
+            self.checkout_path,
+            print_error=False)
+        else:
+          remote_output, remote_err = scm.GIT.Capture(
             ['remote'] + verbose + ['update'],
             self.checkout_path,
             print_error=False)
         break
       except gclient_utils.CheckCallError, e:
         # Hackish but at that point, git is known to work so just checking for
         # 502 in stderr should be fine.
         if '502' in e.stderr:
           print str(e)
           print "Sleeping 15 seconds and retrying..."
@@ skipping 657 matching lines @@
     command should be a list of strings that represents an svn command.
 
     This method returns a new list to be used as a command."""
     new_command = command[:]
     if revision:
       new_command.extend(['--revision', str(revision).strip()])
     # --force was added to 'svn update' in svn 1.5.
     if options.force and scm.SVN.AssertVersion("1.5")[0]:
       new_command.append('--force')
     return new_command