gclient: fix regression in revision handling code in GitWrapper::update

gclient_scm.py

 # Copyright (c) 2009 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 re
 import subprocess
@@ skipping 101 matching lines @@
 
     if args:
       raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
 
     url, revision = gclient_utils.SplitUrlRevision(self.url)
     rev_str = ""
     if options.revision:
       # Override the revision number.
       revision = str(options.revision)
     if revision:
-      url = '%s@%s' % (url, revision)
       rev_str = ' at %s' % revision
 
     if options.verbose:
       print("\n_____ %s%s" % (self.relpath, rev_str))
 
     if not os.path.exists(self.checkout_path):
       self._Run(['clone', url, self.checkout_path],
                 cwd=self._root_dir, redirect_stdout=False)
       if revision:
         self._Run(['reset', '--hard', revision], redirect_stdout=False)
@@ skipping 321 matching lines @@
           self.ReplaceAndPrint(line)
         else:
           if (line.startswith(self.original_prefix) or
               line.startswith(self.working_prefix)):
             self.ReplaceAndPrint(line)
           else:
             print line
 
     filterer = DiffFilterer(self.relpath)
     self.RunAndFilterOutput(command, path, False, False, filterer.Filter)