gclient would crash when .gclient is not found.

gclient_utils.py

 # Copyright (c) 2011 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.
 
 """Generic utils."""
 
 import errno
 import logging
 import os
 import Queue
@@ skipping 434 matching lines @@
       return path
     (new_path, _) = os.path.split(path)
     if new_path == path:
       return None
     path = new_path
 
 
 def GetGClientRootAndEntries(path=None):
   """Returns the gclient root and the dict of entries."""
   config_file = '.gclient_entries'
-  config_path = os.path.join(FindFileUpwards(config_file, path), config_file)
-
-  if not config_path:
+  root = FindFileUpwards(config_file, path)
+  if not root:
     print "Can't find %s" % config_file
     return None
-
+  config_path = os.path.join(root, config_file)
   env = {}
   execfile(config_path, env)
   config_dir = os.path.dirname(config_path)
   return config_dir, env['entries']
 
 
 def lockedmethod(method):
   """Method decorator that holds self.lock for the duration of the call."""
   def inner(self, *args, **kwargs):
     try:
@@ skipping 197 matching lines @@
         logging.info('Caught exception in thread %s' % self.item.name)
         logging.info(str(sys.exc_info()))
         work_queue.exceptions.put(sys.exc_info())
       logging.info('_Worker.run(%s) done' % self.item.name)
 
       work_queue.ready_cond.acquire()
       try:
         work_queue.ready_cond.notifyAll()
       finally:
         work_queue.ready_cond.release()