Fix a logic error

gcl.py

 #!/usr/bin/python
 # Copyright (c) 2006-2009 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.
 
 """Wrapper script around Rietveld's upload.py that groups files into
 changelists."""
 
 import getpass
 import os
@@ skipping 618 matching lines @@
 
 
 def CMDstatus(argv):
   """Lists modified and unknown files in the current directory down."""
   __pychecker__ = 'unusednames=argv'
   return ListFiles(True)
 
 
 def CMDhelp(argv=None):
   """Prints this help or help for the given command."""
-  if len(argv) > 2:
+  if argv and len(argv) > 2:
     if argv[2] == 'try':
       TryChange(None, ['--help'], swallow_exception=False)
       return 0
     if argv[2] == 'upload':
       upload.RealMain(['upload.py', '--help'])
       return 0
 
   print (
 """GCL is a wrapper for Subversion that simplifies working with groups of files.
 version """ + __version__ + """
@@ skipping 672 matching lines @@
       return 0
     args =["svn", command]
     root = GetRepositoryRoot()
     args.extend([os.path.join(root, x) for x in change_info.GetFileNames()])
     RunShell(args, True)
   return 0
 
 
 if __name__ == "__main__":
   sys.exit(main())