Fix undefined default_config_path_bak in gsutil config.

third_party/gsutil/gslib/commands/config.py

 # Copyright 2011 Google Inc. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 576 matching lines @@
       raise CommandException(
           'OAuth2 is only supported when running under Python 2.6 or later\n'
           '(unless additional dependencies are installed, '
           'see README for details);\n'
           'you are running Python %s.\nUse "gsutil config -a" to create a '
           'config with Developer Key authentication credentials.' % sys.version)
 
     if not scopes:
       scopes.append(SCOPE_FULL_CONTROL)
 
+    default_config_path_bak = None
     if output_file_name is None:
       # Check to see if a default config file name is requested via
       # environment variable. If so, use it, otherwise use the hard-coded
       # default file. Then use the default config file name, if it doesn't 
       # exist or can be moved out of the way without clobbering an existing 
       # backup file.
       boto_config_from_env = os.environ.get('BOTO_CONFIG', None)
       if boto_config_from_env:
         default_config_path = boto_config_from_env
       else:
         default_config_path = os.path.expanduser(os.path.join('~', '.boto'))
       if not os.path.exists(default_config_path):
         output_file_name = default_config_path
-        default_config_path_bak = None
       else:
         default_config_path_bak = default_config_path + '.bak'
         if os.path.exists(default_config_path_bak):
           raise CommandException('Cannot back up existing config '
               'file "%s": backup file exists ("%s").'
               % (default_config_path, default_config_path_bak))
         else:
           try:
             sys.stderr.write(
                 'Backing up existing config file "%s" to "%s"...\n'
@@ skipping 32 matching lines @@
 
     if output_file_name != '-':
       output_file.close()
       sys.stderr.write(
           '\nBoto config file "%s" created.\n' % output_file_name)
 
     return 0
 
 def cleanup_handler(signalnum, handler):
   raise AbortException('User interrupted config command')