Pass empty email & password to ReadOnlyRietveld in dry run of commit queue

commit_queue.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 """Commit queue executable.
 
 Reuse Rietveld and the Chromium Try Server to process and automatically commit
 patches.
 """
 
@@ skipping 206 matching lines @@
         os.path.join(ROOT_DIR, 'subversion_config'))
 
     url = options.rietveld
     gaia_creds = creds.Credentials(os.path.join(work_dir, '.gaia_pwd'))
     if options.dry_run:
       logging.debug('Dry run - skipping SCM check.')
       if options.only_issue:
         parser.error('--only-issue is not supported with dry run')
       else:
         print('Using read-only Rietveld')
-      # Make sure rietveld is not modified.
-      rietveld_obj = rietveld.ReadOnlyRietveld(
-          url,
-          options.user,
-          gaia_creds.get(options.user),
-          None)
+      # Make sure rietveld is not modified. Pass empty email and
+      # password to bypass authentication; this additionally
+      # guarantees rietveld will not allow any changes.
+      rietveld_obj = rietveld.ReadOnlyRietveld(url, email='', password='')
     else:
       AlertOnUncleanCheckout()
       print('WARNING: The Commit Queue is going to commit stuff')
       if options.only_issue:
         print('Using only issue %d' % options.only_issue)
         rietveld_obj = OnlyIssueRietveld(
             url,
             options.user,
             gaia_creds.get(options.user),
             None,
@@ skipping 147 matching lines @@
   # CQ generally doesn't exit by itself, but if we ever get here, it looks
   # like a clean shutdown so remove the landmine file.
   # TODO(phajdan.jr): Do we ever get here?
   os.remove(landmine_path)
   return 0
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   sys.exit(main())