Fix depot_tools presubmit's local_rietveld script.

fetch.py

 #!/usr/bin/env python
 # Copyright (c) 2013 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.
 
 """
 Tool to perform checkouts in one easy command line!
 
 Usage:
   fetch <config> [--property=value [--property2=value2 ...]]
@@ skipping 213 matching lines @@
   print textwrap.dedent("""\
     usage: %s [options] <config> [--property=value [--property2=value2 ...]]
 
     This script can be used to download the Chromium sources. See
     http://www.chromium.org/developers/how-tos/get-the-code
     for full usage instructions.
 
     Valid options:
        -h, --help, help   Print this message.
        --nohooks          Don't run hooks after checkout.
+       --force            (dangerous) Don't look for existing .gclient file.
        -n, --dry-run      Don't run commands, only print them.
        --no-history       Perform shallow clones, don't fetch the full git history.
 
     Valid fetch configs:""") % os.path.basename(sys.argv[0])
 
   configs_dir = os.path.join(SCRIPT_PATH, 'fetch_configs')
   configs = [f[:-3] for f in os.listdir(configs_dir) if f.endswith('.py')]
   configs.sort()
   for fname in configs:
     print '  ' + fname
 
   sys.exit(bool(msg))
 
 
 def handle_args(argv):
   """Gets the config name from the command line arguments."""
   if len(argv) <= 1:
     usage('Must specify a config.')
   if argv[1] in ('-h', '--help', 'help'):
     usage()
 
   dry_run = False
   nohooks = False
   no_history = False
+  force = False
   while len(argv) >= 2:

[dsansome, 2016/05/10 07:37:45]

Parsing arguments manually in Python... what year is it?

     arg = argv[1]
     if not arg.startswith('-'):
       break
     argv.pop(1)
     if arg in ('-n', '--dry-run'):
       dry_run = True
     elif arg == '--nohooks':
       nohooks = True
     elif arg == '--no-history':
       no_history = True
+    elif arg == '--force':
+      force = True
     else:
       usage('Invalid option %s.' % arg)
 
   def looks_like_arg(arg):
     return arg.startswith('--') and arg.count('=') == 1
 
   bad_parms = [x for x in argv[2:] if not looks_like_arg(x)]
   if bad_parms:
     usage('Got bad arguments %s' % bad_parms)
 
   config = argv[1]
   props = argv[2:]
   return (
-      optparse.Values(
-          {'dry_run':dry_run, 'nohooks':nohooks, 'no_history': no_history }),
+      optparse.Values({
+        'dry_run': dry_run,
+        'nohooks': nohooks,
+        'no_history': no_history,
+        'force': force}),
       config,
       props)
 
 
 def run_config_fetch(config, props, aliased=False):
   """Invoke a config's fetch method with the passed-through args
   and return its json output as a python object."""
   config_path = os.path.abspath(
       os.path.join(SCRIPT_PATH, 'fetch_configs', config))
   if not os.path.exists(config_path + '.py'):
@@ skipping 23 matching lines @@
           method (checkout type, repository url, etc.).
       root: The directory into which the repo expects to be checkout out.
   """
   assert 'type' in spec
   checkout_type = spec['type']
   checkout_spec = spec['%s_spec' % checkout_type]
   try:
     checkout = CheckoutFactory(checkout_type, options, checkout_spec, root)
   except KeyError:
     return 1
-  if checkout.exists():
+  if not options.force and checkout.exists():
     print 'Your current directory appears to already contain, or be part of, '
     print 'a checkout. "fetch" is used only to get new checkouts. Use '
     print '"gclient sync" to update existing checkouts.'
     print
     print 'Fetch also does not yet deal with partial checkouts, so if fetch'
     print 'failed, delete the checkout and start over (crbug.com/230691).'
     return 1
   return checkout.init()
 
 
 def main():
   options, config, props = handle_args(sys.argv)
   spec, root = run_config_fetch(config, props)
   return run(options, spec, root)
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main())
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)