Added hyphen-only options

git_new_branch.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 import argparse
 import sys
 
 import subprocess2
 
 from git_common import run, root, set_config, get_or_create_merge_base, tags
 from git_common import hash_one
 
 
 def main(args):
   parser = argparse.ArgumentParser(
     formatter_class=argparse.ArgumentDefaultsHelpFormatter
   )
   parser.add_argument('branch_name')
   g = parser.add_mutually_exclusive_group()
-  g.add_argument('--upstream_current', action='store_true',
+  g.add_argument('--upstream-current', '--upstream_current',
+                 action='store_true',
                  help='set upstream branch to current branch.')
   g.add_argument('--upstream', metavar='REF', default=root(),
                  help='upstream branch (or tag) to track.')
   g.add_argument('--lkgr', action='store_const', const='lkgr', dest='upstream',
                  help='set basis ref for new branch to lkgr.')
 
   opts = parser.parse_args(args)
 
   try:
     if opts.upstream_current:
@@ skipping 12 matching lines @@
     get_or_create_merge_base(opts.branch_name)
   except subprocess2.CalledProcessError as cpe:
     sys.stdout.write(cpe.stdout)
     sys.stderr.write(cpe.stderr)
     return 1
   sys.stderr.write('Switched to branch %s.\n' % opts.branch_name)
 
 
 if __name__ == '__main__':  # pragma: no cover
   sys.exit(main(sys.argv[1:]))