Add transparent dash support to commands.

subcommand.py

 # Copyright 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.
 
 """Manages subcommands in a script.
 
 Each subcommand should look like this:
   @usage('[pet name]')
   def CMDpet(parser, args):
     '''Prints a pet.
@@ skipping 101 matching lines @@
         for fn in dir(self.module) if fn.startswith('CMD'))
     cmds.setdefault('help', CMDhelp)
     return cmds
 
   def find_nearest_command(self, name):
     """Retrieves the function to handle a command.
 
     It automatically tries to guess the intended command by handling typos or
     incomplete names.
     """
+    # Implicitly replace foo-bar to foo_bar since foo-bar is not a valid python
+    # symbol but it's faster to type.
+    name = name.replace('-', '_')
     commands = self.enumerate_commands()
     if name in commands:
       return commands[name]
 
     # An exact match was not found. Try to be smart and look if there's
     # something similar.
     commands_with_prefix = [c for c in commands if c.startswith(name)]
     if len(commands_with_prefix) == 1:
       return commands[commands_with_prefix[0]]
 
@@ skipping 110 matching lines @@
         return command(parser, args[1:])
 
     cmdhelp = self.enumerate_commands().get('help')
     if cmdhelp:
       # Not a known command. Default to help.
       self._add_command_usage(parser, cmdhelp)
       return cmdhelp(parser, args)
 
     # Nothing can be done.
     return 2