import argparse

class ArgumentParser(argparse.ArgumentParser):
    """ArgumentParser with quick&dirty hack for #14365.

    .. note::
    
       This fix preserves default argparse behaviour, which some might
       consider as a bug (misleading error information)::

         >>> parser = ArgumentParser()
         >>> subparsers = parser.add_subparsers()
         >>> parser_foo = subparsers.add_parser('foo')
         >>> parser_foo.add_argument('--bar')
         >>> parser.parse_args('--bar baz foo'.split())
         usage: [-h] {foo} ...
         : error: invalid choice: 'baz' (choose from 'foo')

    Read more at http://bugs.python.org/issue14365.

    """
    def _get_option_tuples(self, arg_string):
        option_tuples = super(ArgumentParser, self)._get_option_tuples(arg_string)

        if self._subparsers is None or len(option_tuples) <= 1:
            return option_tuples

        actions = self._subparsers._actions
        
        for action in actions:
            if isinstance(action, argparse._SubParsersAction):
                sub_action = action
                break
        
        subparsers = sub_action.choices.values()
        
        for subparser in subparsers:
            sub_option_tuples = subparser._get_option_tuples(arg_string)
            if len(sub_option_tuples) > 0:
                return []

        return option_tuples