HomePhabricator

rebase: use cmdutil.check_at_most_one_arg() for action

Authored by martinvonz.

Description

rebase: use cmdutil.check_at_most_one_arg() for action

Here we also needed to know what the action was (if any), so I've
updated the helper to return any specified option.

Differential Revision: https://phab.mercurial-scm.org/D7640