diff -r 6e1c79578e5c -r 7aac35ada1cb mercurial/match.py --- a/mercurial/match.py Wed Mar 15 15:05:54 2017 -0700 +++ b/mercurial/match.py Wed Mar 15 15:08:45 2017 -0700 @@ -117,8 +117,10 @@ the same directory '' - a pattern of the specified default type """ - include = include or [] - exclude = exclude or [] + if include is None: + include = [] + if exclude is None: + exclude = [] self._root = root self._cwd = cwd