mq: cleanup of lookup - handling of None is not relevant Patch specifications in mq is passed around as a string or None. None is generally used when no patch has been specified and there thus is nothing to lookup and the calling code should do something else. One code path did however pass None all the way to lookup. That case was handled in lookup, but there was really need for that, it was undocumented, and it used to cause trouble back when patches was specified as integers.