As of now, queries like the above with empty, or like http://en.wikipedia.org/w/api.php?action=query&list=recentchanges&rcnamespace=foo with only invalid multivalue parameters cause an MW-exception in most list= modules.

A way to handle that would perhaps be to fall back to the default value or to throw an appropriate api error.

Version: 1.14.x
Severity: minor
URL: http://en.wikipedia.org/w/api.php?action=query&list=recentchanges&rcnamespace