In the parameters system, we have been checking for a positive list of values
which get converted to None. The problem is that this method can in some
cases throw warnings when type coercion doesn't work (particularly, string
to unicode). Instead, any values that evaluate to False that are neither
numeric nor boolean should be converted to None.
Reviewed-By: Jan Pazdziora <jpazdziora@redhat.com>
Tomas Babej
Nathaniel McCallum
Petr Viktorin