[Zope-dev] range:max, date times and pluggableindexes

In Zope 2.3.3 we did this with ZCatalog, on a field index: query['effective_date'] = ['', DateTime.now()] query['effective_date_usage'] = 'range:max' This returns all records where the effective_date is lower than todays date OR the effective_date is an empty string. In Zope 2.5.1, the same code now returns *all* records. It seems like now suddenly comparing dates and an empty string always returns true. Question 1: Is there a way to solve this without having to do two separate queries? Question 2: Is it really true that comparing dates and en empty string returns true, no matter what? If that is the case (which it seems to be) then I think it's a bug, unless somebody as very good arguments. :-) Whaddayousay?