The ZCatalog treats an empty *string* in a special way to support search forms: an empty string is considered as "no restriction".
A ":lines" control does not return a string but a list. An empty list is not considered as "no restriction".
What you see here, is a bug in the "AND" implementation of "KeywordIndex". An empty list together with the "AND" operator should be interpreted as "no restriction". Due to the bug, it is considered as "no results".
I've solved it in /PluginIndexes/common/util.py. When the param is a record, around line 95, I've added: if keys == ['']: keys = None Is it correct? Seems to work with all indexes I've and KeywordIndexes, which works also with AND as operator. ________________________________________________ Message sent using ALFANET Caorle WEBMAIL 1.0