search for: match_nothing

...ents. I've put a patch together to fix this issue, but it requires the introduction of a new query operator, to mark a query as matching no documents (as opposed to a query created with the default query constructor, which represents an undefined query). I've called this operator "OP_MATCH_NOTHING", and it takes no subqueries. I believe this should be public, since it may be useful for people trying to write their own query parsers, rather than relying on the builtin query parser. It's possible that a similar approach would be a neat solution for representing "alldocument&quo...