mongodb/mongo — pull request #783 by Michael-karn-ivanov (2014-09-19 15:09:35+00:00)
Title: SERVER-8514 $in count query with null array yields error on empty collection when $in syntax invalid

query canonicalization is perfromed before executor would return if no collection exists. So if we call invalid query on non-existing collection status of invalid query will return before it reports 0 records on non-existing collection