puppetlabs/puppetdb — pull request #650 by shakedown (2013-09-13 19:59:49+00:00)
Title: (PE-1452) Allow querying for containing-class=null

Prior to this commit, you could not query for containing-class = null.
This commit provides support for querying against null, and it also
allows for other fields (property, message, file, line) to now be
queried for null.