projectblacklight/blacklight — pull request #545 by cfitz (2013-03-12 07:02:32+00:00)
Title: BM Controller returns 204 instead of 200 w/ empty body

http://jquery.com/upgrade-guide/1.9/#jquery-ajax-returning-a-json-result-of-an-empty-string

jQuery 1.9 ajax doesn't like 200's with empty bodies. a bit annoying but technically this is correct since it's not valid json. returning a 204 ( i.e. head :no_content ) instead corrects this.