zendframework/zf2 — pull request #6129 by samsonasik (2014-04-12 19:32:16+00:00)
Title: change is_null($var) to (null === $var) for consistency

based on @weierophinney commit on https://github.com/zendframework/zf2/commit/ff81ed2122e627e7dfd29430883d63e25c38df23