Automattic/jetpack — pull request #310 by xyu (2014-03-06 16:52:05+00:00)
Title: Module Related Posts: IE9 Compat Fix

IE9 does not support `history.replaceState()` which breaks rendering of the
related posts section. Abort trying to cleaning up the URL if we cannot
rewrite state. (Sadly this leaves cruft on the URL of older browsers.)