jquery/jquery — pull request #1030 by maranomynet (2012-11-17 01:37:54+00:00)
Title: Fixing borked .show() on CSS hidden elements in Firefox when iframe/body/html is also hidden (Bug 12904)

bug is demonstrated here http://jsfiddle.net/qT4Tg/3/

BTW, this bug affects the `master` and `1.8-stable` branches equally.