emberjs/ember.js — pull request #511 by xdissent (2012-02-19 08:24:22+00:00)
Title: The action helper should not trigger events for children of disabled buttons

Events shouldn't be triggered if they originate from within a disabled button, which follows jQuery convention. Coincidentally, this was broken in 1.7.1 when using the `.on()` function (fixed in https://github.com/jquery/jquery/commit/8d9025ca50603e5404c6b50f7fa6c87046ee24c1) but `delegate()` seems to be doing the right thing for us here.