emberjs/ember.js — pull request #253 by svenfuchs (2011-12-13 21:28:15+00:00)
Title: Do not try to destroy a childView that does not exist

I was getting an `Uncaught TypeError: Cannot call method 'destroy' of undefined` under conditions that I can't reproduce reliably (as in: click around for a while, sometimes it happens, most of the times it doesn't)

I guess this just covers a bug or weird condition somewhere else, but checking for the childView fixes this.