emberjs/ember.js — pull request #4328 by lukemelia (2014-02-08 04:53:37+00:00)
Title: Container throws if injection registered for already instantiated type

Prior to this commit, the container would happily allow you to register an injection for a type that had already been instantiated. This led to confusing-to-debug situations where an injection is registered but a container-created instance doesn't have the injection applied.