emberjs/ember.js — pull request #3933 by rjackson (2013-12-14 21:46:35+00:00)
Title: [BUGFIX beta] Do not attempt to serialize undefined models.

If a routes model is undefined do not attempt to serialize it.

Previously, this would cause an error like: `Cannot call get with 'id' on an undefined object.`.

Resolves #3859.