emberjs/ember.js — pull request #3289 by hjdivad (2013-09-01 05:22:20+00:00)
Title: `Ember.computed.sort` fallback to guids.

It is now legal for a user's sorting to result in different items counted as
equal for purposes of sorting. Obviously the relative order of items that
are sort-equal is not guaranteed.

The implementation simply uses guids as a deterministic tie-breaker.

This addresses one of the bugs demonstrated by issue 2 in #3273.