emberjs/data — pull request #925 by mostlystatic (2013-04-26 13:12:10+00:00)
Title: Fixture id of zero shouldn't be raise an undefined id property error

Currently defined falsy values can raise an error like this:

> Uncaught Error: the id property must be defined for fixture {"id":0 /* ... */}

The updated code checks for `undefined` instead.