Ember.computed.sort fails on 2.x with null list (worked in 1.13)

[workmanw]

When the target of Ember.computed.sort is null it causes a crash on the 2.x branch. It worked on the Ember 1.13.x branch.

Ember 1.13.9: http://emberjs.jsbin.com/mejidiniju/1/edit
Ember 2.1-beta.2: http://emberjs.jsbin.com/pujaxeceqe/1/edit

[stefanpenner]

Should be fixed on master

[fivetanley]

@stefanpenner still present on master http://emberjs.jsbin.com/pucelamoce/1/edit?html,css,js,output

[workmanw]

@stefanpenner @fivetanley Seems like the easiest solution is to check items for null and bail early here: https://github.com/emberjs/ember.js/blob/master/packages/ember-runtime/lib/computed/reduce_computed_macros.js#L573

I can submit a pull if you think that's the way to go. I'm not really up on Ember's style guide anymore :(

[rwjblue]

We did a similar fix to Ember.computed.sum in #12170. Seems like we need to add a similar guard to Ember.computed.sort.

@workmanw - Can you take a look at the PR above, and submit a PR?

[stefanpenner]

Ah sort not map

[workmanw]

@rwjblue @stefanpenner Yea, I'll make it so.