angular/angular.dart — pull request #1017 by chirayuk (2014-05-08 07:06:15+00:00)
Title: fix(ng-repeat): handle the ref changing to null and back

This was broken in commit 09871cb29b5345d49929895b2a490360eee69244.

If the ng-repeat expression changed from an iterable to a null,
ng-repeat would not notice it. This would cause further bugs as it
would not reset its state and the ref became a collection again (i.e.
once out of sync, it was gone forever.)

Closes #1015