angular/angular.js — pull request #9667 by dmytroyarmak (2014-10-17 13:33:50+00:00)
Title: fix($rootScope.$on) check listener existense while deregistering

Check that listener is still present in $$listeners before decrease
$$listenerCount. It fixes problem with incorrect $$listenerCount after
call deregistering function multiple times.

Closes #9666