mozilla-b2g/gaia — pull request #7766 by hsinyi (2013-01-24 07:27:10+00:00)
Title: Bug 818623 -  [Dialer] if an outside call hangs up and calls again, the second call does not ring nor give the incoming overlay 

The main concept of this patch is that 'exitCallScreen' when we got notified there's no call.
@etiennesegonzac