Back buffer can be left in unknown state

[johncridges]

When setting Starling.shareContext false, the back buffer is not necessarily set back to the Starling viewport. I suggest the following change in Starling.as:

        public function set shareContext(value : Boolean) : void
        {
            if (!value) {
                _previousViewPort.setEmpty();
            }
            _painter.shareContext = value;
        }

[PrimaryFeather]

Thanks a lot for the heads-up and the suggested fix, John! Makes sense.