Assigning CCLayer.Viewport throws uninformative exception

[vchelaru]

Sample code:

var newViewport = new CCViewport(new CCRect(0,0, this.ContentSize.Width, this.ContentSize.Height),
    CCDisplayOrientation.Portrait);
layer.Viewport = newViewport;

Exception:

{System.NullReferenceException: Object reference not set to an instance of an object
  at CocosSharp.CCNode.set_Viewport (CocosSharp.CCViewport value) [0x00006] in <filename unknown>:0 
  at CoinTimeGame.Scenes.GameScene.ClipLayerForInputUi (CocosSharp.CCLayer layer) [0x0002e] in c:\Users\Victor\Documents\mobile-samples\CoinTime\CoinTime\Scenes\GameScene.cs:143 } System.NullReferenceException

layer is not null - the exception is occurring within the setter.

Expected result is that the exception should tell the user why this is an invalid operation, or to not throw an exception.

[rtabbara]

With the upcoming ability to embed a view using CCGameView, a user can simply resize the view and hence the CCViewport class has been made redundant.