Exception in selection plugin when loading hidden editor

[Josh Nisly]

If CKEditor is loaded in a hidden element, getRanges() in the selection plugin throws a JavaScript exception, since getNative returns null, and the return value isn't checked. Adding

if (sel === null)
   return [];

on line 447 of selection/plugin.js fixes the problem for me.

This problem can be duplicated in replace-by-class by adding "display: none" to the containing <p> element's style.

[Frederico Caldeira Knabben]

To check objects, it's not necessary to compare then with null. You did it well in line 580, but used a different style in line 525. Also, at that point you can safely check for "nativeRange", instead of "sel". In this way we make two checks in a single move.

So, for the addition at line 525:

if ( !nativeRange )
	return [];

Please make that change and go ahead committing it.

[Artur Formella]

Fixed with [3346]