draggable/droppable scope bug

draggable/droppable scope bug

Apparently there is a bug in the implementation for the scope option in draggables and droppables. I couldn't get scope to behave so I asked a question on Stackoverflow and got a very helpful and informative response from user Simen Echholt. I'm not a jQuery contributer, nor am I familiar with jQuery's internals, so I don't know if this is a known bug or not, but I'm posting here just in case.
 
My original example is on jsbin here, and Simen's edit with his jQuery extension to fix the issue is here. For convenience I'll exerpt his response describing the bug below:

There's a bug in jQuery when setting the scope option of a droppable via the option function. jQuery maintains an array with all registered sortables (let's call it S for now), where each key is one specific scope. When you drop a draggable element into the droppable, jQuery then checks the scope attribute of the draggable and checks if the droppable you are trying to drag into is present in S[scope]. If it isn't it means that the droppable you are tring to drop into is not in the same scope as the draggable.
 
The problem is that when you change the scope option by doing .droppable('option', 'scope', ...), the array S isn't updated. Everything else (as far as I can see) is updated correctly (option attribute of the actual jQuery object etc), leading to "correct" results being returned when getting the scope option via .droppable('option', 'scope').

The "S" he refers to is $.ui.ddmanager.droppables.