Prevent diselecting inventory item when left clicking on another invenotry item?

SkyTree

It's been awhile since I asked anything
 How to disable left clicking on another inventory item when you already have an item selected.
At the moment it causes to diselect your current item and bring default cursor.

http://s13.postimg.org/xyd9hseon/Capture.jpg

Thanks.

ChrisIceBox

A similar request was made to make the deselection of inventory items when clicked on unhandled Hotspots optional.  I shall extend it to cover other inventory items as well.