Hidden item copies remaining in lists while dragging

[petrinecp]

Hi, I've tried upgrading from 1.5.0-rc1 to 1.5.1 but the dragging behavior has changed slightly. After dragging an item from list A to B while still holding the mouse button down, the list A contains a hidden copy of the dragged item (styled by display: none). I'm highlighting the empty lists with CSS pseudo selector :empty, but the selector won't apply in this case. After releasing the mouse button the hidden element is removed, this was fixed in 1.5.1 (issues referring to that problem #1046, #1091) but this issue is different. I've created two jsbins to demonstrate the issue. Try dragging an item from one list to another (do not release the mouse button) which should empty the first list and apply border to it. Only after releasing the mouse button the empty list gets highlighted with v1.5.1.

v1.5.0-rc1
http://jsbin.com/fazirojabo/1/edit?html,css,js,output

v1.5.1
http://jsbin.com/gafitezaca/edit?html,css,js,output

[owen-m1]

Solved in 1.8.0 with removeOnClone option (defaults to true, so the old behavior is the default now).