jquery/jquery-ui — pull request #715 by zhizhangchen (2012-08-20 05:38:56+00:00)
Title: Sortable: Calculating item distance and direction using a more robust al...

...gorithm to better support sorting among embeded sortables

Use the item with lowest distance bettween the mouse pointer and
each of its borders to rearrange, the direction of which is
determined by the mouse postion relative to the item, with the
exception when the mouse pointer intersects with the item or
distance is zero, in which case mouse moving direction is used.
Also we use this algorithm to rearrange even when currentContainer
is not changed to override the defective rearranging in _mouseDrag