swanandp/acts_as_list — pull request #27 by bradediger (2012-02-23 20:10:10+00:00)
Title: Efficiency improvement for insert_at when repositioning an existing item

Previously, repositioning an item already in the list required two moves proportional to the total number of items in the list: one to remove the existing item and another to reinsert it. This commit changes the behavior so that only items between the old and new position are renumbered.