edx/edx-platform — pull request #6246 by zubair-arbi (2014-12-15 12:49:43+00:00)
Title: fix location revision error for multi parent draft

PLAT-332
@adampalay @dmitchell
Fix problem where a component has multiple parents (of which all other parents except original parent could be orphans) and when user tires to export the course with draft version of that component then "get_parent_location" method raises "AssertionError" for location revision of that component.