edx/edx-platform — pull request #2026 by zubair-arbi (2013-12-23 11:04:48+00:00)
Title: Grading types should not allow empty field for "Total Number" and "Numbe...

...r of Droppable"

STUD-988
@cahrens @dmitchell

"Total Number" should be greater than 1(default) and "Number of Droppable" should be an integer.