spree/spree — pull request #5493 by mbj (2014-10-16 20:13:10+00:00)
Title: Fix variant price diff upstream

This fixes a crash in case a products master variants price is `nil`.

[https://circleci.com/gh/MountainRoseHerbs/spree/296](Our CI passes this branch). With the addition of our CI setup that is excluded from this PR.