spree/spree — pull request #3746 by gwik (2013-09-20 11:05:17+00:00)
Title: Product#save_master callback makes the master always saved

The bug makes the master variant of a product saved each time a product is saved.

A nasty side effect is that the master variant is saved every time an object associates a variant or a product.
For example it saves the variant (and by side effect the product) every time the cart is updated.