spree/spree — pull request #3434 by huoxito (2013-07-24 20:12:50+00:00)
Title: Do not check stock quantity twice when saving line item

Every time an user pressed the add to cart button spree was checking
stock in OrderPopulator and before saving the line item, through
Stock::AvailabilityValidator. I believe we only need to check stock on
the LineItem model