spree/spree — pull request #5208 by jhawthorn (2014-08-13 21:39:23+00:00)
Title: Fix AvailabilityValidator for saved records

Previously availability only considered inventory_units on the
target_shipment of a line_item. Since target_shipment is not persisted,
a saved line_item would become invalid when its variant ran out of
available inventory even if the inventory_units were already reserved.