This is a major functional overhaul, and should introduce some significant performance benefits, but may also introduce bugs and should not be merged lightly. This needs to be thoroughly tested, ideally in all scenarios where wpsc_get_order() is used.
This PR builds on top of https://github.com/wp-e-commerce/WP-e-Commerce/pull/2254.
This is a major functional overhaul, and should introduce some significant performance benefits, but may also introduce bugs and should not be merged lightly. This needs to be thoroughly tested, ideally in all scenarios where
wpsc_get_order()is used.