I have a store where product quantity are set to 0. I have enabled back orders if qty is 0 for a product, however I would like to disable Add to cart in case product is out of stock. This means Add to cart is only available if qty is 0 and In stock is selected in Product Inventory tab. I tried to change couple of settings in System -> Configuration -> Catalog-> Inventory but unable to enable such rule.
Any one who could help?