Incorrect Backorder Quantity Handling When Adding Same Product to Cart With Different Custom Options #3446
Description
Preconditions (*)
- Inventory Metapackage Version: 1.2.8-p3
- Product Type: Simple with Custom Options
- Advanced Inventory > Backorders = Allow Qty Below 0 and Notify Customer
Steps to reproduce (*)
- Create a simple product with custom options.
- Set product stock quantity to 10.
- Enable backorders: Catalog > Products > Advanced Inventory > Backorders > Allow Qty Below 0 and Notify Customer
- On frontend, add the same product to the cart twice, each with a different custom option. For each cart item, set quantity to 20.
Expected result (*)
Cart should show correct stock/backorder distribution per line item:
- First cart item:
- Qty ordered: 20
- Available qty: 10
- Backordered qty: 10
- Second cart item:
- Qty ordered: 20
- Available qty: 0
- Backordered qty: 20
- Total ordered qty: 40
- Total available qty deducted: 10
- Total backordered qty: 30
- Admin order view should also reflect correct split per item.
Actual result (*)
- First cart item shows:
- Remaining / backordered qty = 10
- Second cart item shows:
- Backordered qty = 30
- Instead of splitting based on remaining salable qty in stock, Magento assigns incorrect backorder calculation across cart items.
- After order placement, admin order item quantities also show incorrect backorder distribution.
Additional information
I did some research and found that in the file InventorySales/Model/GetBackorder.php, at line number 131, the variable $qtyToCheck is getting the combined total quantity of both products, whereas it should get separate quantities for each product. Because of this, the issue is occurring.