In Magento 2, on the checkout page where the cart items are displayed, when I modify the quantity to be higher than the available stock, only the available quantity (stock quantity) is shown. However, I notice that the subtotal calculation is incorrect as it is based on the desired quantity rather than the displayed quantity ( stock quantity) .
Furthermore, if I order another product and modify its quantity, I observe that the subtotal for the first product is displayed correctly, taking into account the displayed value (stock quantity).
I adjusted the entered quantity to the stock quantity if the entered quantity is greater than the stock quantity.
I want to give an example. I have a product with a unit price of $100 and a stock quantity of 1300. I want to order 1500 (1500 > 1300). The system displays 1300 in the quantity field (the stock quantity), but the subtotal calculation is incorrect: $150,000 (1500 * $100), whereas I want the subtotal to be $130,000 (1300 * $100) because I displayed 1300.
This is the code in the default.phtml file of the checkout module.
value=”getQty() > $qty_stock ? $qty_stock : $block->getQty(); ?>