magento 1.9.3 exceeding stock price error

Question

Scenario: There is a product in the cart but it only has limited stock. This one has only 1 item in stock.

We exceed the quantity of the product. I set the quantity to 2.

The price changes to less than half of the original price.

I searched everywhere for a solution including editing the codes for the price to changing settings in the backend.

Then I found this in the magento forums:

https://community.magento.com/t5/Version-Upgrades/Cart-displays-wrong-price-after-exceeding-stock-value-Version-1/td-p/54002

Does anyone know where this error is stemming from?

Answer 1

This "bug" was introduced in Magento CE 1.9.3.0 by the following modification in app/code/core/Mage/Sales/Model/Quote/Address/Total/Subtotal.php:

             $item->setPrice($finalPrice)
                 ->setBaseOriginalPrice($finalPrice);
             $item->calcRowTotal();
-        } else if (!$quoteItem->getParentItem()) {
+        } else if (!$quoteItem->getParentItem() && !$item->getHasError()) {
             $finalPrice = $product->getFinalPrice($quoteItem->getQty());
             $item->setPrice($finalPrice)
                 ->setBaseOriginalPrice($finalPrice);

Because of this the quote calculation isn't done correctly anymore. I don't find a reasonable notification for this in the CE 1.9.3.0 release notes.

I fixed this problem by rewriting this modification back to the CE 1.9.2.x behaviour.

    <models>
        ...
        <sales>
            <rewrite>
                <quote_address_total_subtotal>Mypackage_Mymodule_Model_Sales_Quote_Address_Total_Subtotal</quote_address_total_subtotal>
            </rewrite>
        </sales>
    </models>

and Mypackage_Mymodule_Model_Sales_Quote_Address_Total_Subtotal

<?php
class Mypackage_Mymodule_Model_Sales_Quote_Address_Total_Subtotal extends Mage_Sales_Model_Quote_Address_Total_Subtotal
{
    /**
     * Address item initialization
     *
     * @param  $item
     * @return bool
     */
    protected function _initItem($address, $item)
    {
        ...
        } else if (!$quoteItem->getParentItem()) {
            $finalPrice = $product->getFinalPrice($quoteItem->getQty());
        ...
}

Answer 2

The issue and a possible solution is described in the Magento Forums:

+++ app/code/core/Mage/Sales/Model/Quote/Address/Total/Subtotal.php 2017-03-15 10:53:47.000000000 +0000
@@ -110,16 +110,17 @@
             );
             $item->setPrice($finalPrice)
                 ->setBaseOriginalPrice($finalPrice);
-            $item->calcRowTotal();
+//            $item->calcRowTotal();
         } else if (!$quoteItem->getParentItem() && !$item->getHasError()) {
             $finalPrice = $product->getFinalPrice($quoteItem->getQty());
             $item->setPrice($finalPrice)
                 ->setBaseOriginalPrice($finalPrice);
-            $item->calcRowTotal();
+//            $item->calcRowTotal();
             $this->_addAmount($item->getRowTotal());
             $this->_addBaseAmount($item->getBaseRowTotal());
             $address->setTotalQty($address->getTotalQty() + $item->getQty());
         }
+        $item->calcRowTotal();

         return true;
     }

Answer 3

Removing following from the Mage_Sales_Model_Quote_Address_Total_Subtotal _initItem() method solved it for me:

&& !$item->getHasError()

I have checked this and it is working fine for me