MC-42652: GraphQL - Expected behavior of add product to cart when SKU already exists

Author: Oleksandr Iegorov

app/code/Magento/QuoteGraphQl/Model/Cart/AddSimpleProductToCart.php

@@ -89,11 +89,14 @@ public function execute(Quote $cart, array $cartItemData): void
         }
 
         try {
+            $result = $cart->addProduct($product, $this->buyRequestBuilder->build($cartItemData));
+            /*
             $result = $this->addProductToCartWithConcurrency(
                 $cart,
                 $product,
                 $this->buyRequestBuilder->build($cartItemData)
             );
+            */
         } catch (Exception $e) {
             throw new GraphQlInputException(
                 __(