ACP2E-2174: allow qty change for cart items without errors

Author: alzota

app/code/Magento/Checkout/Controller/Cart/UpdateItemQty.php

@@ -129,12 +129,12 @@ public function execute()
     private function updateItemQuantity(Item $item, float $qty)
     {
         if ($qty > 0) {
-            $item->clearMessage();
-            $item->setHasError(false);
-            $item->setQty($qty);
-
             if ($item->getHasError()) {
                 throw new LocalizedException(__($item->getMessage()));
+            } else {
+                $item->clearMessage();
+                $item->setHasError(false);
+                $item->setQty($qty);
             }
         }
     }

app/code/Magento/Checkout/Controller/Cart/UpdatePost.php

@@ -83,6 +83,7 @@ protected function _updateShoppingCart()
                 $this->cart->updateItems($cartData)->save();
             }
         } catch (\Magento\Framework\Exception\LocalizedException $e) {
+            $this->cart->save();
             $this->messageManager->addErrorMessage(
                 $this->_objectManager->get(\Magento\Framework\Escaper::class)->escapeHtml($e->getMessage())
             );

app/code/Magento/Checkout/Model/Cart.php

@@ -522,6 +522,7 @@ public function updateItems($data)
         );
 
         $qtyRecalculatedFlag = false;
+        $deferredErrors = [];
         foreach ($data as $itemId => $itemInfo) {
             $item = $this->getQuote()->getItemById($itemId);
             if (!$item) {
@@ -535,12 +536,13 @@ public function updateItems($data)
 
             $qty = isset($itemInfo['qty']) ? (double)$itemInfo['qty'] : false;
             if ($qty > 0) {
-                $item->clearMessage();
-                $item->setHasError(false);
-                $item->setQty($qty);
-
                 if ($item->getHasError()) {
-                    throw new \Magento\Framework\Exception\LocalizedException(__($item->getMessage()));
+                    $deferredErrors[$item->getId()] = __($item->getMessage());
+                    continue;
+                } else {
+                    $item->clearMessage();
+                    $item->setHasError(false);
+                    $item->setQty($qty);
                 }
 
                 if (isset($itemInfo['before_suggest_qty']) && $itemInfo['before_suggest_qty'] != $qty) {
@@ -564,6 +566,10 @@ public function updateItems($data)
             ['cart' => $this, 'info' => $infoDataObject]
         );
 
+        if (count($deferredErrors)) {
+            throw new \Magento\Framework\Exception\LocalizedException(current($deferredErrors));
+        }
+
         return $this;
     }