MAGETWO-86886: #12993: Type error in Cart/Totals [Forwardport for pub…

…lic PR#9647] #1186

 - Merge Pull Request magento-engcom/magento2ce#1186 from p-bystritsky/magento2:ISSUE-12993
 - Merged commits:
   1. 69cad44
   2. dc64138

app/code/Magento/Quote/Model/Cart/CartTotalRepository.php

@@ -10,6 +10,7 @@
 use Magento\Quote\Api\CartTotalRepositoryInterface;
 use Magento\Catalog\Helper\Product\ConfigurationPool;
 use Magento\Framework\Api\DataObjectHelper;
+use Magento\Framework\Api\ExtensibleDataInterface;
 use Magento\Quote\Model\Cart\Totals\ItemConverter;
 use Magento\Quote\Api\CouponManagementInterface;
 
@@ -94,6 +95,7 @@ public function get($cartId)
             $addressTotalsData = $quote->getShippingAddress()->getData();
             $addressTotals = $quote->getShippingAddress()->getTotals();
         }
+        unset($addressTotalsData[ExtensibleDataInterface::EXTENSION_ATTRIBUTES_KEY]);
 
         /** @var \Magento\Quote\Api\Data\TotalsInterface $quoteTotals */
         $quoteTotals = $this->totalsFactory->create();