MAGETWO-69223: Fix for #9646 #9647

Author: ishakhsuvarov

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

@@ -12,6 +12,7 @@
 use Magento\Framework\Api\DataObjectHelper;
 use Magento\Quote\Model\Cart\Totals\ItemConverter;
 use Magento\Quote\Api\CouponManagementInterface;
+use Magento\Framework\Api\ExtensibleDataInterface;
 
 /**
  * Cart totals data object.
@@ -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();