MC-37484: Cart query error when trying to switch store view

Author: cspruiell

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

@@ -118,6 +118,7 @@ public function execute(string $cartHash, ?int $customerId, int $storeId): Quote
     private function updateCartCurrency(Quote $cart, int $storeId)
     {
         $cartStore = $this->storeRepository->getById($cart->getStoreId());
+        $currentCartCurrencyCode = $cartStore->getCurrentCurrency()->getCode();
         if ((int)$cart->getStoreId() !== $storeId) {
             $newStore = $this->storeRepository->getById($storeId);
             if ($cartStore->getWebsite() !== $newStore->getWebsite()) {
@@ -128,8 +129,10 @@ private function updateCartCurrency(Quote $cart, int $storeId)
             $cart->setStoreId($storeId);
             $cart->setStoreCurrencyCode($newStore->getCurrentCurrency());
             $cart->setQuoteCurrencyCode($newStore->getCurrentCurrency());
-        } else {
+        } elseif ($cart->getQuoteCurrencyCode() !== $currentCartCurrencyCode) {
             $cart->setQuoteCurrencyCode($cartStore->getCurrentCurrency());
+        } else {
+            return;
         }
         $this->cartRepository->save($cart);
     }

app/code/Magento/QuoteGraphQl/Model/Resolver/CartItemPrices.php

@@ -11,13 +11,34 @@
 use Magento\Framework\GraphQl\Config\Element\Field;
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Quote\Model\Cart\Totals;
 use Magento\Quote\Model\Quote\Item;
+use Magento\Quote\Model\Quote\TotalsCollector;
 
 /**
  * @inheritdoc
  */
 class CartItemPrices implements ResolverInterface
 {
+    /**
+     * @var TotalsCollector
+     */
+    private $totalsCollector;
+
+    /**
+     * @var Totals
+     */
+    private $totals;
+
+    /**
+     * @param TotalsCollector $totalsCollector
+     */
+    public function __construct(
+        TotalsCollector $totalsCollector
+    ) {
+        $this->totalsCollector = $totalsCollector;
+    }
+
     /**
      * @inheritdoc
      */
@@ -28,6 +49,12 @@ public function resolve(Field $field, $context, ResolveInfo $info, array $value
         }
         /** @var Item $cartItem */
         $cartItem = $value['model'];
+
+        if (!$this->totals) {
+            // The totals calculation is based on quote address.
+            // But the totals should be calculated even if no address is set
+            $this->totals = $this->totalsCollector->collectQuoteTotals($cartItem->getQuote());
+        }
         $currencyCode = $cartItem->getQuote()->getQuoteCurrencyCode();
 
         return [