Session::getCart return a Thelia\Model\Cart instance or null if cart is

not valid

core/lib/Thelia/Core/HttpFoundation/Session/Session.php

@@ -25,12 +25,13 @@ namespace Thelia\Core\HttpFoundation\Session;
 
 use Symfony\Component\HttpFoundation\Session\Session as BaseSession;
 use Thelia\Core\Security\User\UserInterface;
-use Thelia\Form\BaseForm;
+use Thelia\Exception\InvalidCartException;
-use Thelia\Model\ConfigQuery;
+use Thelia\Model\Base\CartQuery;
+use Thelia\Model\Cart;
 use Thelia\Tools\URL;
 
-class Session extends BaseSession {
+class Session extends BaseSession
-
+{
     // -- Language ------------------------------------------------------------
 
     public function getLocale()
@@ -122,7 +123,28 @@ class Session extends BaseSession {
      */
     public function getCart()
     {
-        return $this->get("cart_id");
+        $cart_id =  $this->get("cart_id");
+        $cart = null;
+        if ($cart_id) {
+            $cart = CartQuery::create()->findPk($cart_id);
+            try {
+                $this->verifyValidCart($cart);
+            } catch (InvalidCartException $e) {
+                $cart = null;
+            }
+        }
+
+        return $cart;
+    }
+
+    protected function verifyValidCart(Cart $cart)
+    {
+        $customer = $this->getCustomerUser();
+        if ($customer && $cart->getCustomerId() != $customer->getId()) {
+            throw new InvalidCartException("customer in session and customer_id in cart are not the same");
+        } else if($customer === null && $cart->getCustomerId() !== null) {
+            throw new InvalidCartException("Customer exists in cart and not in session");
+        }
     }
 
     /**