ACP2E-3646: Addresses selection is not saved when we "Check Out with Multiple Addresses"

Author: aplapana

app/code/Magento/Multishipping/Model/Cart/MultishippingClearItemAddress.php

@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2025 Adobe
+ * All Rights Reserved.
  */
 declare(strict_types=1);
 
@@ -74,6 +74,7 @@ public function __construct(
     /**
      * Cleans shipping addresses and item assignments after MultiShipping flow
      *
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      * @param Cart|UpdateItemQty $subject
      * @param RequestInterface $request
      * @throws LocalizedException
@@ -95,7 +96,6 @@ public function clearAddressItem($subject, $request)
             }
 
             if ($currentShippingAddress) {
-                $defaultShipping = $currentShippingAddress->getCustomerAddressId();
                 $quote->addShippingAddress($currentShippingAddress);
             } else {
                 $shippingAddress = $quote->getShippingAddress();

app/code/Magento/Multishipping/Model/Checkout/Type/Multishipping.php

@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2025 Adobe
+ * All Rights Reserved.
  */
 
 namespace Magento\Multishipping\Model\Checkout\Type;
@@ -277,6 +277,8 @@ public function __construct(
      *
      * @return \Magento\Multishipping\Model\Checkout\Type\Multishipping
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     * @throws LocalizedException
      */
     protected function _init()
     {
@@ -295,6 +297,7 @@ protected function _init()
              * Remove all addresses
              */
             $addresses = $quote->getAllAddresses();
+            $defaultShippingId = null;
             foreach ($addresses as $address) {
                 if ($address->getAllItems()) {
                     $defaultShippingId = $address->getCustomerAddressId();

app/code/Magento/Multishipping/Test/Unit/Model/Cart/MultishippingClearItemAddressTest.php

@@ -94,7 +94,8 @@ public function testClearAddressItem(
             'getAllShippingAddresses',
             'removeAddress',
             'getShippingAddress',
-            'getCustomer'
+            'getCustomer',
+            'addShippingAddress'
         ]);
         $requestMock->method('getActionName')
             ->willReturn($actionName);
@@ -119,6 +120,9 @@ public function testClearAddressItem(
         $customerMock = $this->getMockForAbstractClass(CustomerInterface::class);
         $quoteMock->method('getCustomer')
             ->willReturn($customerMock);
+        $quoteMock->method('addShippingAddress')
+            ->with($shippingAddressMock)
+            ->willReturnSelf();
         $customerMock->method('getDefaultShipping')
             ->willReturn($customerAddressId);