ACP2E-3143: PayPal order refund results in duplicate credit memo

Author: dyushkin

app/code/Magento/Paypal/Model/Ipn.php

@@ -7,10 +7,12 @@
 namespace Magento\Paypal\Model;
 
 use Exception;
+use Magento\Framework\App\ObjectManager;
 use Magento\Framework\Exception\LocalizedException;
 use Magento\Sales\Model\Order;
 use Magento\Sales\Model\Order\Email\Sender\CreditmemoSender;
 use Magento\Sales\Model\Order\Email\Sender\OrderSender;
+use Magento\Sales\Model\OrderMutexInterface;
 
 /**
  * PayPal Instant Payment Notification processor model
@@ -46,13 +48,19 @@ class Ipn extends \Magento\Paypal\Model\AbstractIpn implements IpnInterface
     protected $creditmemoSender;
 
     /**
-     * @param \Magento\Paypal\Model\ConfigFactory $configFactory
+     * @var OrderMutexInterface|null
+     */
+    private ?OrderMutexInterface $orderMutex;
+
+    /**
+     * @param ConfigFactory $configFactory
      * @param \Psr\Log\LoggerInterface $logger
      * @param \Magento\Framework\HTTP\Adapter\CurlFactory $curlFactory
      * @param \Magento\Sales\Model\OrderFactory $orderFactory
      * @param Info $paypalInfo
      * @param OrderSender $orderSender
      * @param CreditmemoSender $creditmemoSender
+     * @param OrderMutexInterface|null $orderMutex
      * @param array $data
      */
     public function __construct(
@@ -63,13 +71,15 @@ public function __construct(
         Info $paypalInfo,
         OrderSender $orderSender,
         CreditmemoSender $creditmemoSender,
+        ?OrderMutexInterface $orderMutex = null,
         array $data = []
     ) {
         parent::__construct($configFactory, $logger, $curlFactory, $data);
         $this->_orderFactory = $orderFactory;
         $this->_paypalInfo = $paypalInfo;
         $this->orderSender = $orderSender;
         $this->creditmemoSender = $creditmemoSender;
+        $this->orderMutex = $orderMutex ?: ObjectManager::getInstance()->get(OrderMutexInterface::class);
     }
 
     /**
@@ -466,6 +476,21 @@ protected function _registerPaymentReversal()
      * @return void
      */
     protected function _registerPaymentRefund()
+    {
+        return $this->orderMutex->execute(
+            (int) $this->_order->getEntityId(),
+            \Closure::fromCallable([$this, 'processRefund'])
+        );
+    }
+
+    /**
+     * Process a refund
+     *
+     * @return void
+     * @throws Exception
+     * @SuppressWarnings(PHPMD.UnusedPrivateMethod) This method is used in closure callback
+     */
+    private function processRefund()
     {
         $this->_importPaymentInformation();
         $reason = $this->getRequestData('reason_code');

dev/tests/integration/testsuite/Magento/Paypal/Model/IpnTest.php

@@ -80,6 +80,46 @@ public function testProcessIpnRequestFullRefund()
         $this->assertEmpty($order->getTotalOfflineRefunded());
     }
 
+    /**
+     * Refund full order amount by Paypal Express IPN message service with concurrent requests.
+     *
+     * @magentoDataFixture Magento/Paypal/_files/order_express_with_invoice_and_shipping.php
+     * @magentoConfigFixture current_store payment/paypal_express/active 1
+     * @magentoConfigFixture current_store paypal/general/merchant_country US
+     */
+    public function testProcessIpnRequestFullRefundConcurrent()
+    {
+        $ipnData = require __DIR__ . '/../_files/ipn_refund.php';
+        $ipnFactory = $this->_objectManager->create(IpnFactory::class);
+        $ipnModel = $ipnFactory->create(
+            [
+                'data' => $ipnData,
+                'curlFactory' => $this->_createMockedHttpAdapter()
+            ]
+        );
+
+        $ipnModel->processIpnRequest();
+        $ipnModel->processIpnRequest();
+
+        $order = $this->_objectManager->create(Order::class);
+        $order->loadByIncrementId('100000001');
+
+        $creditmemoItems = $order->getCreditmemosCollection()->getItems();
+        $creditmemo = current($creditmemoItems);
+
+        $this->assertEquals(Order::STATE_CLOSED, $order->getState()) ;
+        $this->assertCount(1, $creditmemoItems);
+        $this->assertEquals(Creditmemo::STATE_REFUNDED, $creditmemo->getState());
+        $this->assertEquals(10, $order->getSubtotalRefunded());
+        $this->assertEquals(10, $order->getBaseSubtotalRefunded());
+        $this->assertEquals(20, $order->getShippingRefunded());
+        $this->assertEquals(20, $order->getBaseShippingRefunded());
+        $this->assertEquals(30, $order->getTotalRefunded());
+        $this->assertEquals(30, $order->getBaseTotalRefunded());
+        $this->assertEquals(30, $order->getTotalOnlineRefunded());
+        $this->assertEmpty($order->getTotalOfflineRefunded());
+    }
+
     /**
      * Partial refund of order amount by Paypal Express IPN message service.
      *
@@ -253,11 +293,11 @@ protected function _createMockedHttpAdapter()
         $factory = $this->createPartialMock(\Magento\Framework\HTTP\Adapter\CurlFactory::class, ['create']);
         $adapter = $this->createPartialMock(\Magento\Framework\HTTP\Adapter\Curl::class, ['read', 'write']);
 
-        $adapter->expects($this->once())->method('read')->with()->willReturn("\nVERIFIED");
+        $adapter->expects($this->any())->method('read')->with()->willReturn("\nVERIFIED");
 
-        $adapter->expects($this->once())->method('write');
+        $adapter->expects($this->any())->method('write');
 
-        $factory->expects($this->once())->method('create')->with()->willReturn($adapter);
+        $factory->expects($this->any())->method('create')->with()->willReturn($adapter);
         return $factory;
     }