[5.x] Adjustments being dropped on payment

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Fixed a bug where inactive carts’ search index rows weren’t being purged. ([#4344](https://github.com/craftcms/commerce/issues/4344))
 - Fixed a bug where a transfer field layout would delete the order field layout. ([#4345](https://github.com/craftcms/commerce/issues/4345))
 - Fixed a bug where generating a PDF or cart-load URL from a console request returned a blank URL. ([#4343](https://github.com/craftcms/commerce/pull/4343))
+- Fixed a bug where completed orders could unintentionally have their recalculation mode set to "all". ([#4342](https://github.com/craftcms/commerce/issues/4342))
 - Fixed [low-severity](https://github.com/craftcms/cms/security/policy#severity--remediation) business logic vulnerability. (GHSA-gcqr-xrx9-grcf)
 
 ## 5.7.1 - 2026-07-22

src/elements/Order.php

@@ -1782,8 +1782,11 @@ public function updateOrderPaidInformation(): void
             $this->trigger(self::EVENT_AFTER_ORDER_AUTHORIZED);
         }
 
-        // restore recalculation lock state
-        $this->setRecalculationMode($originalRecalculationMode);
+        // Restore the original recalculation mode, unless this call completed the order
+        // a completed order must stay locked at `RECALCULATION_MODE_NONE` rather than reverting to its cart mode.
+        if (!$this->isCompleted) {
+            $this->setRecalculationMode($originalRecalculationMode);
+        }
     }
 
     /**

tests/unit/adjusters/ShippingTest.php

@@ -0,0 +1,115 @@
+<?php
+/**
+ * @link https://craftcms.com/
+ * @copyright Copyright (c) Pixel & Tonic, Inc.
+ * @license https://craftcms.github.io/license/
+ */
+
+namespace craftcommercetests\unit\adjusters;
+
+use Codeception\Test\Unit;
+use craft\base\Event;
+use craft\commerce\adjusters\Shipping;
+use craft\commerce\elements\Order;
+use craft\commerce\events\RegisterAvailableShippingMethodsEvent;
+use craft\commerce\models\LineItem;
+use craft\commerce\models\ShippingMethod;
+use craft\commerce\services\ShippingMethods;
+use UnitTester;
+
+/**
+ * ShippingTest
+ *
+ * @author Pixel & Tonic, Inc. <support@pixelandtonic.com>
+ */
+class ShippingTest extends Unit
+{
+    /**
+     * @var UnitTester
+     */
+    protected UnitTester $tester;
+
+    /**
+     * Toggled mid-test to simulate the registration handler matching the
+     * order, then failing to on a later call.
+     *
+     * @var bool
+     */
+    private bool $_thirdPartyMethodMatches = true;
+
+    /**
+     * @inheritdoc
+     */
+    protected function _before(): void
+    {
+        parent::_before();
+
+        $this->_thirdPartyMethodMatches = true;
+
+        // Simulate a third-party plugin registering a shipping method by
+        // re-evaluating live availability on every call, instead of
+        // returning a static, persisted method.
+        Event::on(
+            ShippingMethods::class,
+            ShippingMethods::EVENT_REGISTER_AVAILABLE_SHIPPING_METHODS,
+            function(RegisterAvailableShippingMethodsEvent $event) {
+                $shippingMethods = $event->getShippingMethods();
+                $shippingMethods->push($this->make(ShippingMethod::class, [
+                    // Plugins must set this themselves on methods they register -
+                    // `Order::getAvailableShippingMethodOptions()` silently drops any
+                    // `ShippingMethod` whose `storeId` doesn't match the order's.
+                    'storeId' => $event->order->storeId,
+                    'handle' => 'thirdPartyFlatRate',
+                    'name' => 'Third Party Flat Rate',
+                    'getIsEnabled' => true,
+                    'getMatchingShippingRule' => fn(Order $order) => null,
+                    'getPriceForOrder' => fn(Order $order) => 8.99,
+                    'matchOrder' => fn(Order $order) => $this->_thirdPartyMethodMatches,
+                ]));
+            }
+        );
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function _after(): void
+    {
+        Event::off(ShippingMethods::class, ShippingMethods::EVENT_REGISTER_AVAILABLE_SHIPPING_METHODS);
+
+        parent::_after();
+    }
+
+    /**
+     * Confirms `Shipping::adjust()` correctly drops the adjustment (no error)
+     * when a registered method stops matching. Correct cart behaviour, and
+     * not, by itself, a bug - see
+     * {@see \craftcommercetests\unit\elements\order\OrderRecalculationTest}
+     * for the recalculation-lock bug this scenario was originally written to
+     * demonstrate.
+     */
+    public function testAdjusterDropsAdjustmentWhenMethodDoesNotMatch(): void
+    {
+        $lineItem = $this->make(LineItem::class, [
+            'id' => 1,
+            'qty' => 1,
+            'price' => 50,
+            'getIsShippable' => true,
+        ]);
+
+        $order = new Order();
+        $order->shippingMethodHandle = 'thirdPartyFlatRate';
+        $order->setLineItems([$lineItem]);
+
+        $adjuster = new Shipping();
+
+        $firstPass = $adjuster->adjust($order);
+        self::assertCount(1, $firstPass, 'Shipping adjustment should be present while the method matches.');
+        self::assertEquals(8.99, $firstPass[0]->amount);
+
+        $this->_thirdPartyMethodMatches = false;
+
+        $secondPass = $adjuster->adjust($order);
+        self::assertSame([], $secondPass, 'No adjustment, no exception - this part is expected.');
+    }
+}