Fixed #3538

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Release Notes for Craft Commerce
 
+# Unreleased
+
+- Fixed a PHP error that could occur when saving a discount. ([#3538](https://github.com/craftcms/commerce/issues/3538)) 
+
 ## 5.0.9 - 2024-06-05
 
 - Product Title fields are no longer shown when “Show the Title field” is disabled and there’s a validation error on the `title` attribute. ([craftcms/cms#13876](https://github.com/craftcms/cms/issues/13876))

src/elements/conditions/orders/DiscountOrderCondition.php

@@ -17,6 +17,25 @@ class DiscountOrderCondition extends OrderCondition implements HasStoreInterface
 {
     use StoreTrait;
 
+    /**
+     * @inheritdoc
+     */
+    protected function defineRules(): array
+    {
+        $rules = parent::defineRules();
+        $rules[] = [['storeId'], 'safe'];
+
+        return $rules;
+    }
+
+    /**
+     * @return array
+     */
+    protected function config(): array
+    {
+        return array_merge(parent::config(), $this->toArray(['storeId']));
+    }
+
     /**
      * @inheritdoc
      */