Merge pull request #4071 from craftcms/nathaniel/pt-2840-5x-twig-runtimeerror-couponhiddeninputs-called-when-editing

[5.x] Fix #4069 edit discounts PHP error

Author: nfourtythree

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Fixed a PHP error that could occur when viewing variant indexes and using Craft CMS 5.6.17 or earlier. ([#4060](https://github.com/craftcms/commerce/issues/4060))
 - Fixed a bug where currency based order condition rules incorrectly showed up as custom fields.
 - Fixed a bug where Subscription and Transfer elements’ field layouts were not deleted when Commerce was uninstalled.
+- Fixed a PHP error that could occur when editing discounts. ([#4069](https://github.com/craftcms/commerce/issues/4069))
 
 ## 5.4.0 - 2025-06-23
 

src/controllers/DiscountsController.php

@@ -227,6 +227,10 @@ public function actionEdit(int $id = null, Discount $discount = null, string $st
         $variables['percentSymbol'] = Craft::$app->getFormattingLocale()->getNumberSymbol(Locale::SYMBOL_PERCENT);
         $this->getView()->registerAssetBundle(CouponsAsset::class);
 
+        $variables['coupons'] = collect($variables['discount']->getCoupons())
+            ->map(fn(Coupon $coupon) => $coupon->toArray())
+            ->all();
+
         return $this->renderTemplate('commerce/store-management/discounts/_edit', $variables);
     }
 

src/templates/store-management/discounts/_edit.twig

@@ -269,7 +269,7 @@
                             id: 'commerce-coupons-table',
                             name: couponsTable.name,
                             cols: couponsTable.cols,
-                            rows: discount.coupons,
+                            rows: coupons,
                             addRowLabel: 'Add a coupon'|t('commerce'),
                             allowAdd: true,
                             allowDelete: true,