From f3cc348f85a55826c2ab2aca75a49d8bbc9d4b7c Mon Sep 17 00:00:00 2001
From: Sven Reichel <github-sr@hotmail.com>
Date: Fri, 2 Sep 2022 00:22:18 +0200
Subject: [PATCH] Fixed admin grid filter

E.g. customer review: filter by customer group
---
 app/code/core/Mage/Adminhtml/Block/Widget/Grid.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/code/core/Mage/Adminhtml/Block/Widget/Grid.php b/app/code/core/Mage/Adminhtml/Block/Widget/Grid.php
index d3acfc0756a..856e34dd098 100644
--- a/app/code/core/Mage/Adminhtml/Block/Widget/Grid.php
+++ b/app/code/core/Mage/Adminhtml/Block/Widget/Grid.php
@@ -500,7 +500,7 @@ protected function _addColumnFilterToCollection($column)
                 if ($field && $cond !== null) {
                     $filtered = array_map(static function ($value) {
                         return is_object($value) ? $value->__toString() : $value;
-                    }, array_values($cond));
+                    }, is_array($cond) ? array_values($cond) : [$cond]);
                     if (in_array('\'%NULL%\'', $filtered, true) || in_array('NULL', $filtered, true)) {
                         $this->getCollection()->addFieldToFilter($field, ['null' => true]);
                     } else {