From 01100c9a4aa8aa3e32b51370c6c11acb0e5e44aa Mon Sep 17 00:00:00 2001
From: Ryan Lieu <github-benzBrake@woai.ru>
Date: Fri, 14 Apr 2023 11:45:09 +0800
Subject: [PATCH] Fix: php 8.1 strtolower not allow null value (#1559)

---
 var/Widget/Archive.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/var/Widget/Archive.php b/var/Widget/Archive.php
index 1ee9d39b..22dd29fe 100644
--- a/var/Widget/Archive.php
+++ b/var/Widget/Archive.php
@@ -1032,7 +1032,7 @@ class Archive extends Contents
      */
     public function related(int $limit = 5, ?string $type = null): Contents
     {
-        $type = strtolower($type);
+        $type = strtolower($type ?? '');
 
         switch ($type) {
             case 'author':