From 7d88e532c9fbb9bc986f5797b58719fbc8dc0aa7 Mon Sep 17 00:00:00 2001
From: Kijin Sung <kijin@kijinsung.com>
Date: Mon, 1 May 2023 02:59:45 +0900
Subject: [PATCH] Fix deprecation warning in PHP 8.2 when $output is null

---
 classes/display/DisplayHandler.class.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/classes/display/DisplayHandler.class.php b/classes/display/DisplayHandler.class.php
index f71a7fd50..47c9ac5d3 100644
--- a/classes/display/DisplayHandler.class.php
+++ b/classes/display/DisplayHandler.class.php
@@ -182,6 +182,10 @@ class DisplayHandler extends Handler
 		{
 			return;
 		}
+		if ($output === null)
+		{
+			$output = '';
+		}
 
 		// Print debug information.
 		$debug_output = '';