From 291b9957ad722179deca738703725487a38eba1e Mon Sep 17 00:00:00 2001
From: Hannes Papenberg <info@joomlager.de>
Date: Tue, 17 Oct 2023 22:15:03 +0200
Subject: [PATCH] [5.0] MailTemplate: Prevent notice in replaceTags (#41679)

* MailTemplate: Prevent notice in replaceTags

* Update libraries/src/Mail/MailTemplate.php

Co-authored-by: Quy <quy@nomonkeybiz.com>

* Update MailTemplate.php

---------

Co-authored-by: Quy <quy@nomonkeybiz.com>
---
 libraries/src/Mail/MailTemplate.php | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libraries/src/Mail/MailTemplate.php b/libraries/src/Mail/MailTemplate.php
index 605c44339d07d..b74c2b67d17f5 100644
--- a/libraries/src/Mail/MailTemplate.php
+++ b/libraries/src/Mail/MailTemplate.php
@@ -325,6 +325,11 @@ public function send()
     protected function replaceTags($text, $tags)
     {
         foreach ($tags as $key => $value) {
+            // If the value is NULL, replace with an empty string. NULL itself throws notices
+            if (\is_null($value)) {
+                $value = '';
+            }
+
             if (\is_array($value)) {
                 $matches = [];
                 $pregKey = preg_quote(strtoupper($key), '/');