From aa178f9e253e762e156c1206d55f4b37daf43407 Mon Sep 17 00:00:00 2001
From: Joas Schilling <coding@schilljs.com>
Date: Fri, 23 Apr 2021 10:54:45 +0200
Subject: [PATCH] Do not allow to overwrite some variables

Signed-off-by: Joas Schilling <coding@schilljs.com>
---
 lib/private/Template/Base.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/private/Template/Base.php b/lib/private/Template/Base.php
index 04d03b6e6f..856d09ad4e 100644
--- a/lib/private/Template/Base.php
+++ b/lib/private/Template/Base.php
@@ -168,7 +168,9 @@ class Base {
 		if (!is_null($additionalParams)) {
 			$_ = array_merge($additionalParams, $this->vars);
 			foreach ($_ as $var => $value) {
-				${$var} = $value;
+				if (!isset(${$var})) {
+					${$var} = $value;
+				}
 			}
 		}