From 63a8e53b0866e29423ed82eafb36ea8bcc465e71 Mon Sep 17 00:00:00 2001
From: campbell-m <87438215+campbell-m@users.noreply.github.com>
Date: Wed, 17 Jul 2024 15:02:16 +0100
Subject: [PATCH] Add requirement for mbstring extension to be loaded for QR
 code to work

---
 web/Themes/default/header.inc | 6 ++++--
 web/systemdefaults.inc.php    | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/web/Themes/default/header.inc b/web/Themes/default/header.inc
index af7012a463..3e6d20f0e7 100644
--- a/web/Themes/default/header.inc
+++ b/web/Themes/default/header.inc
@@ -471,10 +471,12 @@ function print_banner(?array $context, $simple=false, $omit_login=false) : void
     echo "</nav>\n";
 
     // Add in a QR code for kiosk mode
-    // (The QR code library requires PHP 7.4 or greater)
+    // (The QR code library requires PHP 7.4 or greater and the mbstring extension)
     if (isset($context['kiosk']) &&
         $kiosk_QR_code &&
-        (version_compare(PHP_VERSION, '7.4') >= 0))
+        (version_compare(PHP_VERSION, '7.4') >= 0) &&
+        //Check for a Mbstring constant rather than using extension_loaded, which is sometimes disabled
+        defined('MB_CASE_UPPER'))
     {
       $url = multisite(url_base() . "/index.php?$query");
       echo '<nav class="qr" title="' . htmlspecialchars($url) . "\">\n";
diff --git a/web/systemdefaults.inc.php b/web/systemdefaults.inc.php
index b441ca17c3..e860d47d51 100644
--- a/web/systemdefaults.inc.php
+++ b/web/systemdefaults.inc.php
@@ -436,7 +436,7 @@
 $kiosk_default_mode = 'room';
 
 // Whether to show a QR code in kiosk mode
-// Note that PHP 7.4 or greater is required for a QR code
+// Note that PHP 7.4 or greater and the mbstring extension are required for a QR code
 $kiosk_QR_code = true;
 
 // Timeout if the exit kiosk mode dialog is not acted upon