From 941b6a1453c513580e3979db00d786143f871413 Mon Sep 17 00:00:00 2001
From: Duncan <github.com@cricalix.net>
Date: Wed, 27 Jul 2022 08:10:32 +0100
Subject: [PATCH] Fix PHP warnings in storage_init

Fixes `PHP Warning:  Undefined array key "fetch_headers" in /usr/share/roundcube/plugins/message_highlight/message_highlight.php on line 52`
---
 message_highlight.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/message_highlight.php b/message_highlight.php
index b49189a..1584cfd 100644
--- a/message_highlight.php
+++ b/message_highlight.php
@@ -49,7 +49,7 @@ public function init()
    */
   function storage_init($p)
   {
-    $p['fetch_headers'] .= trim($p['fetch_headers']. ' ' . 'CC');
+    $p['fetch_headers'] = trim(($p['fetch_headers'] ?? '') . ' ' . 'CC');
     return($p);
   }