From 547ed7685a7b87b7b960380d9bcdcf21b8288247 Mon Sep 17 00:00:00 2001
From: Thomas Maier <post@webzunft.de>
Date: Wed, 9 Dec 2015 10:49:37 +0100
Subject: [PATCH] fix error log when HTTP_USER_AGENT is missing

HTTP_USER_AGENT is not always set, which causes an entry in the error log file, if WP_DEBUG is enabled.
---
 util/crayon_util.class.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/util/crayon_util.class.php b/util/crayon_util.class.php
index ca4790fe..512ffda4 100644
--- a/util/crayon_util.class.php
+++ b/util/crayon_util.class.php
@@ -790,7 +790,7 @@ public static function preg_escape_back($string) {
 
     // Detect if on a Mac or PC
     public static function is_mac($default = FALSE) {
-        $user = $_SERVER['HTTP_USER_AGENT'];
+        $user = isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT'] : '';
         if (stripos($user, 'macintosh') !== FALSE) {
             return TRUE;
         } else if (stripos($user, 'windows') !== FALSE || stripos($user, 'linux') !== FALSE) {