From f60cb9a5153a96296316ac7e82dde31b236a7a24 Mon Sep 17 00:00:00 2001
From: Markus Frosch <markus.frosch@icinga.com>
Date: Thu, 21 Mar 2019 13:17:19 +0100
Subject: [PATCH] ConfigHelper: Ensure empty strings are written out quoted

In renderStringWithVariables()
---
 library/Director/IcingaConfig/IcingaConfigHelper.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/library/Director/IcingaConfig/IcingaConfigHelper.php b/library/Director/IcingaConfig/IcingaConfigHelper.php
index 40ea5862..ed9f6af7 100644
--- a/library/Director/IcingaConfig/IcingaConfigHelper.php
+++ b/library/Director/IcingaConfig/IcingaConfigHelper.php
@@ -406,6 +406,10 @@ class IcingaConfigHelper
             $parts[] = static::renderString(substr($string, $offset, $i - $offset));
         }
 
-        return implode(' + ', $parts);
+        if (! empty($parts)) {
+            return implode(' + ', $parts);
+        } else {
+            return '""';
+        }
     }
 }