From a55f76bf4fc729175d8909baa71bfb19a585b802 Mon Sep 17 00:00:00 2001
From: Chris Wilkinson <c.wilkinson@elifesciences.org>
Date: Fri, 5 Oct 2018 07:46:05 +0100
Subject: [PATCH] Make sure twig_include returns a string

---
 lib/Twig/Extension/Core.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Twig/Extension/Core.php b/lib/Twig/Extension/Core.php
index c3ccd54d0..9d408e178 100644
--- a/lib/Twig/Extension/Core.php
+++ b/lib/Twig/Extension/Core.php
@@ -1527,7 +1527,7 @@ function twig_include(Twig_Environment $env, $context, $template, $variables = a
         }
     }
 
-    $result = null;
+    $result = '';
     try {
         $result = $env->resolveTemplate($template)->render($variables);
     } catch (Twig_Error_Loader $e) {