From 9ed61ff32b0120a933970a0c5bfaf1de1aa7d9b4 Mon Sep 17 00:00:00 2001
From: Daniel Lienert <daniel@lienert.cc>
Date: Thu, 5 Mar 2020 21:21:26 +0100
Subject: [PATCH] BUGFIX: Do not fail when null is given

---
 Classes/Eel/ArchivistHelper.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Classes/Eel/ArchivistHelper.php b/Classes/Eel/ArchivistHelper.php
index 95ccb1f..25e26ab 100644
--- a/Classes/Eel/ArchivistHelper.php
+++ b/Classes/Eel/ArchivistHelper.php
@@ -25,6 +25,10 @@ class ArchivistHelper implements ProtectedContextAwareInterface
      */
     public function buildSortingCharacter(?string $string, int $position = 0, int $length = 1): string
     {
+        if ($string === null) {
+            return '#';
+        }
+
         $character = mb_substr($string, $position, $length);
 
         // Transliterate (transform 北京 to 'Bei Jing')