From bfa9972d7fe9ab66967868ed4fccbaea00931735 Mon Sep 17 00:00:00 2001
From: Barry Pollard <barry_pollard@hotmail.com>
Date: Wed, 15 Apr 2020 21:05:38 +0100
Subject: [PATCH] Add test for index (#734)

---
 src/static/js/chapter.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/static/js/chapter.js b/src/static/js/chapter.js
index 0840178e84e..b4dcf1c9a0c 100644
--- a/src/static/js/chapter.js
+++ b/src/static/js/chapter.js
@@ -265,6 +265,11 @@ function indexHighlighter() {
 
   var chapterIndex = document.querySelector('.index-box');
 
+  // If not index - then nothing to do!
+  if (!chapterIndex) {
+    return;
+  }
+
   // Check if user has set reduced motion and only continue if not
   var hasOSReducedMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
   if (hasOSReducedMotion) {