From 73a8d593bb8efde53409f6d9054b06b23b610bbd Mon Sep 17 00:00:00 2001
From: John McLear <john@mclear.co.uk>
Date: Sat, 2 Oct 2021 15:08:14 +0100
Subject: [PATCH] bugfix: only try to go to a line if the line actually exists

---
 src/static/js/broadcast.js | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/static/js/broadcast.js b/src/static/js/broadcast.js
index 909b6a085..93b80dac3 100644
--- a/src/static/js/broadcast.js
+++ b/src/static/js/broadcast.js
@@ -173,13 +173,15 @@ const loadBroadcastJS = (socket, sendSocketMsg, fireWhenAllScriptsAreLoaded, Bro
       const goToLineNumber = (lineNumber) => {
         // Sets the Y scrolling of the browser to go to this line
         const line = $('#innerdocbody').find(`div:nth-child(${lineNumber + 1})`);
-        const newY = $(line)[0].offsetTop;
-        const ecb = document.getElementById('editorcontainerbox');
-        // Chrome 55 - 59 bugfix
-        if (ecb.scrollTo) {
-          ecb.scrollTo({top: newY, behavior: 'auto'});
-        } else {
-          $('#editorcontainerbox').scrollTop(newY);
+        if (line) {
+          const newY = $(line)[0].offsetTop;
+          const ecb = document.getElementById('editorcontainerbox');
+          // Chrome 55 - 59 bugfix
+          if (ecb.scrollTo) {
+            ecb.scrollTo({top: newY, behavior: 'auto'});
+          } else {
+            $('#editorcontainerbox').scrollTop(newY);
+          }
         }
       };