From 3d5f55f8edc7aad10865edb4fb9570165cc5d81f Mon Sep 17 00:00:00 2001
From: Sebastian Serth <Sebastian.Serth@hpi.de>
Date: Fri, 17 Nov 2023 14:52:02 +0100
Subject: [PATCH] Only apply Turtle update if canvas is present

Fixes CODEOCEAN-FRONTEND-4T
---
 app/assets/javascripts/turtle.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/assets/javascripts/turtle.js b/app/assets/javascripts/turtle.js
index d475eac9..536f24a7 100644
--- a/app/assets/javascripts/turtle.js
+++ b/app/assets/javascripts/turtle.js
@@ -81,6 +81,9 @@ function Turtle(unused_pipe_reference, canvas) {
 Turtle.prototype.update = function () {
     let k, c;
     const canvas = this.canvas[0];
+    if (canvas === undefined) {
+        return;
+    }
     canvas.width = this.get_width() * devicePixelRatio;
     canvas.height = this.get_height() * devicePixelRatio;
     canvas.style.width = `${this.get_width()}px`;