From 695ec61fc9eedf2936009d9b17cc5a79c701e624 Mon Sep 17 00:00:00 2001
From: Dobes Vandermeer <dobesv@gmail.com>
Date: Fri, 2 Oct 2020 00:49:37 -0700
Subject: [PATCH] Add null check for 2d context in CanvasView

---
 src/view/CanvasView.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/view/CanvasView.js b/src/view/CanvasView.js
index ae804aadab..deade3f0e7 100644
--- a/src/view/CanvasView.js
+++ b/src/view/CanvasView.js
@@ -43,6 +43,10 @@ var CanvasView = View.extend(/** @lends CanvasView# */{
             canvas = CanvasProvider.getCanvas(size);
         }
         var ctx = this._context = canvas.getContext('2d');
+        if (!ctx) {
+            throw new Error('Canvas ' + canvas +
+                ' is unable to provide a 2D context.');
+        }
         // Save context right away, and restore in #remove(). Also restore() and
         // save() again in _setElementSize() to prevent accumulation of scaling.
         ctx.save();