From 90e1cf8f5e7eb78334a5392e6788f9e1eb2440b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrg=20Lehni?= <juerg@scratchdisk.com>
Date: Sat, 30 Jan 2016 16:51:43 +0100
Subject: [PATCH] Canvas: Throw an error if a canvas cannot provide a 2D
 context.

---
 src/canvas/CanvasProvider.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/canvas/CanvasProvider.js b/src/canvas/CanvasProvider.js
index e5505cf2..715899aa 100644
--- a/src/canvas/CanvasProvider.js
+++ b/src/canvas/CanvasProvider.js
@@ -29,6 +29,10 @@ var CanvasProvider = {
             clear = false; // It's already cleared through createElement().
         }
         var ctx = canvas.getContext('2d');
+        if (!ctx) {
+            throw new Error('Canvas ' + canvas +
+                    ' is unable toprovide a 2D context.');
+        }
         // If they are not the same size, we don't need to clear them
         // using clearRect and visa versa.
         if (canvas.width === width && canvas.height === height) {