From 0c4ad03a4ed8ef603717f6c888068b73fdecf4e6 Mon Sep 17 00:00:00 2001
From: bwestpha <bwestpha@googlemail.com>
Date: Wed, 30 Mar 2016 10:45:14 +0200
Subject: [PATCH] Fixes error that causes permanently fail of chart creation

in some cases d3.event.sourceEvent is null (I don't really know why)... In my case that happens when i change thw window soze of the browser window and then zoom in charts with my infrared multitouch TV, then a exception is thrown "can't read the property of type on 'null' ". After that error is thrown (I also don't know why) its not possible to create new charts with c3.

this will fix the issue
---
 c3.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/c3.js b/c3.js
index 7033439..f1539e1 100644
--- a/c3.js
+++ b/c3.js
@@ -5700,6 +5700,9 @@
     };
     c3_chart_internal_fn.redrawForZoom = function () {
         var $$ = this, d3 = $$.d3, config = $$.config, zoom = $$.zoom, x = $$.x;
+        if(d3.event.sourceEvent == null){
+            return;
+        }
         if (!config.zoom_enabled) {
             return;
         }