From 794b1f0617149873cea388e1daac0d3efc855660 Mon Sep 17 00:00:00 2001
From: CPPAlien <creaspan@gmail.com>
Date: Wed, 23 Jan 2019 10:46:09 +0800
Subject: [PATCH] fix #89

---
 lib/gradient.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/gradient.js b/lib/gradient.js
index 9252523..77daed2 100644
--- a/lib/gradient.js
+++ b/lib/gradient.js
@@ -7,7 +7,7 @@
 
   var api = {
     isGradient: function(bg) {
-      if (bg.startsWith('linear') || bg.startsWith('radial')) {
+      if (bg && (bg.startsWith('linear') || bg.startsWith('radial'))) {
         return true;
       } 
       return false;