From 08855cd4ff2876b6455dd948129a0c2adc91352d Mon Sep 17 00:00:00 2001
From: pah100 <sushuang0322@gmail.com>
Date: Thu, 14 Jan 2016 16:03:54 +0800
Subject: [PATCH] enhance merge method and fix ec option.backgroundColor merge
 bug.

---
 src/core/util.js | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/core/util.js b/src/core/util.js
index f3ad937c5..e1e688e48 100644
--- a/src/core/util.js
+++ b/src/core/util.js
@@ -53,16 +53,15 @@ define(function(require) {
     }
 
     /**
-     * @param {Object=} target
-     * @param {Object=} source
+     * @param {*} target
+     * @param {*} source
      * @param {boolean} [overwrite=false]
      */
     function merge(target, source, overwrite) {
-        if (!target) { // Might be null/undefined
-            return;
-        }
-        if (!source) { // Might be null/undefined
-            return target;
+        // We should escapse that source is string
+        // and enter for ... in ...
+        if (!isObject(source) || !isObject(target)) {
+            return overwrite ? clone(source) : target;
         }
 
         for (var key in source) {