update: 加入购物车或购买时，规格修改为默认全不选

（之前默认所有规格选中第一个)

view/xcx/pages/goods_details/index.js

@@ -120,7 +120,7 @@ Page({
   /**
    * 登录后加载
    * 
-  */
+   */
   onLoadFun: function (e) {
     this.setData({ isLog: true });
     this.getCouponList();
@@ -464,9 +464,10 @@ Page({
       }
     }
     for (var i = 0, len = productAttr.length; i < len; i++) {
-      if (productAttr[i].attr_value[0]) productAttr[i].checked = value[i];
+      if (productAttr[i].attr_value[0]) productAttr[i].checked = false; // value[i];
     };
     var productSelect = this.data.productValue[value.sort().join(',')];
+    productSelect = null;
     if (productSelect) {
       this.setData({
         ["productSelect.store_name"]: storeInfo.store_name,

view/xcx/pages/goods_details/index.wxml

@@ -169,7 +169,7 @@
       <form bindsubmit="joinCart">
         <button class='joinCart bnts' formType="submit">加入购物车</button>
       </form>
-      <form bindsubmit="goBuy" wx:if="{{productSelect.stock>0}}">
+      <form bindsubmit="goBuy" wx:if="{{!attrValue || productSelect.stock>0}}">
         <button class='buy bnts' formType="submit">立即购买</button>
       </form>
       <form wx:else>