微信支付时，还没有实施反馈说不能支付，金额、支付信息不对称的情况。

后端再收到微信回调的时候，err显示商户订单号重复；但支付状态显示支付完成；部分回调信息如下：

{"nonce_str":"500458624301268992","trade_state":"SUCCESS","coupon_count":"1","coupon_fee_0":"100","coupon_fee_1":"300","err_code":"INVALID_REQUEST","return_msg":"OK","err_code_des":"201 商户订单号重复","fee_type":"CNY","mch_id":"1511949901","sub_mch_id":"1603088626","coupon_id_0":"20065306632","cash_fee":"50000","coupon_id_1":"19535018332","prepay_id":"wx2810144232038735b506198489f04b0000","trade_state_desc":"支付成功","out_trade_no":"804292639217164289","coupon_fee":"100","trade_type":"JSAPI","result_code":"SUCCESS","error_code":"100","is_subscribe":"N","return_code":"SUCCESS"}