退款金额不能高于订单总金额

application/admin/controller/unishop/Order.php

@@ -678,6 +678,9 @@ class Order extends Backend
             $this->error("订单已取消，请勿重复操作");
         }
         if ($order->have_paid>0){
+            if ($order['total_price']<$refund_fee) {
+                $this->error("退款金额不能高于订单总金额");
+            }
             //已支付
             self::refundOrder($order,$refund_fee);
         }else{