From 97fdff34b222253e0b76763f883a1439dd89d6ce Mon Sep 17 00:00:00 2001
From: "DESKTOP-49I29QK\\zsmj1" <dailer@fanruan.com>
Date: Sun, 11 Mar 2018 16:49:26 +0800
Subject: [PATCH] file.js update

---
 src/base/single/input/file.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/base/single/input/file.js b/src/base/single/input/file.js
index cbb06e50d2..75cc61ab8e 100644
--- a/src/base/single/input/file.js
+++ b/src/base/single/input/file.js
@@ -214,7 +214,9 @@
                                 break;
                         }
                     };
-                    upload.onloadstart();
+                    if (isFunction(upload.onloadstart)) {
+                        upload.onloadstart();
+                    }
                 }
                 var boundary = "AjaxUploadBoundary" + (new Date).getTime();
                 xhr.setRequestHeader("Content-Type", "multipart/form-data; boundary=" + boundary);