From 8feaef045977e76363b0fac08de6da5198f56e59 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Wed, 4 Sep 2019 01:17:28 +0800
Subject: [PATCH] fix: `sortObject` should not introduce formerly non-existent
 fields

(cherry picked from commit e585fc3881d7d6830cc6cd87f30a22ec45621fab)
---
 packages/@vue/cli/lib/util/sortObject.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/@vue/cli/lib/util/sortObject.js b/packages/@vue/cli/lib/util/sortObject.js
index 7b4dd1ad74..3c4a361bf2 100644
--- a/packages/@vue/cli/lib/util/sortObject.js
+++ b/packages/@vue/cli/lib/util/sortObject.js
@@ -4,8 +4,10 @@ module.exports = function sortObject (obj, keyOrder, dontSortByUnicode) {
 
   if (keyOrder) {
     keyOrder.forEach(key => {
-      res[key] = obj[key]
-      delete obj[key]
+      if (obj.hasOwnProperty(key)) {
+        res[key] = obj[key]
+        delete obj[key]
+      }
     })
   }