From caaa72b7529f09311a489c06c2df22d508701014 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bar=C4=B1=C5=9F=20Soner=20U=C5=9Fakl=C4=B1?=
 <baris@nodebb.org>
Date: Mon, 27 Nov 2017 12:52:08 -0500
Subject: [PATCH] closes #6124

---
 src/user/profile.js |  5 ++++-
 test/user.js        | 13 +++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/user/profile.js b/src/user/profile.js
index 70dffeebe6..ae1e31c475 100644
--- a/src/user/profile.js
+++ b/src/user/profile.js
@@ -196,7 +196,7 @@ module.exports = function (User) {
 
 	function updateUsername(uid, newUsername, callback) {
 		if (!newUsername) {
-			return callback();
+			return setImmediate(callback);
 		}
 
 		async.waterfall([
@@ -204,6 +204,9 @@ module.exports = function (User) {
 				User.getUserFields(uid, ['username', 'userslug'], next);
 			},
 			function (userData, next) {
+				if (userData.username === newUsername) {
+					return callback();
+				}
 				async.parallel([
 					function (next) {
 						updateUidMapping('username', uid, newUsername, userData.username, next);
diff --git a/test/user.js b/test/user.js
index 0decbfe0f6..0db0b69840 100644
--- a/test/user.js
+++ b/test/user.js
@@ -627,6 +627,19 @@ describe('User', function () {
 			});
 		});
 
+		it('should not update a user\'s username if it did not change', function (done) {
+			socketUser.changeUsernameEmail({ uid: uid }, { uid: uid, username: 'updatedAgain', password: '123456' }, function (err) {
+				assert.ifError(err);
+				db.getSortedSetRevRange('user:' + uid + ':usernames', 0, -1, function (err, data) {
+					assert.ifError(err);
+					console.log(data);
+					assert(data[0].startsWith('updatedAgain'));
+					assert(data[1].startsWith('updatedUserName'));
+					done();
+				});
+			});
+		});
+
 		it('should change email', function (done) {
 			socketUser.changeUsernameEmail({ uid: uid }, { uid: uid, email: 'updatedAgain@me.com', password: '123456' }, function (err) {
 				assert.ifError(err);