From 79b381bca31f04bded15eb67c8b75fdcee4d0767 Mon Sep 17 00:00:00 2001
From: "Pierre H. Lehnen" <Hudell@users.noreply.github.com>
Date: Tue, 26 Jun 2018 09:39:09 -0300
Subject: [PATCH] Fixes an error triggered by the new users login in using CAS
 trying to subscribe to general channel twice (#11257)

---
 packages/rocketchat-cas/server/cas_server.js | 21 +++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/packages/rocketchat-cas/server/cas_server.js b/packages/rocketchat-cas/server/cas_server.js
index ca89e1f0f6a89..492700a134f36 100644
--- a/packages/rocketchat-cas/server/cas_server.js
+++ b/packages/rocketchat-cas/server/cas_server.js
@@ -231,15 +231,18 @@ Accounts.registerLoginHandler(function(options) {
 					if (!room) {
 						room = RocketChat.models.Rooms.createWithIdTypeAndName(Random.id(), 'c', room_name);
 					}
-					RocketChat.models.Rooms.addUsernameByName(room_name, result.username);
-					RocketChat.models.Subscriptions.createWithRoomAndUser(room, user, {
-						ts: new Date(),
-						open: true,
-						alert: true,
-						unread: 1,
-						userMentions: 1,
-						groupMentions: 0
-					});
+
+					if (!RocketChat.models.Subscriptions.findOneByRoomIdAndUserId(room._id, userId)) {
+						RocketChat.models.Rooms.addUsernameByName(room_name, result.username);
+						RocketChat.models.Subscriptions.createWithRoomAndUser(room, user, {
+							ts: new Date(),
+							open: true,
+							alert: true,
+							unread: 1,
+							userMentions: 1,
+							groupMentions: 0
+						});
+					}
 				}
 			});
 		}