From 1d54a50c31cb788bf786397ea5664bd02bfe36fb Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Mon, 4 May 2020 18:25:29 +0200
Subject: [PATCH] XMPP: autorejoin MUCs when reconnecting

---
 connector/xmpp/xmpp.go | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/connector/xmpp/xmpp.go b/connector/xmpp/xmpp.go
index 483c75e..a25a31b 100644
--- a/connector/xmpp/xmpp.go
+++ b/connector/xmpp/xmpp.go
@@ -35,7 +35,8 @@ type XMPP struct {
 
 	conn *gxmpp.Client
 
-	isMUC map[string]bool
+	isMUC     map[string]bool
+	joinedMUC map[string]bool
 }
 
 func (xm *XMPP) SetHandler(h Handler) {
@@ -86,6 +87,7 @@ func (xm *XMPP) Configure(c Configuration) error {
 	if xm.isMUC == nil {
 		xm.isMUC = make(map[string]bool)
 	}
+	xm.joinedMUC = make(map[string]bool)
 
 	xm.connectorLoopNum += 1
 	go xm.connectLoop(xm.connectorLoopNum)
@@ -106,7 +108,7 @@ func (xm *XMPP) connectLoop(num int) {
 			return
 		}
 		tc := &tls.Config{
-			ServerName:         strings.Split(xm.jid, "@")[1],
+			ServerName:         xm.server,
 			InsecureSkipVerify: true,
 		}
 		options := gxmpp.Options{
@@ -132,12 +134,23 @@ func (xm *XMPP) connectLoop(num int) {
 		} else {
 			xm.connected = true
 			xm.timeout = 10
-			err = xm.handleXMPP()
-			if err != nil {
-				xm.connected = false
-				log.Debugf("XMPP disconnected: %s\n", err)
-				log.Debugf("Reconnecting.\n")
+
+			for muc, joined := range xm.joinedMUC {
+				if joined {
+					_, err := xm.conn.JoinMUCNoHistory(muc, xm.nickname)
+					if err != nil {
+						log.Warnf("Could not rejoin MUC %s after reconnection: %s", muc, err)
+						xm.handler.Left(RoomID(muc))
+						delete(xm.joinedMUC, muc)
+					}
+				}
 			}
+
+			err = xm.handleXMPP()
+
+			xm.connected = false
+			log.Debugf("XMPP disconnected: %s\n", err)
+			log.Debugf("Reconnecting.\n")
 		}
 	}
 }
@@ -289,6 +302,11 @@ func (xm *XMPP) Join(roomId RoomID) error {
 
 	log.Tracef("Join %s with nick %s\n", roomId, xm.nickname)
 	_, err := xm.conn.JoinMUCNoHistory(string(roomId), xm.nickname)
+
+	if err == nil {
+		xm.joinedMUC[string(roomId)] = true
+	}
+
 	return err
 }
 
@@ -304,6 +322,7 @@ func (xm *XMPP) Invite(userId UserID, roomId RoomID) error {
 
 func (xm *XMPP) Leave(roomId RoomID) {
 	xm.conn.LeaveMUC(string(roomId))
+	delete(xm.joinedMUC, string(roomId))
 }
 
 func (xm *XMPP) SearchForUsers(query string) ([]UserSearchResult, error) {