Fix join and part/leave on replay

Without this, on matterircd reconnect & relay, users in channels can
be out of sync. This causes issues with trying to auto-complete IRC
nicks for example.

Author: hloeung

mm-go-irckit/channel.go

@@ -162,14 +162,17 @@ func (ch *channel) Part(u *User, text string) {
 
 	if _, ok := ch.usersIdx[u.ID()]; !ok {
 		ch.mu.Unlock()
-
+		for _, to := range ch.usersIdx {
+			if !to.Ghost {
+				to.Encode(msg)
+			}
+		}
 		u.Encode(&irc.Message{
 			Prefix:   ch.Prefix(),
 			Command:  irc.ERR_NOTONCHANNEL,
 			Params:   []string{ch.name},
-			Trailing: "You're not on that channel",
+			Trailing: "User not on that channel",
 		})
-
 		return
 	}
 
@@ -335,8 +338,20 @@ func (ch *channel) Join(u *User) error {
 		return nil
 	}
 
+	msg := &irc.Message{
+		Prefix:  u.Prefix(),
+		Command: irc.JOIN,
+		Params:  []string{ch.name},
+	}
+
 	if _, exists := ch.usersIdx[u.ID()]; exists {
 		ch.mu.Unlock()
+		for _, to := range ch.usersIdx {
+			// only send join messages to real users
+			if !to.Ghost {
+				to.Encode(msg)
+			}
+		}
 		return nil
 	}
 
@@ -354,12 +369,6 @@ func (ch *channel) Join(u *User) error {
 		return nil
 	}
 
-	msg := &irc.Message{
-		Prefix:  u.Prefix(),
-		Command: irc.JOIN,
-		Params:  []string{ch.name},
-	}
-
 	// send regular users a notification of the join
 	ch.mu.RLock()
 

mm-go-irckit/userbridge.go

@@ -698,9 +698,6 @@ func (u *User) addUserToChannelWorker(channels <-chan *bridge.ChannelInfo, throt
 		// traverse the order in reverse
 		for i := len(mmPostList.Order) - 1; i >= 0; i-- {
 			p := mmPostList.Posts[mmPostList.Order[i]]
-			if p.Type == model.PostTypeJoinLeave {
-				continue
-			}
 
 			if p.DeleteAt > p.CreateAt {
 				continue
@@ -725,8 +722,31 @@ func (u *User) addUserToChannelWorker(channels <-chan *bridge.ChannelInfo, throt
 				nick = botname
 			}
 
-			if p.Type == model.PostTypeAddToTeam || p.Type == model.PostTypeRemoveFromTeam {
+			switch {
+			case p.Type == model.PostTypeAddToTeam:
+				nick = systemUser
+				ghost := u.createUserFromInfo(user)
+				u.Srv.Channel(brchannel.ID).Join(ghost) //nolint:errcheck
+			case p.Type == model.PostTypeRemoveFromTeam:
 				nick = systemUser
+				ghost := u.createUserFromInfo(user)
+				u.Srv.Channel(brchannel.ID).Part(ghost, "") //nolint:errcheck
+			case p.Type == model.PostTypeJoinChannel:
+				ghost := u.createUserFromInfo(user)
+				u.Srv.Channel(brchannel.ID).Join(ghost) //nolint:errcheck
+			case p.Type == model.PostTypeLeaveChannel:
+				ghost := u.createUserFromInfo(user)
+				u.Srv.Channel(brchannel.ID).Part(ghost, "") //nolint:errcheck
+			case p.Type == model.PostTypeAddToChannel:
+				if addedUserId, ok := props["addedUserId"].(string); ok {
+					ghost := u.createUserFromInfo(u.br.GetUser(addedUserId))
+					u.Srv.Channel(brchannel.ID).Join(ghost) //nolint:errcheck
+				}
+			case p.Type == model.PostTypeRemoveFromChannel:
+				if removedUserId, ok := props["removedUserId"].(string); ok {
+					ghost := u.createUserFromInfo(u.br.GetUser(removedUserId))
+					u.Srv.Channel(brchannel.ID).Part(ghost, "") //nolint:errcheck
+				}
 			}
 
 			for _, post := range strings.Split(p.Message, "\n") {