fix #2133 (#2137)

* fix #2133

Don't record NICK and QUIT in history for invisible auditorium members

irc/channel.go

 	return
 }
 
+// returns whether the client is visible to unprivileged users in the channel
+// (i.e., respecting auditorium mode). note that this assumes that the client
+// is a member; if the client is not, it may return true anyway
+func (channel *Channel) memberIsVisible(client *Client) bool {
+	// fast path, we assume they're a member so if this isn't an auditorium,
+	// they're visible:
+	if !channel.flags.HasMode(modes.Auditorium) {
+		return true
+	}
+
+	channel.stateMutex.RLock()
+	defer channel.stateMutex.RUnlock()
+
+	clientData, found := channel.members[client]
+	if !found {
+		return false
+	}
+	return clientData.modes.HighestChannelUserMode() != modes.Mode(0)
+}
+
 // data for RPL_LIST
 func (channel *Channel) listData() (memberCount int, name, topic string) {
 	channel.stateMutex.RLock()

irc/client.go

 	}
 
 	var quitItem history.Item
-	var channels []*Channel
+	var quitHistoryChannels []*Channel
 	// use a defer here to avoid writing to mysql while holding the destroy semaphore:
 	defer func() {
-		for _, channel := range channels {
+		for _, channel := range quitHistoryChannels {
 			channel.AddHistoryItem(quitItem, details.account)
 		}
 	}()
 	// clean up channels
 	// (note that if this is a reattach, client has no channels and therefore no friends)
 	friends := make(ClientSet)
-	channels = client.Channels()
+	channels := client.Channels()
 	for _, channel := range channels {
+		if channel.memberIsVisible(client) {
+			quitHistoryChannels = append(quitHistoryChannels, channel)
+		}
 		for _, member := range channel.auditoriumFriends(client) {
 			friends.Add(member)
 		}

irc/nickname.go

 	}
 
 	for _, channel := range target.Channels() {
-		channel.AddHistoryItem(histItem, details.account)
+		if channel.memberIsVisible(client) {
+			channel.AddHistoryItem(histItem, details.account)
+		}
 	}
 
 	newCfnick := target.NickCasefolded()