Repetitive sub<->leave requests on same topic results in some leave requests with no response about chat

[dilshansdoq]

In server side logs, see this log.
topic.remSession not found at all usrtq6SdhZjOJQ tq6SdhZjOJQ E3u63uhk68M iul__liJc-4DD topic.handleLeaveRequest nil pssd &{Id:a897060c-45ed-4af1-987a-b7a90f80ae90 Topic:me Unsub:false}

Here is the piece of code from where this log came.

func (t *Topic) remSession(sess *Session, asUid types.Uid) (*perSessionData, bool) {
	s := sess
	if sess.multi != nil {
		s = s.multi
	}
	pssd, ok := t.sessions[s]
	if !ok {
		fmt.Printf("topic.remSession not found at all %s %s %s %s", t.name, asUid, s.sid, s.uid)
		// Session not found at all.
		return nil, false
	}

	if pssd.uid == asUid || asUid.IsZero() {
		delete(t.sessions, s)
		return &pssd, true
	}

	for i := range pssd.muids {
		if pssd.muids[i] == asUid {
			pssd.muids[i] = pssd.muids[len(pssd.muids)-1]
			pssd.muids = pssd.muids[:len(pssd.muids)-1]
			t.sessions[s] = pssd
			if len(pssd.muids) == 0 {
				delete(t.sessions, s)
				return &pssd, true
			}

			return &pssd, false
		}
	}

	return nil, false
}

So somehow this leave request was able to bypass earlier checks set on if session was found or not.

A simple fix would be to just sent NotJoined error if session not found.

// handleLeaveRequest processes a session leave request.
func (t *Topic) handleLeaveRequest(msg *ClientComMessage, sess *Session) {
	-------

	if t.isInactive() {
	}

	// User wants to leave and unsubscribe.
	if msg.init && msg.Leave.Unsub {
	}

	// User wants to leave without unsubscribing.
	if pssd, _ := t.remSession(sess, asUid); pssd != nil {
		-----------
	} else {
		fmt.Printf("DD topic.handleLeaveRequest nil pssd %+v\n", msg.Leave)
		sess.queueOut(InfoNotJoined(msg.Id, msg.Original, msg.Timestamp))
	}
}

If this looks good, let me know.

[or-else]

Can you reproduce the problem with the latest Tinode server? I think something like this was fixed recently.

[dilshansdoq]

Yes, it has been fixed. 2f632ec
Thanks.