Send unpublished callback unconditionally. (#1418)

Even if an add track has been queued and can be used immediately
when the previous incarnation unpublishes, send the unpublished
callback as the track was technically unpublished and republished.
The re-publish will pick the same track SID when the pending track
is queued as it will get the SID from an existing published track.

pkg/rtc/participant.go

@@ -1638,18 +1638,16 @@ func (p *ParticipantImpl) addMediaTrack(signalCid string, sdpCid string, ti *liv
 			!p.IsClosed(),
 		)
 
-		isUnpublished := false
 		// re-use Track sid
 		p.pendingTracksLock.Lock()
 		if pti := p.pendingTracks[signalCid]; pti != nil {
 			p.sendTrackPublished(signalCid, pti.trackInfos[0])
 		} else {
 			p.unpublishedTracks = append(p.unpublishedTracks, ti)
-			isUnpublished = true
 		}
 		p.pendingTracksLock.Unlock()
 
-		if isUnpublished && !p.IsClosed() {
+		if !p.IsClosed() {
 			// unpublished events aren't necessary when participant is closed
 			p.params.Logger.Debugw("unpublished track", "trackID", ti.Sid, "trackInfo", ti)
 			p.lock.RLock()

pkg/sfu/downtrack.go

@@ -795,7 +795,7 @@ func (d *DownTrack) CloseWithFlush(flush bool) {
 	d.bindLock.Unlock()
 	d.connectionStats.Close()
 	d.rtpStats.Stop()
-	d.logger.Infow("rtp stats", "direction", "downstream", "mime", d.mime, "stats", d.rtpStats.ToString())
+	d.logger.Infow("rtp stats", "direction", "downstream", "mime", d.mime, "ssrc", d.ssrc, "stats", d.rtpStats.ToString())
 
 	if d.onMaxLayerChanged != nil && d.kind == webrtc.RTPCodecTypeVideo {
 		d.onMaxLayerChanged(d, InvalidLayerSpatial)