Detect sequence gaps in local audio integration

gumble/gumble/integration_audio_test.go

@@ -73,15 +73,23 @@ func TestLocalMumbleAudioRoundTrip(t *testing.T) {
 	}
 	// Discard the first few decoder warm-up frames before measuring pitch.
 	var packet *gumble.AudioPacket
+	var previousSequence int64
 	for i := 0; i < 3; i++ {
 		select {
 		case packet = <-listener.packets:
+			if i > 0 && packet.Sequence != previousSequence+1 {
+				t.Fatalf("choppy relay: sequence gap %d -> %d", previousSequence, packet.Sequence)
+			}
+			previousSequence = packet.Sequence
 		case <-time.After(8 * time.Second):
 			t.Fatal("timed out waiting for relayed audio")
 		}
 	}
 	select {
 	case packet = <-listener.packets:
+		if packet.Sequence != previousSequence+1 {
+			t.Fatalf("choppy relay: sequence gap %d -> %d", previousSequence, packet.Sequence)
+		}
 		frequency, purity, peak := audioQuality(packet.AudioBuffer)
 		if peak < 500 {
 			t.Fatalf("received silent audio peak=%d", peak)