Fix metronome + capture alignment for Mixbus

libs/ardour/diskstream.cc

@@ -266,6 +266,15 @@ Diskstream::set_capture_offset ()
 	switch (_alignment_style) {
 	case ExistingMaterial:
 		_capture_offset = _io->latency();
+#ifdef MIXBUS
+		/* add additional latency, delayline inside the channelstrip + master-bus
+		 * in MB the master-bus has no input-ports, so its latency does not propagate
+		 */
+		if (_session.master_out()) {
+			_capture_offset += _session.master_out()->signal_latency();
+		}
+#endif
+
 		break;
 
 	case CaptureTime:

libs/ardour/session_click.cc

@@ -80,6 +80,11 @@ Session::click (framepos_t start, framecnt_t nframes)
 	}
 
 	start -= _worst_track_latency;
+#ifdef MIXBUS
+	if (_master_out) {
+		start -= _master_out->signal_latency (); // delay signal by mixbus' internal latency
+	}
+#endif
 	/* start could be negative at this point */
 	const framepos_t end = start + nframes;
 	/* correct start, potentially */