allow auditioning via the monitor section to work.

Ideally, we would feed the monitor section via an internal (aux) send/return, but this is an improvement over what we had before

libs/ardour/ardour/auditioner.h

@@ -40,6 +40,7 @@ class Auditioner : public AudioTrack
 	~Auditioner ();
 
 	int init ();
+        int connect ();
 
 	void audition_region (boost::shared_ptr<Region>);
 

libs/ardour/audio_buffer.cc

@@ -88,7 +88,7 @@ AudioBuffer::check_silence (pframes_t nframes, bool wholebuffer, pframes_t& n) c
 
 void
 AudioBuffer::silence (framecnt_t len, framecnt_t offset) {
-	pframes_t n = 0;
+
 	if (!_silent) {
 		assert(_capacity > 0);
 		assert(offset + len <= _capacity);

libs/ardour/auditioner.cc

@@ -54,13 +54,31 @@ Auditioner::init ()
         if (Track::init ()) {
                 return -1;
         }
+	
+	if (connect ()) {
+		return -1;
+	}
 
+	_output->changed.connect_same_thread (*this, boost::bind (&Auditioner::output_changed, this, _1, _2));
+
+        return 0;
+}
+
+Auditioner::~Auditioner ()
+{
+}
+
+int
+Auditioner::connect ()
+{
 	string left = Config->get_auditioner_output_left();
 	string right = Config->get_auditioner_output_right();
 
 	vector<string> outputs;
 	_session.engine().get_physical_outputs (DataType::AUDIO, outputs);
 
+	via_monitor = false;
+
 	if (left.empty() || left == "default") {
                 if (_session.monitor_out()) {
                         left = _session.monitor_out()->input()->audio (0)->name();
@@ -83,31 +101,49 @@ Auditioner::init ()
                 }
 	}
 
+	_output->disconnect (this);
+
 	if (left.empty() && right.empty()) {
-		warning << _("no outputs available for auditioner - manual connection required") << endmsg;
+		if (_output->n_ports().n_audio() == 0) {
+			/* ports not set up, so must be during startup */
+			warning << _("no outputs available for auditioner - manual connection required") << endmsg;
+		}
 	} else {
 
-		_main_outs->defer_pan_reset ();
-		
-		if (left.length()) {
-			_output->add_port (left, this, DataType::AUDIO);
+		if (_output->n_ports().n_audio() == 0) {
+
+			/* create (and connect) new ports */
+
+			_main_outs->defer_pan_reset ();
+			
+			if (left.length()) {
+				_output->add_port (left, this, DataType::AUDIO);
+			}
+			
+			if (right.length()) {
+				_output->add_port (right, this, DataType::AUDIO);
+			}
+			
+			_main_outs->allow_pan_reset ();
+			_main_outs->reset_panner ();
+
+		} else {
+			
+			/* reconnect existing ports */
+
+			boost::shared_ptr<Port> oleft (_output->nth (0));
+			boost::shared_ptr<Port> oright (_output->nth (1));
+			if (oleft) {
+				oleft->connect (left);
+			}
+			if (oright) {
+				oright->connect (right);
+			}
 		}
-		
-		if (right.length()) {
-			_output->add_port (right, this, DataType::AUDIO);
-		}
-		
-		_main_outs->allow_pan_reset ();
-		_main_outs->reset_panner ();
+			
 	}
 
-	_output->changed.connect_same_thread (*this, boost::bind (&Auditioner::output_changed, this, _1, _2));
-
-        return 0;
-}
-
-Auditioner::~Auditioner ()
-{
+	return 0;
 }
 
 AudioPlaylist&

libs/ardour/route.cc

@@ -544,6 +544,7 @@ Route::monitor_run (framepos_t start_frame, framepos_t end_frame, pframes_t nfra
 {
 	assert (is_monitor());
 	BufferSet& bufs (_session.get_route_buffers (n_process_buffers()));
+	fill_buffers_with_input (bufs, _input, nframes);
 	passthru (bufs, start_frame, end_frame, nframes, declick);
 }
 

libs/ardour/session.cc

@@ -805,6 +805,12 @@ Session::remove_monitor_section ()
 	/* force reversion to Solo-In-Place */
 	Config->set_solo_control_is_listen_control (false);
 
+	/* if we are auditioning, cancel it ... this is a workaround
+	   to a problem (auditioning does not execute the process graph,
+	   which is needed to remove routes when using >1 core for processing)
+	*/
+	cancel_audition ();
+
 	{
 		/* Hold process lock while doing this so that we don't hear bits and
 		 * pieces of audio as we work on each route.
@@ -835,6 +841,10 @@ Session::remove_monitor_section ()
 
 	remove_route (_monitor_out);
 	auto_connect_master_bus ();
+
+	if (auditioner) {
+		auditioner->connect ();
+	}
 }
 
 void
@@ -979,6 +989,10 @@ Session::add_monitor_section ()
 			(*x)->enable_monitor_send ();
 		}
 	}
+
+	if (auditioner) {
+		auditioner->connect ();
+	}
 }
 
 void

libs/ardour/session_process.cc

@@ -875,7 +875,7 @@ Session::process_audition (pframes_t nframes)
 
 	/* if using a monitor section, run it because otherwise we don't hear anything */
 
-	if (auditioner->needs_monitor()) {
+	if (_monitor_out && auditioner->needs_monitor()) {
 		_monitor_out->monitor_run (_transport_frame, _transport_frame + nframes, nframes, false);
 	}