4 files changed, 8 insertions, 10 deletions
diff --git a/libs/ardour/ardour/smf_source.h b/libs/ardour/ardour/smf_source.h
index 7793b6a91c..e02f8eddc0 100644
--- a/libs/ardour/ardour/smf_source.h
+++ b/libs/ardour/ardour/smf_source.h
@@ -77,7 +77,7 @@ private:
 				 sframes_t stamp_offset,
 				 sframes_t negative_stamp_offset,
 				 MidiStateTracker* tracker) const;
-	
+
 	nframes_t write_unlocked (MidiRingBuffer<nframes_t>& src,
 			sframes_t position,
 			nframes_t cnt);
diff --git a/libs/ardour/midi_model.cc b/libs/ardour/midi_model.cc
index 688e766668..47bc14852c 100644
--- a/libs/ardour/midi_model.cc
+++ b/libs/ardour/midi_model.cc
@@ -688,12 +688,14 @@ MidiModel::write_to(boost::shared_ptr<MidiSource> source)
 	set_percussive(false);
 
 	source->drop_model();
+	source->mark_streaming_midi_write_started(note_mode(), _midi_source->timeline_position());
 
 	for (Evoral::Sequence<TimeType>::const_iterator i = begin(); i != end(); ++i) {
 		source->append_event_unlocked_beats(*i);
 	}
 
 	set_percussive(old_percussive);
+	source->mark_streaming_write_completed();
 
 	set_edited(false);
 
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index 133b75893d..09df32a275 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -219,14 +219,8 @@ MidiSource::mark_streaming_midi_write_started (NoteMode mode, sframes_t start_fr
 void
 MidiSource::mark_streaming_write_started ()
 {
-	sframes_t start_frame = _session.transport_frame();
-
-	if (_model) {
-		_model->start_write();
-	}
-
-	_last_write_end = start_frame;
-	_writing = true;
+	NoteMode note_mode = _model ? _model->note_mode() : Sustained;
+	mark_streaming_midi_write_started(note_mode, _session.transport_frame());
 }
 
 void
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index 6e8a0ee052..c940bd3331 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -183,7 +183,7 @@ SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& destination, sframes_t sour
 		} else {
 			break;
 		}
-		
+
 		_read_data_count += ev_size;
 
 		if (ev_size > scratch_size) {
@@ -268,6 +268,7 @@ SMFSource::write_unlocked (MidiRingBuffer<nframes_t>& source, sframes_t position
 void
 SMFSource::append_event_unlocked_beats (const Evoral::Event<double>& ev)
 {
+	assert(_writing);
 	if (ev.size() == 0)  {
 		return;
 	}
@@ -301,6 +302,7 @@ SMFSource::append_event_unlocked_beats (const Evoral::Event<double>& ev)
 void
 SMFSource::append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, sframes_t position)
 {
+	assert(_writing);
 	if (ev.size() == 0)  {
 		return;
 	}