MidiRegion::clone() needs to ensure that the model is loaded before calling MidiSource::write_to()

1 files changed, 11 insertions, 3 deletions

diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index 9b01b03f16..bb02a79fdd 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -178,10 +178,18 @@ MidiRegion::clone (boost::shared_ptr<MidiSource> newsrc) const
 	Evoral::Beats const bend = bfc.from (_start + _length);
 
 	{
+		boost::shared_ptr<MidiSource> ms = midi_source(0);
+		Source::Lock lm (ms->mutex());
+
+		if (!ms->model()) {
+			ms->load_model (lm);
+		}
+
 		/* Lock our source since we'll be reading from it.  write_to() will
-		   take a lock on newsrc. */
-		Source::Lock lm (midi_source(0)->mutex());
-		if (midi_source(0)->write_to (lm, newsrc, bbegin, bend)) {
+		   take a lock on newsrc.
+		*/
+
+		if (ms->write_to (lm, newsrc, bbegin, bend)) {
 			return boost::shared_ptr<MidiRegion> ();
 		}
 	}