dramatic change in logic and naming for operations related to adding a MIDI region on demand and cloning/unlinking

Existing code would cause data loss due to creation of two Source objects referring the same path, one with removable flags and one without. Careful code review suggested a variety of thinkos, function naming problems and other confusion that caused this. I have tried ot extensively comment what is going on with these operations, because it is one key area in which MIDI differs from audio: with audio, capture is the only way to add a new audio region, but for MIDI there are GUI input events that can add a new region.

1 files changed, 4 insertions, 24 deletions

diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index d4452490fb..655222413a 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -332,29 +332,9 @@ MidiSource::mark_streaming_write_completed ()
 	mark_midi_streaming_write_completed (Evoral::Sequence<Evoral::MusicalTime>::DeleteStuckNotes);
 }
 
-boost::shared_ptr<MidiSource>
-MidiSource::clone (const string& path, Evoral::MusicalTime begin, Evoral::MusicalTime end)
+int
+MidiSource::write_to (boost::shared_ptr<MidiSource> newsrc, Evoral::MusicalTime begin, Evoral::MusicalTime end)
 {
-	string newpath;
-
-	/* get a new name for the MIDI file we're going to write to
-	 */
-	
-	if (path.empty()) {
-		string newname = PBD::basename_nosuffix(_name.val());
-		newname = bump_name_once (newname, '-');
-		newname += ".mid";
-		newpath = _session.new_source_path_from_name (DataType::MIDI, newname);
-	} else {
-		/* caller must check for pre-existing file */
-		assert (!Glib::file_test (path, Glib::FILE_TEST_EXISTS));
-		newpath = path;
-	}
-
-	boost::shared_ptr<MidiSource> newsrc = boost::dynamic_pointer_cast<MidiSource>(
-		SourceFactory::createWritable(DataType::MIDI, _session,
-		                              newpath, false, _session.frame_rate()));
-
 	newsrc->set_timeline_position(_timeline_position);
 	newsrc->copy_interpolation_from (this);
 	newsrc->copy_automation_state_from (this);
@@ -367,7 +347,7 @@ MidiSource::clone (const string& path, Evoral::MusicalTime begin, Evoral::Musica
 		}
 	} else {
 		error << string_compose (_("programming error: %1"), X_("no model for MidiSource during ::clone()"));
-		return boost::shared_ptr<MidiSource>();
+		return -1;
 	}
 
 	newsrc->flush_midi();
@@ -384,7 +364,7 @@ MidiSource::clone (const string& path, Evoral::MusicalTime begin, Evoral::Musica
 
 	boost::dynamic_pointer_cast<FileSource> (newsrc)->prevent_deletion ();
 
-	return newsrc;
+	return 0;
 }
 
 void