restore being able to load a 5.12 session with a destructive track.

Not all is working right yet, however

libs/ardour/ardour/source.h

@@ -53,7 +53,8 @@ public:
 		RemovableIfEmpty = 0x10,
 		RemoveAtDestroy = 0x20,
 		NoPeakFile = 0x40,
-		/* 0x80 was Destructive */
+		/* No longer in use but kept to allow loading of older sessions */
+		Destructive = 0x80,
 		Empty = 0x100, /* used for MIDI only */
 		RF64_RIFF = 0x200,
 		Missing = 0x400, /* used for MIDI only */

libs/ardour/ardour/types.h

@@ -227,6 +227,8 @@ enum MeterType {
 enum TrackMode {
 	Normal,
 	NonLayered,
+	/* No longer in use but kept to allow loading of older sessions */
+	Destructive,
 };
 
 enum NoteMode {

libs/ardour/audio_track.cc

@@ -143,6 +143,11 @@ AudioTrack::set_state (const XMLNode& node, int version)
 		_mode = Normal;
 	}
 
+	if (_mode == Destructive) {
+		/* XXX warn user */
+		_mode = Normal;
+	}
+
 	if (Track::set_state (node, version)) {
 		return -1;
 	}

libs/ardour/enums.cc

@@ -248,6 +248,10 @@ setup_enum_writer ()
 
 	REGISTER_ENUM (Normal);
 	REGISTER_ENUM (NonLayered);
+	/* No longer used but we leave this here so that enumwriter can parse
+	 * strings containing "Destructive"
+	 */
+	REGISTER_ENUM (Destructive);
 	REGISTER (_TrackMode);
 
 	REGISTER_ENUM (Sustained);
@@ -519,6 +523,10 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (Source, RemovableIfEmpty);
 	REGISTER_CLASS_ENUM (Source, RemoveAtDestroy);
 	REGISTER_CLASS_ENUM (Source, NoPeakFile);
+	/* No longer used but we leave this here so that enumwriter can parse
+	 * strings containing "Destructive"
+	 */
+	REGISTER_CLASS_ENUM (Source, Destructive);
 	REGISTER_CLASS_ENUM (Source, Empty);
 	REGISTER_BITS (_Source_Flag);
 

libs/ardour/source.cc

@@ -167,6 +167,10 @@ Source::set_state (const XMLNode& node, int version)
 		_flags = Flag (0);
 	}
 
+	/* Destructive is no longer valid */
+
+	_flags = Flag (_flags & ~Destructive);
+
 	if (!node.get_property (X_("take-id"), _take_id)) {
 		_take_id = "";
 	}