L: only renumber tracks after track DnD if we passed the move threshold

gtk2_ardour/editor.cc

@@ -7240,6 +7240,13 @@ Editor::mid_track_drag (GdkEventMotion* ev, Gtk::Widget& w)
 	w.translate_coordinates (edit_controls_vbox, ev->x, ev->y, xo, yo);
 
 	if (track_drag->first_move) {
+
+		/* move threshold */
+
+		if (abs (yo - track_drag->previous) < (int) (4 * UIConfiguration::instance().get_ui_scale())) {
+			return;
+		}
+
 		if (!track_drag->track->selected()) {
 			set_selected_track (*track_drag->track, Selection::Set, false);
 		}
@@ -7275,14 +7282,17 @@ Editor::end_track_drag ()
 		gdk_window_set_cursor (edit_controls_vbox.get_toplevel()->get_window()->gobj(), track_drag->predrag_cursor);
 	}
 
-	delete track_drag;
-	track_drag = nullptr;
+	bool did_move = !track_drag->first_move;
+
+ 	delete track_drag;
+ 	track_drag = nullptr;
 
 	/* the suspender was deleted with track_drag, now catch up on any track
 	   numbering and side effects
 	*/
-
-	_session->update_track_numbers ();
+	if (did_move) {
+		_session->update_track_numbers ();
+	}
 }
 
 bool