Enable some key release event forwarding

This is needed for the virtual MIDI keyboard to trigger note-off events

gtk2_ardour/ardour_window.cc

@@ -71,6 +71,20 @@ ArdourWindow::on_key_press_event (GdkEventKey* ev)
 	return handled;
 }
 
+bool
+ArdourWindow::on_key_release_event (GdkEventKey* ev)
+{
+	bool handled = Gtk::Window::on_key_press_event (ev);
+
+	if (!handled) {
+		if (!get_modal()) {
+			handled = relay_key_press (ev, this);
+		}
+	}
+
+	return handled;
+}
+
 bool
 ArdourWindow::on_focus_in_event (GdkEventFocus *ev)
 {

gtk2_ardour/ardour_window.h

@@ -47,6 +47,7 @@ protected:
 	bool on_focus_out_event (GdkEventFocus*);
 	bool on_delete_event (GdkEventAny *);
 	bool on_key_press_event (GdkEventKey*);
+	bool on_key_release_event (GdkEventKey*);
 	void on_unmap ();
 
 private:

gtk2_ardour/meterbridge.cc

@@ -275,8 +275,7 @@ Meterbridge::on_key_release_event (GdkEventKey* ev)
 	if (gtk_window_propagate_key_event (GTK_WINDOW(gobj()), ev)) {
 		return true;
 	}
-	/* don't forward releases */
-	return true;
+	return relay_key_press (ev, this);
 }
 
 bool

gtk2_ardour/plugin_ui.cc

@@ -439,13 +439,13 @@ PluginUIWindow::on_key_release_event (GdkEventKey *event)
 		if (_pluginui) {
 			if (_pluginui->non_gtk_gui()) {
 				_pluginui->forward_key_event (event);
+				return true;
 			}
 		}
 	} else {
 		gtk_window_propagate_key_event (GTK_WINDOW(gobj()), event);
 	}
-	/* don't forward releases */
-	return true;
+	return relay_key_press (event, this);
 }
 
 void