fixed transition glitches

mainwindow.cpp

@@ -767,6 +767,10 @@ void MainWindow::setup_menus() {
 
 	tools_menu->addAction("Preferences", this, SLOT(preferences()), QKeySequence("Ctrl+."));
 
+#ifdef QT_DEBUG
+	tools_menu->addAction("Clear Undo", this, SLOT(clear_undo_stack()), QKeySequence("Ctrl+."));
+#endif
+
 	// INITIALIZE HELP MENU
 
 	QMenu* help_menu = menuBar->addMenu("&Help");
@@ -815,6 +819,10 @@ void MainWindow::paintEvent(QPaintEvent *event) {
 #endif
 }
 
+void MainWindow::clear_undo_stack() {
+	undo_stack.clear();
+}
+
 void MainWindow::open_project() {
 	QString fn = QFileDialog::getOpenFileName(this, "Open Project...", "", OLIVE_FILE_FILTER);
 	if (!fn.isEmpty() && can_close_project()) {