diff --git a/src/calibre/gui2/main_window.py b/src/calibre/gui2/main_window.py index 5a4a3f6c61..eccc0be6d4 100644 --- a/src/calibre/gui2/main_window.py +++ b/src/calibre/gui2/main_window.py @@ -164,6 +164,9 @@ class MainWindow(QMainWindow): return QMainWindow.event(self, ev) def clone_menu(menu): + # This is needed to workaround a bug in Qt 5.5+ and Unity. When the same + # QAction object is used in both a QMenuBar and a QMenu, sub-menus of the + # QMenu flicker when rendered under Unity. def clone_action(ac, parent): if ac.isSeparator(): ans = QAction(parent)