Qt::WindowTransparentForInput may crash app

qtbase\src\plugins\platforms\windows\qwindowscontext.cpp line 1075, there are somthing wrong if window->parent() is null
// code placeholder
    case QtWindows::LeaveEvent:
        {
            QWindow *window = platformWindow->window();
            while (window->flags() & Qt::WindowTransparentForInput)
                window = window->parent();
            if (!window)
                return false;