- 
    Bug 
- 
    Resolution: Fixed
- 
    P0: Blocker 
- 
    6.9
- 
    None
- 
        
- 
        e389b1e38 (dev), fb83ac619 (tqtc/lts-6.5), 34baf4540 (tqtc/lts-6.8)
When reshowing a hidden subwindow, Qt Wayland Compositor will issue a protocol error and crash the client. This does not happen with e.g. mutter
Create a simple Qt Widgets template app, add a QDialog *w member, then add a button to it and connect it to the following slot:
void MainWindow::toggleSubWindow()
{
    if (w == nullptr)
        w = new QDialog(this);
    if (w->isVisible())
        w->hide();
    else
        w->show();
}
Clicking the button three times crashes the app. This is likely triggered by https://codereview.qt-project.org/c/qt/qtwayland/+/583059