Sub menus do not open in Firefox about xpra

[totaam]

Xpra Server Version v5.0-r0

Are you sure about that?
If so, that's quite old and missing lots of geometry fixes.

Works for me with an X11 client and a Fedora server - I will check again as this could well be to a Wayland misfeature.

[totaam]

Yeah, looks like it's a Wayland feature again.
I can crash Weston every single time by clicking the menu, then clicking the xterm I started xpra from!
100% reliable crash after showing this message:

(Xpra:671626): Gdk-WARNING **: 12:53:49.437: Tried to map a popup with a non-top most parent

But eh, Wayland is better, safer, it's the future! Or something.

[totaam]

The warning comes from here and "explains" why the window is not shown:
https://gitlab.gnome.org/GNOME/gtk/-/blob/gtk-3-24/gdk/wayland/gdkwindow-wayland.c?ref_type=heads#L3019-L3026
Looks like providing the window parent (and ensuring it is mapped) would allow the popup to be shown?

[totaam]

And here's the popup window metadata that triggers the warning:

process_new_common: (67, 697, 477, 207, 97, { \
    'xid': 12583148, 'has-alpha': True, 'client-machine': 'fedora', 'pid': 665851,
    'title': 'Firefox', 'role': 'Popup', 'command': '/usr/lib64/firefox/firefox',
    'class-instance': ('Firefox', 'firefox'), 'opaque-region': (), 'transient-for-xid': 12582955, \
    'transient-for': 2, 'bypass-compositor': 2, 'group-leader-xid': 12582913, \
    'window-type': ('POPUP_MENU',), 'content-type': '', 'override-redirect': True \
}) (..) OR=True

The problem is that its parent is not the other popup.
This works fine on X11, but GTK refuses to show the popup on Wayland.

The commit above implements an ugly workaround, second guessing what WM_TRANSIENT_FOR really should point to.

Works-for-me... Although I did notice some pointer offsets under Wayland with Firefox, but that's a different issue.

[totaam]

Works-for-me.