If an OS or DE does not support global menus (ie: win32, LXDE, etc..) then we could handle this ourselves by adding a menu bar to the window and just offset the window contents. Original menu forwarding ticket: #228
This means using a widget inside the window, which could also be used for honouring the window gravity attribute, and may also fix windows being grabbed with KDE (r773).
For the html5 client, this will require #1471
Related to ticket:228#comment:14 : GNOME Plans to Move App Menus Back Inside App Windows - so maybe this thing is not going to be used any more, and so we won't have to deal with it.
See also #2163
wontfix: support for appmenus has been removed (#2163)
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1035