[Python-apps-team] Bug#681051: xpra: menus pop up off-screen

[Michal Suchanek]

Excerpts from Antoine Martin's message of Tue Jul 10 17:11:02 +0200 2012:
> On 10/07/12 21:18, Michal Suchanek wrote:
> > Excerpts from Antoine Martin's message of Tue Jul 10 13:46:34 +0200 2012:
> >> On 10/07/12 18:37, Michal Suchanek wrote:
> >>> Excerpts from Antoine Martin's message of Tue Jul 10 11:29:03 +0200 2012:
> >>>> Please see here:
> >>>> https://www.xpra.org/Xdummy.html
> >>>>
> >>>> This is the only workable fix for this problem.
> >>>
> >>> These are packaged in Debian.
> >>>
> >>> Why is the bug happening still?
> >> Because you are using the default Xvfb and not Xdummy.
> >>
> >> See the bottom of the page on how to setup xpra to use Xdummy using the
> >> "--xvfb=" switch.
> >
> > Then the part of the man page saying
> >
> >     xpra start
> >            This command starts a new xpra server, including any necessary
> >       setup.
> >
> > is misleading at best if not outright wrong.
> I don't understand what you are saying. It does what it says, it is just 
> that for an optimal setup you should use Xdummy instead of Xvfb.
> The man page is not the place to start writing a novel about the best 
> way to setup your x11 server (Xdummy vs Xvfb, dbus, various agents and 
> whatnot)

Indeed, it is not.

However, the SEE ALSO section is meant to provide pointers to more
exhaustive documentation.

Only the BUGS section mentions Xdummy but no information on how it is
used.

I guess README.Debian would be suitable place for articles at least.
A novel would be somewhat excessive in this case.

> 
> This is mostly a dependency and packaging issue though: at present xpra 
> depends on Xvfb. Making Xdummy the default is a long term goal, but 
> until most distributions start packaging recent versions of Xorg (1.12 
> or later) and of the dummy driver (0.3.5), Xvfb will remain the default.

Debian is one of such distribution but still defaults to Xvfb.

> 
> Feel free to provide this better wording you speak of.

Looking at Debian Xsession man page, the wiki, and the Xvfb defaults
from the xpra man page you could possibly start a somewhat workable X
session with

xpra --xvfb="Xorg -nolisten tcp -noreset +extension GLX +extension RANDR +extension RENDER -logfile ./10.log -config ./xorg.conf"  --start-child="/etc/X11/Xsession true" start :10

Note the -noreset option which is omitted on the wiki and without which
the session setup will not work.

Note also that the true command exits immediately so any dbus,
ssh-agent, and similar daemons started by the session will exit
immediately as well.

You could run a non-ending process instead but then the session daemons
would stay even after the X server exits.

A client that connects to the X server and waits for it to terminate
would be ideal but I know of none that does just this.

Perhaps some sample script in documentation, or perhaps even a
xorg.conf.dummy and a script in /usr/bin using it could be installed
with xpra so that everyone does not have to figure out how the hell is
that thing supposed to work.

A sample script using xorg.conf.dummy could look like this:

xpra --xvfb="Xorg -nolisten tcp -config xorg.conf.dummy -noreset +extension GLX +extension RANDR +extension RENDER -logfile ~/.xpra/xserver-$DISPLAY.log" --start-child="/etc/X11/Xsession true" start :$DISPLAY

It is sad that you can't know what display xpra picks when starting it
but without actually patching xpra you can't do more than that.

Thanks

Michal