Bug#838777: Policy 11.8.4 for x-window-manager needs update for freedesktop menus

[Josh Triplett <josh@joshtriplett.org>]

On Sat, Sep 24, 2016 at 12:57:04PM -0700, Russ Allbery wrote:
> Josh Triplett <josh@joshtriplett.org> writes:
> 
> > Based on some conversations on #debian-devel on the purpose of
> > x-window-manager (as launched by
> > /etc/X11/Xsession.d/50x11-common_determine-startup), it seems like a
> > window manager that just manages windows, and expects a separately
> > launched menu/taskbar program or desktop environment to provide the
> > ability for the user to launch programs or otherwise do anything useful,
> > shouldn't register an x-window-manager alternative at all.  Otherwise,
> > the user might end up staring at a desktop they can't interact with at
> > all.
> 
> Er, this seems to imply that twm shouldn't register as x-window-manager,
> which sounds wrong and isn't how Debian has ever worked.  Or am I
> misunderstanding what you mean by "just manages windows"?

twm has a menu to launch additional applications; left-click on the
desktop.  So, it should continue registering an x-window-manager
alternative.

I'm talking about window managers like metacity or mutter, which without
an associated desktop environment provide no way to launch applications
or even exit.

> I realize that nearly everyone uses a desktop environment these days, but
> it used to be very common to just launch a windows manager and then use
> ~/.xsession to launch some xterms, and I don't think we want to break that
> functionality unless something is actually broken now.  I'm sure someone
> is still doing this.  Last time I checked, startx relies on the
> x-window-manager alternative to figure out what to start, so removing that
> alternative would break such a setup.

That uses the Xsession mechanism (and specifically the
/etc/X11/Xsession.d/50x11-common_determine-startup script that I
mentioned above).  Keeping that from breaking was exactly my concern
here: launching an X session should never leave the user with no way to
launch applications or exit (other than switching to another VT).