[PATCH wayland] RFC: Require WAYLAND_DISPLAY to be set instead of using wayland-0 as the default

[Peter Hutterer]

On Wed, Aug 12, 2015 at 02:41:08PM +0300, Pekka Paalanen wrote:
> On Mon, 25 May 2015 01:12:15 -0700
> Dima Ryazanov <dima at gmail.com> wrote:
> 
> > Although defaulting to wayland-0 seems convenient, it has an undesirable
> > side effect: clients may unintentionally connect to the wrong compositor.
> > Generally, it's safer to fail instead. Here's a real example:
> > 
> > In Fedora 22, Gtk+ prefers Wayland over X11, though the default session is still
> > a normal X11 Gnome session. When you launch a Gtk+ app, it will try Wayland,
> > fail, then try X11, and succesfully start up. That works fine.
> > 
> > Now suppose you launch Weston while running the Gnome session. Suddenly, all
> > of the Gtk+ apps launched from Gnome will show up inside Weston instead.
> > That's unexpected. There's also no good way to prevent that from happening
> > (other than perhaps setting WAYLAND_DISPLAY to an invalid value when launching
> > an app).
> > 
> > Not using wayland-0 as the default will solve that problem: an app launched
> > from the X11 Gnome session will use the X11 backend regardless of whether
> > there's a wayland compositor running at the same time.
> > 
> > Everything else should work as before. The compositor already sets
> > the WAYLAND_DISPLAY when starting the session, so the lack of the default value
> > should not make a difference to the user.
> > 
> > Signed-off-by: Dima Ryazanov <dima at gmail.com>
> 
> Hi,
> 
> gathering the comments from the thread, it seems we have Acked-bys from:
> Pekka Paalanen <ppaalanen at gmail.com>
> Giulio Camuffo <giuliocamuffo at gmail.com>
> Daniel Stone <daniel at fooishbar.org>
> "Jasper St. Pierre" <jstpierre at mecheye.net>
> 
> Seems like a pretty strong set. Would you like to send a non-RFC
> version of this patch?
> 
> I think you can include also the above Acked-bys.

if you need another vote to tilt the favours, you can add 
Acked-by: Peter Hutterer <peter.hutterer at who-t.net>

sorry, didn't see this earlier.

Cheers,
   Peter