[PATCH] libweston: Support autodetection of the current XDG_SEAT

[nerdopolis]

On Wednesday, August 16, 2017 4:50:15 AM EDT Pekka Paalanen wrote:
> On Tue, 15 Aug 2017 18:03:10 -0400
> nerdopolis <bluescreen_avenger at verizon.net> wrote:
> 
> > On Tuesday, August 15, 2017 3:36:48 PM EDT Armin Krezović wrote:
> > > On 15.08.2017 04:02, nerdopolis wrote:
> > > 
> > > Hi,
> > >   
> > > > ---
> > > >   libweston/compositor-drm.c   | 5 +++++
> > > >   libweston/compositor-fbdev.c | 5 +++++
> > > >   2 files changed, 10 insertions(+)
> > > > 
> > > > diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
> > > > index 10adb463..44b2e448 100644
> > > > --- a/libweston/compositor-drm.c
> > > > +++ b/libweston/compositor-drm.c
> > > > @@ -3502,8 +3502,13 @@ drm_backend_create(struct weston_compositor *compositor,
> > > >   	struct udev_device *drm_device;
> > > >   	struct wl_event_loop *loop;
> > > >   	const char *seat_id = default_seat;
> > > > +	const char *session_seat;
> > > >   	int ret;
> > > >   
> > > > +	session_seat=getenv("XDG_SEAT");
> > > > +	if (session_seat)
> > > > +		seat_id=session_seat;
> > > > +  
> > > 
> > > seat_id can already be overriden, using --seat=whatever weston option, as seen here:
> > > 
> > > https://cgit.freedesktop.org/wayland/weston/tree/compositor/main.c#n1224
> > > https://cgit.freedesktop.org/wayland/weston/tree/libweston/compositor-drm.c#n3549
> > > 
> > > Not sure if there's same thing for fbdev backend, but even if there's not, it should
> > > be implemented the same way.
> > >   
> > > >   	weston_log("initializing drm backend\n");
> > > >   
> > > >   	b = zalloc(sizeof *b);
> > > > diff --git a/libweston/compositor-fbdev.c b/libweston/compositor-fbdev.c
> > > > index e80a5040..81e5ec3b 100644
> > > > --- a/libweston/compositor-fbdev.c
> > > > +++ b/libweston/compositor-fbdev.c
> > > > @@ -712,6 +712,11 @@ fbdev_backend_create(struct weston_compositor *compositor,
> > > >   {
> > > >   	struct fbdev_backend *backend;
> > > >   	const char *seat_id = default_seat;
> > > > +	const char *session_seat;
> > > > +
> > > > +	session_seat=getenv("XDG_SEAT");
> > > > +	if (session_seat)
> > > > +		seat_id=session_seat;
> > > >   
> > > >   	weston_log("initializing fbdev backend\n");
> > > >   
> > > >   
> > > 
> > >   
> > 
> > Hi
> > pam_systemd.so sets the XDG_SEAT variable though
> > So if you're starting Weston where the session_seat is seat1, weston
> > won't start, unless you specify --seat=$XDG_SEAT
> > 
> > Which is OK, but then login managers would need to be aware of that
> > when starting Weston
> 
> Hi,
> 
> yeah, I think using XDG_SEAT by default if set would be nice, but the
> command line option must override that. I didn't read the patch
> carefully enough to see if it does. Probably could add a sentence in
> the man page and the weston --help output too.
> 
> 
> Thanks,
> pq
Hi. 

I will change the man and help output... ...as of now with this patch, the
--seat option does win over the XDG_SEAT variable

Thanks