2015-05-26 12:21 GMT+03:00 Pekka Paalanen <[email protected]>: > On Mon, 25 May 2015 01:12:15 -0700 > Dima Ryazanov <[email protected]> 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. > > Hi, > > I have a vague recollection this has been proposed before, but I can't > remember if there was any interest or discussion, nor what was the > original intent behind defaulting to "wayland-0". > > Personally I'd be fine with this change, but I can't imagine what would > break if we did this.
I think it is quite safe. All compositors need to export WAYLAND_DISPLAY anyway in case they use a different socket that wayland-0. What we could break is users starting apps, say, from a tty, but i think that's acceptable if we put a big warning in the release notes. It's not like they need to patch software to fix it. -- Giulio > > Need more opinions. > > > Thanks, > pq > _______________________________________________ > wayland-devel mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/wayland-devel _______________________________________________ wayland-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/wayland-devel
