launcher: do not touch VT/tty while using non-default seat

Launcher-direct does not allow us to run using a different
seat from the default seat0. This happens because VTs are
only exposed to the default seat, and users that are on
non-default seat should not touch VTs.

Add check in launcher-direct to skip VT/tty management if user
is running on a non-default seat.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>

libweston/launcher-direct.c

@@ -301,10 +301,14 @@ launcher_direct_connect(struct weston_launcher **out, struct weston_compositor *
 	launcher->base.iface = &launcher_direct_iface;
 	launcher->compositor = compositor;
 
+	if (strcmp("seat0", seat_id) == 0) {
 		if (setup_tty(launcher, tty) == -1) {
 			free(launcher);
 			return -1;
 		}
+	} else {
+		launcher->tty = -1;
+	}
 
 	* (struct launcher_direct **) out = launcher;
 	return 0;
@@ -315,11 +319,11 @@ launcher_direct_destroy(struct weston_launcher *launcher_base)
 {
 	struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
 
+	if (launcher->tty >= 0) {
 		launcher_direct_restore(&launcher->base);
 		wl_event_source_remove(launcher->vt_source);
-
-	if (launcher->tty >= 0)
 		close(launcher->tty);
+	}
 
 	free(launcher);
 }