xwayland: non-rootless requires the wl_shell protocol

When running non-rootless, Xwayland requires that the Wayland compositor
supports the wl_shell protocol.

Check for wl_shell protocol support at startup and exit cleanly if
missing rather than segfaulting later in ensure_surface_for_window()
while trying to use wl_shell_get_shell_surface().

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
(cherry picked from commit ffd02d9b26bd560849c407a6dd4f5c4d7d2c1736)

1 files changed, 5 insertions, 0 deletions

diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c
index a69188c0f..21434c6e5 100644
--- a/hw/xwayland/xwayland.c
+++ b/hw/xwayland/xwayland.c
@@ -1202,6 +1202,11 @@ xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
                              &registry_listener, xwl_screen);
     xwl_screen_roundtrip(xwl_screen);
 
+    if (!xwl_screen->rootless && !xwl_screen->shell) {
+        ErrorF("missing wl_shell protocol\n");
+        return FALSE;
+    }
+
     bpc = xwl_screen->depth / 3;
     green_bpc = xwl_screen->depth - 2 * bpc;
     blue_mask = (1 << bpc) - 1;