wayland: prevent resizing of fixed-size window

Clients can set minimum and maximum to identical values to indicate a
fixed-size window. A compositor can ignore these requests and thus a client
has to ensure these limits.
To support clients that do not ensure these size limits by themselves and
to skip unnecessary function calls, we will prevent resizing requests by
the client if a fixed-size has been requested.

https://gitlab.gnome.org/GNOME/mutter/-/issues/1331

src/wayland/meta-wayland-xdg-shell.c

@@ -351,6 +351,9 @@ xdg_toplevel_resize (struct wl_client   *client,
   if (!window)
     return;
 
+  if (!window->has_resize_func)
+    return;
+
   if (!meta_wayland_seat_get_grab_info (seat, surface, serial, TRUE, &x, &y))
     return;