protocol: Clarify semantics of sub-surface placement requests

Clarify some semantics of wl_subsurface.place_below and
wl_subsurface.place_below that were not specified.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Jasper St. Pierre <jstpierre@mecheye.net>

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 61fde84..b986c86 100644 (file)
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -1946,8 +1946,9 @@
        parent surface. Using any other surface, including this sub-surface,
        will cause a protocol error.
 
-       The z-order is double-buffered state, and will be applied on the
-       next commit of the parent surface.
+       The z-order is double-buffered. Requests are handled in order and
+       applied immediately to a pending state, then committed to the active
+       state on the next commit of the parent surface.
        See wl_surface.commit and wl_subcompositor.get_subsurface.
 
        A new sub-surface is initially added as the top-most in the stack