[PATCH wayland] protocol: Change wording of subsurface placement scheduling

[Jonas Ådahl]

Change wording to be more consistent with other parts of the subsurface
protocol. Before this change, wl_subsurface.set_position explicitly
stated that the new state was to be applied on the parents
wl_surface.commit and wl_subsurface.place_above/below only said "on
the next commit of the parent surface". What "committed" means is
ambiguous considering that a wl_surface.commit actually defers the
actual commit when in synchronized mode, but the intention has always
been that placement of a subsurface should be considered part of its
content, i.e. placement state should be applied when other state
(buffer, regions). This patch makes that more clear.

Note that prior to this patch, one could correctly have interpreted
the protocol meaning that placements operations takes effect explicitly
on wl_surface.commit of the parent surface no matter whether other state
of the parent surface is applied at that point. This patch clarifies that
that is not the case.

https://bugs.freedesktop.org/show_bug.cgi?id=88857

Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---
 protocol/wayland.xml | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 4fb8035..38e463a 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -2061,8 +2061,10 @@
 	coordinate system. The coordinates are not restricted to the parent
 	surface area. Negative values are allowed.
 
-	The next wl_surface.commit on the parent surface will reset
-	the sub-surface's position to the scheduled coordinates.
+	The scheduled coordinates will take effect whenever the state of the
+	parent surface is applied. When this happens depends on whether the
+	parent surface is in synchronized or not. See wl_subsurface.set_sync
+	and wl_subsurface.set_desync for details.
 
 	If more than one set_position request is invoked by the client before
 	the commit of the parent surface, the position of a new request always
@@ -2084,9 +2086,11 @@
 	will cause a protocol error.
 
 	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.
+	applied immediately to a pending state, then applied to the active
+	state the next time the state of the parent surface is applied. When
+	this happens depends on whether the parent surface is in synchronized
+	or not. See wl_subsurface.set_sync and wl_subsurfac.set_desync for
+	details.
 
 	A new sub-surface is initially added as the top-most in the stack
 	of its siblings and parent.
-- 
2.1.0