The function xwl_window_swap_pixmap() can be called from two places,
either from xwl_window_attach_buffer() or from damage_report().
When called from xwl_window_attach_buffer(), the new buffer is attached
and the surface committed.
However, when called from damage_report(), a new buffer might not be
attached before the surface is committed.
That's fine with implicit synchronization, but if we use explicit
synchronization, committing a surface without a new buffer attached but
with a release timeline point set is a protocol error:
| If at surface commit time there is a pending release timeline point
| set but no pending buffer attached, a no_buffer error is raised.
To avoid such an issue, add a new parameter to xwl_window_swap_pixmap()
to hint whether it should set the synchronization points, and have the
synchronization points set only from xwl_window_attach_buffer().
v2: Rename param to handle_sync (Michel)
Suggested-by: Michel Dänzer <mdaenzer@redhat.com>
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1571>
aab01c7391