Created attachment 122602 [details]
Weston renders sub-surfaces with a not mapped parent. According to the Wayland spec a sub-surface should only be mapped if the parent is mapped: "A sub-surface becomes mapped, when a non-NULL wl_buffer is applied and the parent surface is mapped."
* run systemsettings5
* go to Desktop Behavior -> Desktop Effects
* this creates a sub-surface tree with not mapped parents, but the child is visible
Please see the attached log with WAYLAND_DEBUG of systemsettings. The last child which is incorrectly rendered is wl_surface@97 which is a sub-surface to wl_surface@65, but wl_surface@65 never gets a buffer attached.
This is of course also a client bug which is reported at https://bugreports.qt.io/browse/QTBUG-52192, but of course the compositor should behave according to the spec ;-)
Series sent upstream:
-- GitLab Migration Automatic Message --
This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.
You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/wayland/weston/issues/74.