The BufferInterface used nested calls of wl_shm_buffer_begin_access
and allowed multiple different BufferInterfaces to be in a block
between wl_shm_buffer_begin_access and wl_shm_buffer_end_access.
But this is not allowed: nesting is only possible if it accesses
the same buffer!
This resulted in an abort when we accessed two BufferInterfaces
at the same time. The added test case aborts in the previous
version.
The fix now changes the semantic of the method. The BufferInterface
doesn't hold the QImage any more, but creates a new one every time
::data is invoked. The QImage is created with a custom cleanup
function which calls to wl_shm_buffer_end_access. It ensures that
we don't call into wl_shm_buffer_begin_access as long as there is
a valid QImage for any other BufferInterface still around and
instead returns a null QImage.
Thus a user of a BufferInterface::data should destroy the returned
QImage as soon as it's no longer needed or create a deep copy if
it needs to be kept around.
This makes it possible to install and then use it. Installation is still
commented since we can't give enough stability guarantees for now.
In detail:
- do not actually install headers
- generate the export header into Wayland/Server
- include it from there
REVIEW:120579
It also adds a
static SurfaceInterface *get(wl_resource*)
to SurfaceInterface which can find the SurfaceInterface for the
given wl_resource. This is needed for ShellSurfaceInterface which
can no longer just cast the wayland user data.
