We cannot handle just one of the two being NULL later down the road
(e.g. divide by zero in matrix projection code),
just ignore any such configure request.
Found through static analysis
This changes the `wlr_output_impl.set_cursor` function to take a
`wlr_texture` instead of a byte buffer. This simplifies the
DRM and Wayland backends since they were creating textures from
the byte buffer anyway.
With this commit, performance should be improved when moving the
cursor since outputs don't need to be re-rendered anymore.
- Textures are now immutable (apart from those created from raw
pixels), no more invalid textures
- Move all wl_drm stuff in wlr_renderer
- Most of wlr_texture fields are now private
- Remove some duplicated DMA-BUF code in the DRM backend
- Add more assertions
- Stride is now always given as bytes rather than pixels
- Drop wl_shm functions
Fun fact: this patch has been written 10,000 meters up in the air.
The backend destroy signal is emitted before the output_remove
signal is. When the destroy signal is emitted listeners remove
their output_remove listener, so the output_remove signal is never
received and listeners have an invalid output pointer.
The correct way to solve this would be to remove the output_remove
signal completely and use the wlr_output.events.destroy signal
instead. This isn't yet possible because wl_signal_emit is unsafe
and listeners cannot be removed in listeners.