Lorenzo Colitti

Not sure if you've started this already, but if not, I started an implementation [here](https://github.com/WayfireWM/wayfire/pull/2162). It's not finished, but it seems to at least cover basic locking and unlocking using...

I managed to reproduce this with something like: $ swaylock & sleep 1; python create_wayland_output.py & (sleep 0.05; python destroy_wayland_output.py WL-1) Frame #7 in the stack trace is: ``` 124...

I thought de3f82b0bcf13c6e4a0db88a3b0d7cb6cb77d020 and 048e8d7bc8e299998b28d12cd4f4f2697bb70091 would fix this, but with those commits it looks like the code crashes in `wf::wlr_surface_controller_t::update_subsurface_order_and_position` instead.

> Is this not able to be fixed by only modifying the preserve-output plugin? Seems like that might be a better place for this to live. Perhaps, but why require...

> I think the idea in general makes sense when destroying an output. It might make sense to add more flags to the function (instead of a bool). Maybe even...

I hacked this locally and it seems better, but I don't think it's completely correct: ``` /* We have changed the size/number of toplevels. On top of that, our list...