Val Packett authored Dec 07, 2018 and Daniel Stone committed Feb 16, 2019

Changing the focused surface did remove the surface_destroy_listener from the wl_signal list,
but destroying the focus state did not. As a result, sometimes the same listener would be added
to two surfaces, which would join their wl_signal lists together, which would cause infinite
loops and use-after-frees when closing desktop surfaces.