Nested popup windows crash mutter on close
We have a use case, which involves creation of nested popup windows (one main popup and a second popup near that main popup) without using explicit grab.
That is, we destroy xdg_v6_popup and xdg_v6_surface, attach null buffer to our wl_surface and keep that wl_surface when Hide() call comes. But that popup, which is located on top of the stack, is not hidden. What is more, mutter crashes, when another buffer is attached to the main popup (I will share the backtrace tomorrow).