The xdg-decoration protocol doesn't specify how unmapped toplevels must be handled
If the xdg_toplevel surface is unmapped, the compositor will reset its state. This includes resetting the caption, the window geometry, the minimum and the maximum size, etc.
Currently, the xdg-decoration protocol spec doesn't specify what must happen to the xdg_toplevel_decoration object if the xdg_toplevel surface is unmapped. Possible actions:
- Make the xdg_toplevel_decoration object inert
- Destroy the xdg_toplevel_decoration object
- Expect that the client will destroy the xdg_toplevel_decoration object before attaching a null wl_buffer
- Reset the xdg_toplevel_decoration object
- Simply do nothing?