Triggering "Show Desktop" and un-triggering it does not preserve window order

[RalfJung]

I have Super+D set up to be the hotkey for showing the desktop. I would expect that hitting Super+D twice will restore the window order that I started with. That is however not always the case.

I can reproduce this by having the Cinnamon system settings as the topmost window: If I now do Super+D twice, system settings moved "one layer down" the stack, it's the second-topmost window now. It should, instead, remain the topmost window.

[mtwebster]

Already fixed in muffin master: linuxmint/muffin@8bdd425