Until recently, if an event attempting to deliver an fd to a zombie
object was demarshalled after the object was made into a zombie, we
leaked the fd and left it in the buffer.
If another event attempting to deliver an fd to a live object was in that
same buffer, the zombie's fd would be delivered instead.
This test recreates that situation.
While this is a ridiculously contrived way to force this race - delivering
an event from a destruction handler - I do have reports of this race
being hit in real world code.
Signed-off-by: Derek Foreman <email@example.com>
Acked-by: Daniel Stone <firstname.lastname@example.org>