Re: io_close proposal

> No...the port isn't destroyed, just moved.  

To be precise, I'm talking about the user's send right, not the port per se.

> While it is in transit, it is still in existence.  It gets to the server,
> which now has the user's send right.

That's how rights in a message bodies work.  But I don't think that is
really true for the receiver port, at least not when the message is
dequeued by the receiver (even if the send right exists in the message
while it's queued in the kernel).  As I read the manual, the receiver of
the message does not get a send right corresponding to msgh_local_port.
That's just the name of the receive right on which the message arrived.