Multiplexing bug on client exit

[Iain Morgan]

Hi,

With the 20100127 snapshot, there appears to be a bug in the
multiplexing support that causes the master to die under some
circumstances when a slave session exits.

The error messages that I am getting are:

cfe1.imorgan> exit
Connection to cfe1 closed.
$ channel_by_id: 2: bad id: channel free
client_input_channel_req: channel 2: unknown channel
channel_by_id: 2: bad id: channel free
Disconnecting: Received oclose for nonexistent channel 2.

This is triggered by using a multiplexed connection to a bastion host
and a ProxyCommand (similar to netcat) associated with the slave session
to reach the host behind the bastion.

However, a slave connection to the same bastion does not exhibit this
problem, which makes me suspect that it has to do with the use of a
ProxyCommand over the muxed session.

The same configuration worked fine with 5.3p1.

-- 
Iain Morgan