In OpenSSH 3.6.1p2, Red Hat linux 8.0:

When I ssh to a host with a proxy command, I get the following message:

$ ssh tooth.toronto.redhat.com
getsockopt TCP_NODELAY: Socket operation on non-socket

Then things work normally.

The problem seems to be that a "return;" has been deleted from the function
"packet_set_interactive" in packet.c.  The code reads:

	/* Only set socket options if using a socket.  */
	if (!packet_connection_is_on_socket())
	if (interactive)
		set_nodelay(connection_in);

The odd indentation suggests that something has gone wrong.  The logic doens't
make any sense, either: if the connection is not on a socket, then one shouldn't
try to set socket options on it.  Finally, in 3.4p1, the code reads:

	/* Only set socket options if using a socket.  */
	if (!packet_connection_is_on_socket())
		return;

So it looks to me as if the 'return;' after the call to
packet_connection_is_on_socket got accidentally deleted.