ssh not using priv port if target prot not priv

[Michael Stein]

The openSSH ssh command appears to not use a source privileged port
(no matter what the options/configs) if the target port
isn't a privileged port.

For example:

ssh -p 22222 foo.ucla.edu

would never try to connect from a privileged port.  Even with
useprivilegedport=yes.  This disallows .shosts RSA host authentication
without a password.

This breaks compatability with ssh-1.2.27 and isn't documented anywhere
except possibly in the source to the ssh_create_socket function in
sshconnect.c:

        /*
         * If we are running as root and want to connect to a privileged
         * port, bind our own socket to a privileged port.
         */
        if (privileged) {
                int p = IPPORT_RESERVED - 1;
                sock = rresvport_af(&p, family);
                if (sock < 0)
                        error("rresvport: af=%d %.100s", family, strerror(errno)
);
                else
                        debug("Allocated local port %d.", p);
        } else {
                /*
                 * Just create an ordinary socket on arbitrary port.  We use
                 * the user's uid to create the socket.
                 */
                temporarily_use_uid(original_real_uid);
                sock = socket(family, SOCK_STREAM, 0);
                if (sock < 0)
                        error("socket: %.100s", strerror(errno));
                restore_uid();
        }

It would make more sense to me that "useprivilegedport=yes" would result
in the use of a privileged port (assuming possible) no matter what the
target port was.

Is there any real reason that the ssh target port should affect the
choice of source port?