Don't return 0 from ssl2_read when a packet with empty payload is received.

 Changes between 0.9.2b and 0.9.3

  *) Change behaviour of ssl2_read when facing length-0 packets: Don't return

     0 (which usually indicates a closed connection), but continue reading.

     [Bodo Moeller]

  *) Fix some race conditions.

     [Bodo Moeller]

	int i;

	unsigned int mac_size=0;

ssl2_read_again:

	if (SSL_in_init(s) && !s->in_handshake)

		{

		n=s->handshake_func(s);

		INC32(s->s2->read_sequence); /* expect next number */

		/* s->s2->ract_data is now available for processing */

#if 1

		/* How should we react when a packet containing 0

		 * bytes is received?  (Note that SSLeay/OpenSSL itself

		 * never sends such packets; see ssl2_write.)

		 * Returning 0 would be interpreted by the caller as

		 * indicating EOF, so it's not a good idea.

		 * Instead, we just continue reading.  Note that using

		 * select() for blocking sockets *never* guarantees

		 * that the next SSL_read will not block -- the available

		 * data may contain incomplete packets, and except for SSL 2

		 * renegotiation can confuse things even more. */

		goto ssl2_read_again; /* This should really be

				       * "return ssl2_read(s,buf,len)",

				       * but that would allow for

				       * denial-of-service attacks if a

				       * C compiler is used that does not

				       * recognize end-recursion. */

#else

		/* If a 0 byte packet was sent, return 0, otherwise

		 * we play havoc with people using select with

		 * blocking sockets.  Let them handle a packet at a time,

		if (s->s2->ract_data_length == 0)

			return(0);

		return(ssl2_read(s,buf,len));

#endif

		}

	else

		{