# File lib/active_record/vendor/mysql.rb, line 103
  def real_connect(host=nil, user=nil, passwd=nil, db=nil, port=nil, socket=nil, flag=nil)
    @server_status = SERVER_STATUS_AUTOCOMMIT
    if (host == nil or host == "localhost") and defined? UNIXSocket then
      unix_socket = socket || ENV["MYSQL_UNIX_PORT"] || MYSQL_UNIX_ADDR
      sock = UNIXSocket::new(unix_socket)
      @host_info = Error::err(Error::CR_LOCALHOST_CONNECTION)
      @unix_socket = unix_socket
    else      
      sock = TCPSocket::new(host, port||ENV["MYSQL_TCP_PORT"]||(Socket::getservbyname("mysql","tcp") rescue MYSQL_PORT))
      @host_info = sprintf Error::err(Error::CR_TCP_CONNECTION), host
    end
    @host = host ? host.dup : nil
    sock.setsockopt Socket::SOL_SOCKET, Socket::SO_KEEPALIVE, true
    @net = Net::new sock

    a = read
    @protocol_version = a.slice!(0)
    @server_version, a = a.split(/\0/,2)
    @thread_id, @scramble_buff = a.slice!(0,13).unpack("La8")
    if a.size >= 2 then
      @server_capabilities, = a.slice!(0,2).unpack("v")
    end
    if a.size >= 16 then
      @server_language, @server_status = a.slice!(0,3).unpack("cv")
    end

    flag = 0 if flag == nil
    flag |= @client_flag | CLIENT_CAPABILITIES
    flag |= CLIENT_CONNECT_WITH_DB if db

    @pre_411 = (0 == @server_capabilities & PROTO_AUTH41)
    if @pre_411
      data = Net::int2str(flag)+Net::int3str(@max_allowed_packet)+
             (user||"")+"\0"+
                   scramble(passwd, @scramble_buff, @protocol_version==9)
    else
      dummy, @salt2 = a.unpack("a13a12")
      @scramble_buff += @salt2
      flag |= PROTO_AUTH41
      data = Net::int4str(flag) + Net::int4str(@max_allowed_packet) +
             ([8] + Array.new(23, 0)).pack("c24") + (user||"")+"\0"+
             scramble41(passwd, @scramble_buff)
    end

    if db and @server_capabilities & CLIENT_CONNECT_WITH_DB != 0
      data << "\0" if @pre_411
      data << db
      @db = db.dup
    end
    write data
    pkt = read
    handle_auth_fallback(pkt, passwd)
    ObjectSpace.define_finalizer(self, Mysql.finalizer(@net))
    self
  end