avoid creating negative values out of unsigned values using MAX, check to

avoid creating negative values out of unsigned values using MAX, check to

Fri Oct 18 13:41:30 2002  Manish Singh  <yosh@gimp.org>

        * glib/giochannel.c (g_io_channel_read_line_backend): avoid
        creating negative values out of unsigned values using MAX,
        check to see if the result would be positive before doing
        the calculation.