[bug-inetutils] Implicit dependency in telnetd and telnet.

[Mats Andersson]

Dear all,

I happen to observe some non-elementary dependecies on
'struct termio' within telnetd/state.c,utility.c, and some
convoluted effects of HAVE_LIBREADLINE in "telnet/" and "telnetd/".

On NexentaCore without libreadline5-dev

   * telnet builds

   * telnetd must be mended:

      telnetd/state.h  must get NTELOPTS manually set

      telnetd/utility.c must see "<termio.h>" included.

On the other hand, once libreadline5-dev is installed,
then telnet as well as telnetd fails to compile. The
cause of this is the need to write

   /* telnet/telnet.c  and  telnetd/utility.c */

   #if HAVE_LIBREADLINE
   #  include <curses.h>
   #  include <term.h>
   #endif

Obviously GNU/Linux, GNU/kFreeBSD, and *BSD can make do
without explicit "<curses.h>", but OpenSolaris can not.

A related phenomenon is that GNU/Linux with libreadline
is able to include <termio.h> automatically, which happens
to be crucial in telnetd/utility.c, since HAVE_TERMIO_H
is generally unset, still the later use of "struct termio"
passes unnoticed.

Please evaluate what consequences the above insertion of
<curses.h> as well as the additions

   /* telnetd/state.c */

   #if !defined NTELOPT && defined TELOPT_NEW_ENVIRON
   #  define NTELOPTS  (1 + TELOPT_NEW_ENVIRON)
   #endif


   /* telnetd/utility.c

   #if defined HAVE_TERMIO_H || defined __sun__
   #  include <termio.h>
   #endif

would have on other systems. The indicated three changes are
the minimal actions needed to build on OpenSolaris with and
without the support of libreadline5.


Best regards,
  Mats