building R-1.3.0

nanoftp.c:771: `AF_INET' undeclared (first use in this function)
nanoftp.c:781: `SOCK_STREAM' undeclared (first use in this function)
nanoftp.c:1090: `IPPROTO_TCP' undeclared (first use in this function)

I've learned a bit more about this, and I'd say I've probably
encountered a puzzle and a bug.

The puzzle:

  If I'm reading config.cache correctly, configure fails to locate
      /usr/include/netinet/tcp.h
  though it finds other files in the same directory

  from config.cache:
    ac_cv_header_netinet_in_h=${ac_cv_header_netinet_in_h=yes}
    ac_cv_header_netinet_tcp_h=${ac_cv_header_netinet_tcp_h=no}
  but
   -r--r--r--  1 root   root  23975 Jul 24  2000 /usr/include/netinet/in.h
   -r--r--r--  1 root   root   3754 Jul 24  2000 /usr/include/netinet/tcp.h

As a consequence of that decision, HAVE_BSD_NETWORKING is not defined.

The bug:

  nanoftp.c checks that macro before including tcp.h (and other
  files), but doesn't seem to do the right test later on when it uses
  the contents of the include files in question.

  All the code in the file is embedded in this test:
    #if !defined(Unix) || defined(HAVE_BSD_NETWORKING)

  While the test for including tcp.h (et al) is more stringent:
    #ifdef HAVE_BSD_NETWORKING