Applied Joe Halpin's bugfixes to the NI_WITHSCOPEID test program.

  AC_CACHE_CHECK(for working NI_WITHSCOPEID, ac_cv_working_ni_withscopeid,[

 AC_RUN_IFELSE([[

#include <stdio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netdb.h>

int main()

{

#ifdef NI_WITHSCOPEID

   struct sockaddr_storage ss;

   int sslen;

   int sslen = sizeof(ss);

   int rc;

   char hbuf[NI_MAXHOST];

   int fd = socket(AF_INET6, SOCK_STREAM, 0);

   if(fd < 0) {

     printf("couldn't create AF_INET6 socket\n");

     return 4; /* couldn't create socket of either kind */

     perror("socket()");

     return 1; /* couldn't create socket of either kind */

   }

   rc = getsockname(fd, (struct sockaddr *)&ss, &sslen);

   if(rc) {

     printf("getsockname() failed\n");

     return 1; /* getsockname() failed unexpectedly */

     perror("getsockname()");

     return 2;

   }

   rc = getnameinfo((struct sockaddr *)&ss, sslen, hbuf, sizeof(hbuf),

   if(rc) {

     printf("rc = %s\n", gai_strerror(rc));

     return 2; /* getnameinfo() failed, we take this as an indication to

                  avoid NI_WITHSCOPEID */

     return 3;

   }

   return 0; /* everything works fine, use NI_WITHSCOPEID! */

#else

   return 3; /* we don't seem to have the definition, don't use it */

   return 4; /* we don't seem to have the definition, don't use it */

#endif

}

]],