From 0ab95ff2dc2de2afe18c18c608e6c2bdd2bd02bf Mon Sep 17 00:00:00 2001
From: Assar Westerlund <assar@sics.se>
Date: Tue, 10 Mar 1998 08:56:13 +0000
Subject: [PATCH] (AC_KRB_IPV6): rewrote to avoid false positives

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@4564 ec53bebd-3082-4978-b11e-865c3cabbd6b
---
 acinclude.m4 | 49 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index fdf87f084..3dfd4b973 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -697,12 +697,47 @@ if test "$ac_cv_func_vsnprintf_working" = yes; then
 fi
 ])
 
+dnl
+dnl test for IPv6
+dnl
+
 AC_DEFUN(AC_KRB_IPV6, [
-AC_MSG_CHECKING(for IPv6)
-foo=no
-AC_EGREP_HEADER(sockaddr_in6, netinet/in.h,
-AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6) foo=yes)
-AC_EGREP_HEADER(sockaddr_in6, netinet/in6.h,
-AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6) foo=yes)
-AC_MSG_RESULT($foo)
+AC_CACHE_CHECK(for IPv6,ac_cv_lib_ipv6,
+AC_TRY_COMPILE([
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_NETINET_IN6_H
+#include <netinet/in6.h>
+#endif
+],
+[
+#if defined(IN6ADDR_ANY_INIT)
+struct in6_addr any = IN6ADDR_ANY_INIT;
+#elif defined(IPV6ADDR_ANY_INIT)
+struct in6_addr any = IPV6ADDR_ANY_INIT;
+#else
+#error no any?
+#endif
+ struct sockaddr_in6 sin6;
+ int s;
+
+ s = socket(AF_INET6, SOCK_DGRAM, 0);
+
+ sin6.sin6_family = AF_INET6;
+ sin6.sin6_port = htons(17);
+ sin6.sin6_addr = any;
+ bind(s, (struct sockaddr *)&sin6, sizeof(sin6));
+],
+ac_cv_lib_ipv6=yes,
+ac_cv_lib_ipv6=no))
+if test "$ac_cv_lib_ipv6" = yes; then
+  AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6)
+fi
 ])