Issue trusteddomainproject#203: configure.ac: Properly include header…

…s needed by resolve.h

before use it

configure.ac

@@ -116,8 +116,24 @@ AC_SEARCH_LIBS(getaddrinfo, resolv,
 # it, it conflicts with AC_LANG_CALL's redeclaration. Hmm. I guess the
 # only thing for it is to include resolv.h, don't redeclare res_ninit(),
 # and use the proper type signature when calling it.
+
+# Before using resolv.h, we need to check headers required for it.
+AC_HEADER_RESOLV
+
 m4_rename([AC_LANG_CALL], [saved_AC_LANG_CALL])
-m4_define([AC_LANG_CALL], [AC_LANG_PROGRAM([#include <resolv.h>],
+m4_define([AC_LANG_CALL], [AC_LANG_PROGRAM([#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#  include <netinet/in.h>   /* inet_ functions / structs */
+#endif
+#ifdef HAVE_ARPA_NAMESER_H
+#  include <arpa/nameser.h> /* DNS HEADER struct */
+#endif
+#ifdef HAVE_NETDB_H
+#  include <netdb.h>
+#endif
+#include <resolv.h>],
                                            [return res_ninit(NULL);])])
 AC_SEARCH_LIBS(res_ninit, resolv,
                AC_DEFINE(HAVE_RES_NINIT, 1,
@@ -130,8 +146,6 @@ AC_SEARCH_LIBS(getopt_long, iberty,
                AC_DEFINE(HAVE_GETOPT_LONG, 1,
                          [Define to 1 if you have the `getopt_long()' function.]))
 
-AC_HEADER_RESOLV
-
 #
 # Check for types
 #