From f0d75b778ee7bfd0feb368b51027943085a54705 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
Date: Fri, 26 Mar 2021 00:59:17 +0100
Subject: [PATCH 1/2] Add support for dns library without libinterface

BIND 9.16.12 and more recent have removed numeric versioning of library.
Instead it just contain complete text version. Extract numbers from it
and export it in similar manner.
---
 configure.ac | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index e8bce4abc..ca7ef188b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -90,19 +90,31 @@ AC_CHECK_LIB([krb5], [krb5_cc_initialize], [],
 AC_CHECK_LIB([uuid], [uuid_unparse], [],
 	AC_MSG_ERROR([Install UUID library development files]))
 
+AC_LANG(C)
 # Check version of libdns
 AC_MSG_CHECKING([libdns version])
-AC_TRY_RUN([
+AC_RUN_IFELSE([AC_LANG_PROGRAM([
 #include <stdio.h>
 #include <dns/version.h>
-int main(void) {
-	printf("%d\n", dns_libinterface);
-	return 0;
-}],[LIBDNS_VERSION_MAJOR=`./conftest$ac_exeext`
+],[ printf("%d\n", dns_libinterface) ])], [
+    LIBDNS_VERSION_MAJOR=`./conftest$ac_exeext`
+    AC_DEFINE_UNQUOTED([LIBDNS_VERSION_MAJOR], [$LIBDNS_VERSION_MAJOR],
+    [Define libdns version])], [
+    AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <stdio.h>
+#include <dns/version.h>
+]],[[
+	unsigned major, minor, patch, scanned;
+	/* emulate dns_libinterface from minor and patch version */
+        scanned = sscanf(dns_version, "%u.%u.%u", &major, &minor, &patch);
+        printf("%02d%02d\n", minor, patch);
+	return !(scanned == 3 && major == 9);
+    ]])], [
+    LIBDNS_VERSION_MAJOR=`./conftest$ac_exeext`
     AC_DEFINE_UNQUOTED([LIBDNS_VERSION_MAJOR], [$LIBDNS_VERSION_MAJOR],
     [Define libdns version])],
-[AC_MSG_ERROR([Can't obtain libdns version.])],
-[AC_MSG_ERROR([Cross compiling is not supported.])]
+    [AC_MSG_ERROR([Can't obtain libdns version.])])
+], [AC_MSG_ERROR([Cross compiling is not supported.])]
 )
 
 dnl isc_errno_toresult() was not available in older header files
-- 
2.26.2