$NetBSD: patch-ab,v 1.5 2015/03/18 17:46:32 dholland Exp $

First chunk: automake-1.13 compat.
Second chunk: use pkgsrc libltdl
Third chunk (about dtoa): ? (XXX)
Fourth chunk: fix detection of isnan

--- configure.ac.orig	2008-02-10 10:31:33.000000000 +0000
+++ configure.ac
@@ -5,7 +5,7 @@ AC_INIT([see],
 	[leonard@users.sourceforge.net])
 AC_PREREQ(2.52)
 AM_INIT_AUTOMAKE
-AM_CONFIG_HEADER(include/config.h)
+AC_CONFIG_HEADERS(include/config.h)
 AC_CONFIG_FILES([Makefile
 		 include/Makefile
 		 include/see/Makefile
@@ -29,11 +29,11 @@ dnl
 AC_PROG_CC
 AC_PROG_SED
 
-AC_LIBLTDL_CONVENIENCE([libltdl])
 AC_LIBTOOL_DLOPEN
 AC_PROG_LIBTOOL
 dnl AC_LIB_LTDL
-AC_CONFIG_SUBDIRS([libltdl])
+LIBLTDL=-lltdl
+LTDLINCL=
 AC_SUBST([LIBLTDL])
 AC_SUBST([LTDLINCL])
 AC_SUBST([LIBSEE_LIBS])
@@ -206,11 +206,12 @@ SEE_ARG_ENABLE(longjmperror,[yes],
         [Define if you want SEE to catch longjmp corruption])
 ])
 
-SEE_ARG_ENABLE(native-dtoa,[auto],
+SEE_ARG_ENABLE(native-dtoa,[no],
     [dtoa from libc],
-    [enable_native_dtoa=yes
-     AC_CHECK_FUNCS([strtod dtoa freedtoa],,[enable_native_dtoa=no])
-])
+    [],
+    [enable_native_dtoa=yes],
+    [enable_native_dtoa=no]
+)
 AM_CONDITIONAL(NATIVE_DTOA, test x"$enable_native_dtoa" = x"yes")
 
 
@@ -333,6 +334,10 @@ AC_CHECK_FUNCS([isnan _isnan],[have_isna
 AC_CHECK_FUNCS([finite _finite isfinite],[have_finite=yes])
 AC_CHECK_FUNCS([copysign _copysign],[have_copysign=yes])
 
+if test $have_isnan = no; then
+    AC_CHECK_DECLS([isnan],[have_isnan=yes],,[#include <math.h>])
+fi
+
 dnl -- when using double isnan/finite must be available
 if test $ac_cv_sizeof_float -ne 8; then
     test $have_isnan = no && missing_funcs="$missing_funcs isnan";