Hi Eric,
Eric Blake wrote in
<http://lists.gnu.org/archive/html/bug-gnulib/2010-05/msg00135.html>:
> > I don't see how to test for a new vs. an old definition of AC_DEFUN_ONCE.
>
> You can use the existence of gnulib's witness macro (in 00gnulib.m4) as
> the proof of a working AC_DEFUN_ONCE prior to 2.64:
>
> m4_version_prereq([2.64],[AC_DEFUN_ONCE],
> [m4_ifdef([gl_00GNULIB],[AC_DEFUN_ONCE],[AC_DEFUN])])([AM_ICONV],
Thanks for the tip. I'm applying this:
2010-08-28 Bruno Haible <br...@clisp.org>
Prefer using AC_DEFUN_ONCE over AC_DEFUN in projects with gnulib.
* m4/iconv.m4 (gl_iconv_AC_DEFUN): Use AC_DEFUN_ONCE if gl_00GNULIB is
defined.
* m4/libunistring.m4 (gl_libunistring_AC_DEFUN): Likewise.
Suggested by Eric Blake.
--- m4/iconv.m4.orig Sat Aug 28 10:42:50 2010
+++ m4/iconv.m4 Sat Aug 28 10:36:48 2010
@@ -1,4 +1,4 @@
-# iconv.m4 serial 14 (gettext-0.18.2)
+# iconv.m4 serial 15 (gettext-0.18.2)
dnl Copyright (C) 2000-2002, 2007-2010 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -217,8 +217,11 @@
m4_version_prereq([2.64],
[[AC_DEFUN_ONCE(
[$1], [$2])]],
- [[AC_DEFUN(
- [$1], [$2])]]))
+ [m4_ifdef([gl_00GNULIB],
+ [[AC_DEFUN_ONCE(
+ [$1], [$2])]],
+ [[AC_DEFUN(
+ [$1], [$2])]])]))
gl_iconv_AC_DEFUN([AM_ICONV],
[
AM_ICONV_LINK
--- m4/libunistring.m4.orig Sat Aug 28 10:42:50 2010
+++ m4/libunistring.m4 Sat Aug 28 10:36:48 2010
@@ -1,4 +1,4 @@
-# libunistring.m4 serial 10
+# libunistring.m4 serial 11
dnl Copyright (C) 2009-2010 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -25,8 +25,11 @@
m4_version_prereq([2.64],
[[AC_DEFUN_ONCE(
[$1], [$2])]],
- [[AC_DEFUN(
- [$1], [$2])]]))
+ [m4_ifdef([gl_00GNULIB],
+ [[AC_DEFUN_ONCE(
+ [$1], [$2])]],
+ [[AC_DEFUN(
+ [$1], [$2])]])]))
gl_libunistring_AC_DEFUN([gl_LIBUNISTRING],
[
AC_BEFORE([$0], [gl_LIBUNISTRING_MODULE])
