Re: iconv.m4: avoid warning

[Bruno Haible]

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  <address@hidden>

        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])