1 files changed, 17 insertions, 2 deletions

diff --git a/gl/m4/iconv.m4 b/gl/m4/iconv.m4
index f46ff142..e2041b9b 100644
--- a/gl/m4/iconv.m4
+++ b/gl/m4/iconv.m4
@@ -1,4 +1,4 @@
-# iconv.m4 serial 9 (gettext-0.18)
+# iconv.m4 serial 11 (gettext-0.18.1)
 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,
@@ -170,7 +170,22 @@ int main ()
   AC_SUBST([LTLIBICONV])
 ])
 
-AC_DEFUN([AM_ICONV],
+dnl Define AM_ICONV using AC_DEFUN_ONCE for Autoconf >= 2.64, in order to
+dnl avoid warnings like
+dnl "warning: AC_REQUIRE: `AM_ICONV' was expanded before it was required".
+dnl This is tricky because of the way 'aclocal' is implemented:
+dnl - It requires defining an auxiliary macro whose name ends in AC_DEFUN.
+dnl   Otherwise aclocal's initial scan pass would miss the macro definition.
+dnl - It requires a line break inside the AC_DEFUN_ONCE and AC_DEFUN expansions.
+dnl   Otherwise aclocal would emit many "Use of uninitialized value $1"
+dnl   warnings.
+m4_define([gl_iconv_AC_DEFUN],
+  m4_version_prereq([2.64],
+    [[AC_DEFUN_ONCE(
+        [$1], [$2])]],
+    [[AC_DEFUN(
+        [$1], [$2])]]))
+gl_iconv_AC_DEFUN([AM_ICONV],
 [
   AM_ICONV_LINK
   if test "$am_cv_func_iconv" = yes; then