include_next: port to autoconf 2.63

On RHEL 6.4 (using autoconf 2.63), './gnulib-tool --test math'
fails with the following, since commit 74540d44:
executing autoconf
configure:5693: error: possibly undefined macro: AS_VAR_COPY
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.

Since we document that we support out-of-the-box use with autoconf
2.59 and later, the fix is to provide a fallback definition.

* m4/gnulib-common.m4 (AS_VAR_COPY): Define if missing.

Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 580240a85bd8ec3e8b2d2379badfc13d7fe1d8e7)

diff --git a/ChangeLog b/ChangeLog
index 0f912d5..0f15302 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-01-06  Eric Blake  <eblake@redhat.com>
+
+       include_next: port to autoconf 2.63
+       * m4/gnulib-common.m4 (AS_VAR_COPY): Define if missing.
+
 2014-01-03  Paul Eggert  <eggert@cs.ucla.edu>
 
        doc: use ASCII in .texi files where UTF-8 isn't needed

diff --git a/NEWS.stable b/NEWS.stable
index 6845f55..2919f30 100644 (file)
--- a/NEWS.stable
+++ b/NEWS.stable
@@ -14,6 +14,7 @@ with the following additional commits:
     * [cfe23e8]->[79ca097] autoupdate
     * [5088dc5]->[7e54a06] manywarnings: remove -Wmudflap
     * [fe3419d]->[cd56634] doc: use ASCII in .texi files where UTF-8 isn't needed
+    * [580240a]->[] include_next: port to autoconf 2.63
 __NEXTCOMMITMARKER__
 
 ----------------------------------------------------------------------

diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index ae31e80..3b61b23 100644 (file)
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 33
+# gnulib-common.m4 serial 34
 dnl Copyright (C) 2007-2014 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -375,3 +375,7 @@ AC_DEFUN([gl_CACHE_VAL_SILENT],
   AC_CACHE_VAL([$1], [$2])
   as_echo_n="$saved_as_echo_n"
 ])
+
+# AS_VAR_COPY was added in autoconf 2.63b
+m4_define_default([AS_VAR_COPY],
+[AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])