Patch taken upstream at
http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=7f75858f577f11a844781764f30cd42cfe8a5669,
with the following modifications:

 * Changes to NEWS file removed to avoid conflicts

 * Changes also made manually to the generated configure
   script. Otherwise, host-autoconf is needed to compile
   host-autoconf !

Index: autoconf-2.65.old/configure
===================================================================
--- autoconf-2.65.old.orig/configure	2009-12-15 16:11:05.175566911 +0100
+++ autoconf-2.65.old/configure	2009-12-15 16:11:37.739562146 +0100
@@ -2380,7 +2380,7 @@
       ac_snippet=change'quote(<,>)in''dir(<if''def>,mac,bug)'
       ac_snippet=${ac_snippet}pat'subst(a,\(b\)\|\(a\),\1)d'nl
       test -z "`$ac_path_M4 -F conftest.m4f </dev/null 2>&1`" \
-      && test -z "`echo $ac_snippet | $ac_path_M4 --trace=mac 2>&1`" \
+      && test -z "`$as_echo $ac_snippet | $ac_path_M4 --trace=mac 2>&1`" \
       && test -f conftest.m4f \
       && ac_cv_path_M4=$ac_path_M4 ac_path_M4_found=:
       rm -f conftest.m4f
Index: autoconf-2.65.old/m4/m4.m4
===================================================================
--- autoconf-2.65.old.orig/m4/m4.m4	2009-12-15 16:11:05.207566124 +0100
+++ autoconf-2.65.old/m4/m4.m4	2009-12-15 16:11:18.595562030 +0100
@@ -29,7 +29,7 @@
       ac_snippet=change'quote(<,>)in''dir(<if''def>,mac,bug)'
       ac_snippet=${ac_snippet}pat'subst(a,\(b\)\|\(a\),\1)d'nl
       test -z "`$ac_path_M4 -F conftest.m4f </dev/null 2>&1`" \
-      && test -z "`echo $ac_snippet | $ac_path_M4 --trace=mac 2>&1`" \
+      && test -z "`AS_ECHO([$ac_snippet]) | $ac_path_M4 --trace=mac 2>&1`" \
       && test -f conftest.m4f \
       && ac_cv_path_M4=$ac_path_M4 ac_path_M4_found=:
       rm -f conftest.m4f],