head bootstrap improvement

[Eric Blake]

This patch relaxes things so you can once again bootstrap CVS head using M4 
1.4.3 as the installed version.

2006-11-16  Eric Blake  <address@hidden>

        * bootstrap: Relax m4 requirement, thanks to...
        * configure.ac (Gettext support): ...this workaround to the 1.4.4
        bug.  Undoes restriction added on 2006-11-09.

Index: bootstrap
===================================================================
RCS file: /sources/m4/m4/bootstrap,v
retrieving revision 1.43
diff -u -r1.43 bootstrap
--- bootstrap   9 Nov 2006 16:39:15 -0000       1.43
+++ bootstrap   16 Nov 2006 18:58:59 -0000
@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# bootstrap (GNU M4) version 2006-11-09
+# bootstrap (GNU M4) version 2006-11-16
 # Written by Gary V. Vaughan  <address@hidden>
 
 # Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
@@ -39,7 +39,7 @@
 
 # This script bootstraps a CVS checkout of GNU M4 by correctly calling
 # out to parts of the GNU Build Platform.  Currently this requires GNU
-# Gettext 0.16 or better, Autoconf 2.60 or better, GNU M4 1.4.5 or
+# Gettext 0.16 or better, Autoconf 2.60 or better, GNU M4 1.4.x or
 # better, a CVS snapshot of Automake 1.10a or better, a CVS snapshot
 # of Libtool 2.1a or better, and the latest CVS checkout of Gnulib.
 # Libtool must be installed; either with the same --prefix as
@@ -246,14 +246,6 @@
   fi
 }
 
-## ---------------------------------------------- ##
-## Test that the installed M4 is powerful enough. ##
-## M4 1.4.4 and earlier are insufficient.         ##
-## ---------------------------------------------- ##
-if test -n "`echo 'ifdef(mac,bug)dnl' | $M4 --trace=mac`" ; then
-  func_fatal_error "Bootstrapping requires installed GNU M4 1.4.5 or greater."
-fi
-
 ## ------------------------------ ##
 ## Fetch translations.            ##
 ## (taken from GNU tar bootstrap) ##
Index: configure.ac
===================================================================
RCS file: /sources/m4/m4/configure.ac,v
retrieving revision 1.61
diff -u -r1.61 configure.ac
--- configure.ac        31 Oct 2006 02:05:37 -0000      1.61
+++ configure.ac        16 Nov 2006 18:58:59 -0000
@@ -144,6 +144,18 @@
 ## ---------------- ##
 ## Gettext support. ##
 ## ---------------- ##
+dnl M4 1.4.4 and earlier had a bug that tracing a macro made it falsely
+dnl appear as defined with an empty definition, even though `invoking'
+dnl the macro resulted in the macro name.  Gettext relies on whether
+dnl AM_GNU_GETTEXT_INTL_SUBDIR is defined, and automake traces this
+dnl macro, but we don't want to use an intl subdir, hence this workaround
+dnl to allow bootstrapping even on systems with old M4.
+dnl http://lists.gnu.org/archive/html/bug-gnu-utils/2006-11/msg00096.html
+m4_ifdef([AM_GNU_GETTEXT_INTL_SUBDIR],
+  [m4_if(m4_defn([AM_GNU_GETTEXT_INTL_SUBDIR]),[],
+    [m4_ifval(AM_GNU_GETTEXT_INTL_SUBDIR,
+      [m4_popdef([AM_GNU_GETTEXT_INTL_SUBDIR])])])])
+
 AM_GNU_GETTEXT([external], [need-formatstring-macros])
 AM_GNU_GETTEXT_VERSION([0.16])
 M4_GNU_GETTEXT