diff --git a/ChangeLog b/ChangeLog
index 6ff46b4d..557b8b67 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2001-07-18  Akim Demaille  <akim@epita.fr>
+
+	* configure.in: Bump to 2.51a.
+
 2001-07-17  Akim Demaille  <akim@epita.fr>
 
 	Version 2.51.
diff --git a/Makefile.am b/Makefile.am
index 8ead9a1e..cb18cfec 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -66,8 +66,6 @@ CLEANFILES = autoconf.m4f \
 ## Maintainer rules.  ##
 ## ------------------ ##
 
-move_if_change = $(top_srcdir)/config/move-if-change
-
 ## acversion.m4.  ##
 
 # - acversion.m4 needs to be updated only once, since it depends on
@@ -137,37 +135,37 @@ autoconf: $(srcdir)/autoconf.in $(srcdir)/configure.ac
 	rm -f autoconf autoconf.tmp
 	$(edit) $(srcdir)/autoconf.in >autoconf.tmp
 	chmod +x autoconf.tmp
-	$(move_if_change) autoconf.tmp autoconf
+	mv autoconf.tmp autoconf
 
 autoheader: $(srcdir)/autoheader.in $(srcdir)/configure.ac
 	rm -f autoheader autoheader.tmp
 	$(edit) $(srcdir)/autoheader.in >autoheader.tmp
 	chmod +x autoheader.tmp
-	$(move_if_change) autoheader.tmp autoheader
+	mv autoheader.tmp autoheader
 
 autoreconf: $(srcdir)/autoreconf.in $(srcdir)/configure.ac
 	rm -f autoreconf autoreconf.tmp
 	$(edit) $(srcdir)/autoreconf.in >autoreconf.tmp
 	chmod +x autoreconf.tmp
-	$(move_if_change) autoreconf.tmp autoreconf
+	mv autoreconf.tmp autoreconf
 
 autoupdate: $(srcdir)/autoupdate.in $(srcdir)/configure.ac
 	rm -f autoupdate autoupdate.tmp
 	$(edit) $(srcdir)/autoupdate.in >autoupdate.tmp
 	chmod +x autoupdate.tmp
-	$(move_if_change) autoupdate.tmp autoupdate
+	mv autoupdate.tmp autoupdate
 
 ifnames: $(srcdir)/ifnames.in $(srcdir)/configure.ac
 	rm -f ifnames ifnames.tmp
 	$(edit) $(srcdir)/ifnames.in >ifnames.tmp
 	chmod +x ifnames.tmp
-	$(move_if_change) ifnames.tmp ifnames
+	mv ifnames.tmp ifnames
 
 autoscan: $(srcdir)/autoscan.in $(srcdir)/configure.ac
 	rm -f autoscan autoscan.tmp
 	$(edit) $(srcdir)/autoscan.in >autoscan.tmp
 	chmod +x autoscan.tmp
-	$(move_if_change) autoscan.tmp autoscan
+	mv autoscan.tmp autoscan
 
 
 ## ------------------ ##
diff --git a/Makefile.in b/Makefile.in
index c1cd66b3..8f5c28a8 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -101,8 +101,6 @@ EXTRA_DIST = ChangeLog.0 ChangeLog.1 ChangeLog.2              BUGS INSTALL.txt
 CLEANFILES = autoconf.m4f              $(bin_SCRIPTS)
 
 
-move_if_change = $(top_srcdir)/config/move-if-change
-
 # INSTALL is a special case.  Automake seems to have a single name space
 # for both targets and variables.  If we just use INSTALL, then the var
 # $(INSTALL) is not defined, and the install target fails.
@@ -132,7 +130,8 @@ SCRIPTS =  $(bin_SCRIPTS)
 DATA =  $(pkgdata_DATA)
 
 DIST_COMMON =  README AUTHORS COPYING ChangeLog INSTALL Makefile.am \
-Makefile.in NEWS THANKS TODO aclocal.m4 configure configure.ac
+Makefile.in NEWS README-alpha THANKS TODO aclocal.m4 configure \
+configure.ac
 
 
 DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) $(TEXINFOS) $(EXTRA_DIST)
@@ -457,37 +456,37 @@ autoconf: $(srcdir)/autoconf.in $(srcdir)/configure.ac
 	rm -f autoconf autoconf.tmp
 	$(edit) $(srcdir)/autoconf.in >autoconf.tmp
 	chmod +x autoconf.tmp
-	$(move_if_change) autoconf.tmp autoconf
+	mv autoconf.tmp autoconf
 
 autoheader: $(srcdir)/autoheader.in $(srcdir)/configure.ac
 	rm -f autoheader autoheader.tmp
 	$(edit) $(srcdir)/autoheader.in >autoheader.tmp
 	chmod +x autoheader.tmp
-	$(move_if_change) autoheader.tmp autoheader
+	mv autoheader.tmp autoheader
 
 autoreconf: $(srcdir)/autoreconf.in $(srcdir)/configure.ac
 	rm -f autoreconf autoreconf.tmp
 	$(edit) $(srcdir)/autoreconf.in >autoreconf.tmp
 	chmod +x autoreconf.tmp
-	$(move_if_change) autoreconf.tmp autoreconf
+	mv autoreconf.tmp autoreconf
 
 autoupdate: $(srcdir)/autoupdate.in $(srcdir)/configure.ac
 	rm -f autoupdate autoupdate.tmp
 	$(edit) $(srcdir)/autoupdate.in >autoupdate.tmp
 	chmod +x autoupdate.tmp
-	$(move_if_change) autoupdate.tmp autoupdate
+	mv autoupdate.tmp autoupdate
 
 ifnames: $(srcdir)/ifnames.in $(srcdir)/configure.ac
 	rm -f ifnames ifnames.tmp
 	$(edit) $(srcdir)/ifnames.in >ifnames.tmp
 	chmod +x ifnames.tmp
-	$(move_if_change) ifnames.tmp ifnames
+	mv ifnames.tmp ifnames
 
 autoscan: $(srcdir)/autoscan.in $(srcdir)/configure.ac
 	rm -f autoscan autoscan.tmp
 	$(edit) $(srcdir)/autoscan.in >autoscan.tmp
 	chmod +x autoscan.tmp
-	$(move_if_change) autoscan.tmp autoscan
+	mv autoscan.tmp autoscan
 
 # When processing the file with diversion disabled, there must be no
 # output but comments and empty lines.
diff --git a/Makefile.maint b/Makefile.maint
index c20f698d..e5e077d1 100644
--- a/Makefile.maint
+++ b/Makefile.maint
@@ -262,7 +262,7 @@ define emit-rsync-commands
 	echo =====================================
 endef
 
-$(xd-delta): $(release-archive-dir)/$(prev-tgz) $(distdir).tar.gz
+$(xd-delta): $(release_archive_dir)/$(prev-tgz) $(distdir).tar.gz
 	xdelta delta -9 $^ $@ || :
 
 alpha: local-check
diff --git a/NEWS b/NEWS
index 6c72883b..b25c1dfc 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,6 @@
-* Major changes in Autoconf 2.51                       -*- outline -*-
+* Major changes in Autoconf 2.51a                       -*- outline -*-
+[2.51]
+* Major changes in Autoconf 2.51
 ** Documentation
 - AC_ARG_VAR
 - Quadrigraphs
diff --git a/config/prev-version.txt b/config/prev-version.txt
index f02fc206..0dd46c96 100644
--- a/config/prev-version.txt
+++ b/config/prev-version.txt
@@ -1 +1 @@
-2.50
+2.51
diff --git a/configure b/configure
index 2f7cc048..da32fd56 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by Autoconf 2.50 for GNU Autoconf 2.51.
+# Generated by Autoconf 2.50 for GNU Autoconf 2.51a.
 #
 # Report bugs to <bug-autoconf@gnu.org>.
 #
@@ -146,8 +146,8 @@ mandir='${prefix}/man'
 # Identity of this package.
 PACKAGE_NAME='GNU Autoconf'
 PACKAGE_TARNAME='autoconf'
-PACKAGE_VERSION='2.51'
-PACKAGE_STRING='GNU Autoconf 2.51'
+PACKAGE_VERSION='2.51a'
+PACKAGE_STRING='GNU Autoconf 2.51a'
 PACKAGE_BUGREPORT='bug-autoconf@gnu.org'
 
 ac_prev=
@@ -535,7 +535,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<EOF
-\`configure' configures GNU Autoconf 2.51 to adapt to many kinds of systems.
+\`configure' configures GNU Autoconf 2.51a to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -597,7 +597,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of GNU Autoconf 2.51:";;
+     short | recursive ) echo "Configuration of GNU Autoconf 2.51a:";;
    esac
   cat <<\EOF
 
@@ -644,7 +644,7 @@ fi
 test -n "$ac_init_help" && exit 0
 if $ac_init_version; then
   cat <<\EOF
-GNU Autoconf configure 2.51
+GNU Autoconf configure 2.51a
 generated by GNU Autoconf 2.50
 
 Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001
@@ -659,7 +659,7 @@ cat >&5 <<EOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by GNU Autoconf $as_me 2.51, which was
+It was created by GNU Autoconf $as_me 2.51a, which was
 generated by GNU Autoconf 2.50.  Invocation command line was
 
   $ $0 $@
@@ -1077,7 +1077,7 @@ fi
 
 PACKAGE=autoconf
 
-VERSION=2.51
+VERSION=2.51a
 
 if test "`cd $srcdir && pwd`" != "`pwd`" && test -f $srcdir/config.status; then
   { { echo "$as_me:1083: error: source directory already configured; run \"make distclean\" there first" >&5
@@ -1620,7 +1620,7 @@ EOF
 
 cat >>$CONFIG_STATUS <<EOF
 ac_cs_version="\\
-GNU Autoconf config.status 2.51
+GNU Autoconf config.status 2.51a
 configured by $0, generated by GNU Autoconf 2.50,
   with options \\"`echo "$ac_configure_args" | sed 's/[\\""\`\$]/\\\\&/g'`\\"
 
@@ -1712,7 +1712,7 @@ cat >&5 << _ACEOF
 ## Running config.status.  ##
 ## ----------------------- ##
 
-This file was extended by $as_me (GNU Autoconf 2.51) 2.50, executed with
+This file was extended by $as_me (GNU Autoconf 2.51a) 2.50, executed with
   > $ac_cs_invocation
 on `(hostname || uname -n) 2>/dev/null | sed 1q`
 
@@ -2010,7 +2010,7 @@ if test "$no_create" != yes; then
 fi
 
 # Report the state of this version of Autoconf if this is a beta.
-case 2.51 in
+case 2.51a in
   *[a-z]*)
     cat <<EOF
 
diff --git a/configure.ac b/configure.ac
index 4bfb8594..ac1f4600 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,10 +1,10 @@
 #                                                       -*- Autoconf -*-
 # Process this file with autoconf to produce a configure script.
 AC_PREREQ(2.50)
-AC_INIT(GNU Autoconf, 2.51, bug-autoconf@gnu.org)
+AC_INIT(GNU Autoconf, 2.51a, bug-autoconf@gnu.org)
 AC_CONFIG_SRCDIR(acgeneral.m4)
 AC_CONFIG_AUX_DIR(config)
-AM_INIT_AUTOMAKE(autoconf, 2.51)
+AM_INIT_AUTOMAKE(autoconf, 2.51a)
 
 # Initialize the test suite.
 AT_CONFIG(..)
diff --git a/man/autoconf.1 b/man/autoconf.1
index 87d5c760..7f7ed137 100644
--- a/man/autoconf.1
+++ b/man/autoconf.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.24.
-.TH AUTOCONF "1" "July 2001" "GNU Autoconf 2.50d" FSF
+.TH AUTOCONF "1" "July 2001" "GNU Autoconf 2.51a" FSF
 .SH NAME
 autoconf \- Generate configuration scripts
 .SH SYNOPSIS
diff --git a/man/autoheader.1 b/man/autoheader.1
index 9caa173d..245d3d0a 100644
--- a/man/autoheader.1
+++ b/man/autoheader.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.24.
-.TH AUTOHEADER "1" "July 2001" "GNU Autoconf 2.50d" FSF
+.TH AUTOHEADER "1" "July 2001" "GNU Autoconf 2.51a" FSF
 .SH NAME
 autoheader \- Create a template header for configure
 .SH SYNOPSIS
diff --git a/man/autoreconf.1 b/man/autoreconf.1
index 96ad0eab..426c06e9 100644
--- a/man/autoreconf.1
+++ b/man/autoreconf.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.24.
-.TH AUTORECONF "1" "July 2001" "GNU Autoconf 2.50d" FSF
+.TH AUTORECONF "1" "July 2001" "GNU Autoconf 2.51a" FSF
 .SH NAME
 autoreconf \- Update generated configuration files
 .SH SYNOPSIS
diff --git a/man/autoscan.1 b/man/autoscan.1
index 429fdb08..c9fe89a0 100644
--- a/man/autoscan.1
+++ b/man/autoscan.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.24.
-.TH AUTOSCAN "1" "July 2001" "GNU Autoconf 2.50d" FSF
+.TH AUTOSCAN "1" "July 2001" "GNU Autoconf 2.51a" FSF
 .SH NAME
 autoscan \- Generate a preliminary configure.in
 .SH SYNOPSIS
diff --git a/man/autoupdate.1 b/man/autoupdate.1
index a925ac06..b4f1be28 100644
--- a/man/autoupdate.1
+++ b/man/autoupdate.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.24.
-.TH AUTOUPDATE "1" "July 2001" "GNU Autoconf 2.50d" FSF
+.TH AUTOUPDATE "1" "July 2001" "GNU Autoconf 2.51a" FSF
 .SH NAME
 autoupdate \- Update a configure.in to a newer Autoconf
 .SH SYNOPSIS
@@ -35,7 +35,7 @@ M4
 GNU M4 1.4 or above
 .TP
 AUTOCONF
-autoconf 2.50d
+autoconf 2.51a
 .SH AUTHOR
 Written by David J. MacKenzie and Akim Demaille.
 .PP
diff --git a/man/ifnames.1 b/man/ifnames.1
index cefe1ca3..0b077618 100644
--- a/man/ifnames.1
+++ b/man/ifnames.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.24.
-.TH IFNAMES "1" "July 2001" "GNU Autoconf 2.50d" FSF
+.TH IFNAMES "1" "July 2001" "GNU Autoconf 2.51a" FSF
 .SH NAME
 ifnames \- Extract CPP conditionals from a set of files
 .SH SYNOPSIS