Import from Autoconf sources:

2005-09-06  Paul Eggert  <eggert@cs.ucla.edu>
	* move-if-change: Don't output "$2 is unchanged"; suggested by Ben
	Elliston.  Handle weird characters correctly.

ChangeLog

@@ -1,3 +1,11 @@
+2005-09-07  Ben Elliston  <bje@au.ibm.com>
+
+	Import from Autoconf sources:
+
+	2005-09-06  Paul Eggert  <eggert@cs.ucla.edu>
+	* move-if-change: Don't output "$2 is unchanged"; suggested by Ben
+	Elliston.  Handle weird characters correctly.
+
 2005-08-30  Phil Edwards  <phil@codesourcery.com>
 
 	* configure.in (*-*-vxworks*):  Add target-libstdc++-v3 to noconfigdirs.

move-if-change

@@ -1,32 +1,22 @@
 #!/bin/sh
+# Like mv $1 $2, but if the files are the same, just delete $1.
+# Status is zero if successful, nonzero otherwise.
 
-# Copyright (C) 1996 Free Software Foundation, Inc.
+usage="$0: usage: $0 SOURCE DEST"
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
-if
+case $# in
-test -r $2
+2) ;;
-then
+*) echo "$usage" >&2; exit 1;;
-if
+esac
-cmp $1 $2 > /dev/null
+
-then
+for arg in "$1" "$2"; do
-echo $2 is unchanged
+  case $arg in
-rm -f $1
+   -*) echo "$usage" >&2; exit 1;;
+  esac
+done
+
+if test -r "$2" && cmp -s "$1" "$2"; then
+  rm -f "$1"
 else
-mv -f $1 $2
+  mv -f "$1" "$2"
-fi
-else
-mv -f $1 $2
 fi