diff --git a/ChangeLog b/ChangeLog
index 9bd7071099a..d4970f6fc79 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2008-03-16  Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
+
+	Backport from upstream Libtool:
+	
+	2007-10-12  Eric Blake  <ebb9@byu.net>
+	
+	Deal with Autoconf 2.62's semantic change in m4_append.
+	* ltsugar.m4 (lt_append): Replace broken versions of
+	m4_append.
+	(lt_if_append_uniq): Don't require separator to be overquoted,
+	and avoid broken m4_append.
+	(lt_dict_add): Fix typo.
+	* libtool.m4 (_LT_DECL): Don't overquote separator.
+
 2008-03-13  David Edelsohn  <edelsohn@gnu.org>
 
 	* config.rpath: Add AIX 6 support.
diff --git a/libtool.m4 b/libtool.m4
index e86cd0249b1..26a039a5a45 100644
--- a/libtool.m4
+++ b/libtool.m4
@@ -319,7 +319,7 @@ m4_bpatsubst([m4_bpatsubst([$1], [^ *], [# ])],
 # VALUE may be 0, 1 or 2 for a computed quote escaped value based on
 # VARNAME.  Any other value will be used directly.
 m4_define([_LT_DECL],
-[lt_if_append_uniq([lt_decl_varnames], [$2], [[, ]],
+[lt_if_append_uniq([lt_decl_varnames], [$2], [, ],
     [lt_dict_add_subkey([lt_decl_dict], [$2], [libtool_name],
 	[m4_ifval([$1], [$1], [$2])])
     lt_dict_add_subkey([lt_decl_dict], [$2], [value], [$3])
diff --git a/ltsugar.m4 b/ltsugar.m4
index fc51dc7e896..dd4f871ee96 100644
--- a/ltsugar.m4
+++ b/ltsugar.m4
@@ -1,13 +1,13 @@
 # ltsugar.m4 -- libtool m4 base layer.                         -*-Autoconf-*-
 #
-# Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+# Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
 # Written by Gary V. Vaughan.
 #
 # This file is free software; the Free Software Foundation gives
 # unlimited permission to copy and/or distribute it, with or without
 # modifications, as long as this notice is preserved.
 
-# serial 3 ltsugar.m4
+# serial 4 ltsugar.m4
 
 # This is to help aclocal find these macros, as it can't see m4_define.
 AC_DEFUN([LTSUGAR_VERSION], [m4_if([0.1])])
@@ -46,6 +46,20 @@ m4_define([lt_cdr],
 m4_define([lt_unquote], $1)
 
 
+# lt_append(MACRO-NAME, STRING, [SEPARATOR])
+# ------------------------------------------
+# Redefine MACRO-NAME to hold its former content plus `SEPARATOR'`STRING'.
+# Note that neither SEPARATOR nor STRING are expanded.  No SEPARATOR is
+# output if MACRO-NAME was previously undefined (different than defined
+# and empty).
+# This macro is needed until we can rely on Autoconf 2.62, since earlier
+# versions of m4 mistakenly expanded SEPARATOR.
+m4_define([lt_append],
+[m4_define([$1],
+	   m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
+
+
+
 # lt_combine(SEP, PREFIX-LIST, INFIX, SUFFIX1, [SUFFIX2...])
 # ----------------------------------------------------------
 # Produce a SEP delimited list of all paired combinations of elements of
@@ -67,10 +81,10 @@ m4_define([lt_combine],
 # by SEPARATOR if supplied) and expand UNIQ, else NOT-UNIQ.
 m4_define([lt_if_append_uniq],
 [m4_ifdef([$1],
-	[m4_bmatch($3[]m4_defn([$1])$3, $3[]m4_re_escape([$2])$3,
-		[$5],
-	    [m4_append([$1], [$2], [$3])$4])],
-    [m4_append([$1], [$2], [$3])$4])])
+	  [m4_if(m4_index([$3]m4_defn([$1])[$3], [$3$2$3]), [-1],
+		 [lt_append([$1], [$2], [$3])$4],
+		 [$5])],
+    [lt_append([$1], [$2], [$3])$4])])
 
 
 # lt_dict_add(DICT, KEY, VALUE)