2005-08-22  Stepan Kasal  <address@hidden>

	* lib/autoconf/general.m4 (_AC_CANONICAL_SPLIT): Simplify; rejecting
	some evil values and relying on the fact that $* concatenates the
	parameters by the first character from IFS.

Index: lib/autoconf/general.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autoconf/general.m4,v
retrieving revision 1.880
diff -u -r1.880 general.m4
--- lib/autoconf/general.m4	16 Aug 2005 09:11:06 -0000	1.880
+++ lib/autoconf/general.m4	22 Aug 2005 15:57:02 -0000
@@ -1655,23 +1655,20 @@
 # --------------------------
 # Generate the variables THING, THING_{alias cpu vendor os}.
 m4_define([_AC_CANONICAL_SPLIT],
-[AC_SUBST([$1],       [$ac_cv_$1])dnl
+[# Ensure that the following "set" and "shift" commands will not fail:
+case $ac_cv_$1 in
+  -*) false ;;
+  *-*-*) : ;;
+  *) false ;;
+esac || AC_MSG_ERROR([invalid value of canonical $1])
+AC_SUBST([$1], [$ac_cv_$1])dnl
 ac_save_IFS=$IFS; IFS='-'
-set x $ac_cv_$1
-shift
-IFS=$ac_save_IFS
-
+set $ac_cv_$1
 AC_SUBST([$1_cpu], [$[1]])dnl
 AC_SUBST([$1_vendor], [$[2]])dnl
-AC_SUBST([$1_os], [$[3]])dnl
-case $[#] in
-0|1|2) ;;
-*)
-  shift; shift; shift
-  for ac_arg
-  do $1_os=[$]$1_os-$ac_arg
-  done;;
-esac
+shift; shift
+AC_SUBST([$1_os], [$[*]])dnl
+IFS=$ac_save_IFS
 ])# _AC_CANONICAL_SPLIT