2006-04-01  Stepan Kasal  <address@hidden>

	* lib/m4sugar/m4sh.m4 (_AS_DIRNAME_PREPARE): New macro.
	(AS_DIRNAME): Use it.

Index: lib/m4sugar/m4sh.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/m4sugar/m4sh.m4,v
retrieving revision 1.170
diff -u -r1.170 m4sh.m4
--- lib/m4sugar/m4sh.m4	1 Apr 2006 19:38:07 -0000	1.170
+++ lib/m4sugar/m4sh.m4	1 Apr 2006 19:46:59 -0000
@@ -743,11 +743,23 @@
 	  s/.*/./; q']])
 
 m4_defun([AS_DIRNAME],
-[(dirname $1) 2>/dev/null ||
+[AS_REQUIRE([_$0_PREPARE])dnl
+$as_dirname $1 ||
 AS_DIRNAME_EXPR([$1]) 2>/dev/null ||
 AS_DIRNAME_SED([$1])])
 
 
+# _AS_DIRNAME_PREPARE
+# --------------------
+m4_defun([_AS_DIRNAME_PREPARE],
+[if (dirname /) >/dev/null 2>&1; then
+  as_dirname=dirname
+else
+  as_dirname=false
+fi
+])# _AS_DIRNAME_PREPARE
+
+
 # AS_EXECUTABLE_P
 # ---------------
 # Check whether a file is executable.