_AS_DIRNAME_PREPARE

diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 2c40e646a8785800c80a81a6a5f94b08776fe503..efb1518eb86f997b123e649d73e78ce3630ad8f3 100644 (file)
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -743,11 +743,23 @@ m4_defun([AS_DIRNAME_SED],
          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.