X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Futime.m4;h=f090e7b048479fbeb5b20d07743faa477e03ee45;hb=4097b52187106b6a2940d28968cfecd4e53f9b4e;hp=26b5ea90a78213e2314959d596344b7e319335aa;hpb=42d1eda5dcce2d68deab7a642e7f29bcd7144a0d;p=gnulib.git

diff --git a/m4/utime.m4 b/m4/utime.m4
index 26b5ea90a..f090e7b04 100644
--- a/m4/utime.m4
+++ b/m4/utime.m4
@@ -1,4 +1,4 @@
-# serial 8
+# serial 9
 
 dnl From Jim Meyering
 dnl Replace the utime function on systems that need it.
@@ -28,3 +28,34 @@ AC_DEFUN([gl_PREREQ_UTIME],
   AC_REQUIRE([gl_CHECK_TYPE_STRUCT_UTIMBUF])
   gl_FUNC_UTIMES_NULL
 ])
+
+# Use the definition of AC_FUNC_UTIME_NULL from autoconf 2.64 or newer.
+# Remove this macro when we can assume autoconf >= 2.64.
+m4_version_prereq([2.64], [], [
+AC_DEFUN([AC_FUNC_UTIME_NULL],
+[AC_CHECK_HEADERS_ONCE([utime.h])
+AC_CACHE_CHECK([whether utime accepts a null argument], [ac_cv_func_utime_null],
+[rm -f conftest.data; >conftest.data
+# Sequent interprets utime(file, 0) to mean use start of epoch.  Wrong.
+AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
+	       #ifdef HAVE_UTIME_H
+	       # include <utime.h>
+	       #endif],
+[[struct stat s, t;
+  return ! (stat ("conftest.data", &s) == 0
+	    && utime ("conftest.data", 0) == 0
+	    && stat ("conftest.data", &t) == 0
+	    && t.st_mtime >= s.st_mtime
+	    && t.st_mtime - s.st_mtime < 120);]])],
+	      ac_cv_func_utime_null=yes,
+	      ac_cv_func_utime_null=no,
+	      ac_cv_func_utime_null='guessing yes')])
+if test "x$ac_cv_func_utime_null" != xno; then
+  ac_cv_func_utime_null=yes
+  AC_DEFINE([HAVE_UTIME_NULL], [1],
+	    [Define to 1 if `utime(file, NULL)' sets file's timestamp to the
+	     present.])
+fi
+rm -f conftest.data
+])
+])