Include copyright notice.

(cu_PREREQ_STAT_PROG): Use the _ONCE variants when appropriate.
Include sys/param.h before testing for sys/mount.h.

m4/stat-prog.m4

@@ -1,11 +1,33 @@
-#serial 1
+# stat-prog.m4 serial 2
 # Record the prerequisites of src/stat.c from the coreutils package.
 
+# Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+# Written by Jim Meyering.
+
 AC_DEFUN([cu_PREREQ_STAT_PROG],
 [
-  AC_CHECK_HEADERS(sys/sysmacros.h sys/statvfs.h sys/vfs.h)
-  AC_CHECK_HEADERS(sys/param.h sys/mount.h)
-  AC_CHECK_FUNCS(statvfs)
+  AC_CHECK_HEADERS_ONCE(sys/param.h sys/sysmacros.h sys/statvfs.h sys/vfs.h)
+  AC_CHECK_HEADERS(sys/mount.h, [], [],
+    [AC_INCLUDES_DEFAULT
+     [#if HAVE_SYS_PARAM_H
+       #include <sys/param.h>
+      #endif]))
+  AC_CHECK_FUNCS_ONCE(statvfs)
 
   # For `struct statfs' on Ultrix 4.4.
   AC_CHECK_HEADERS([netinet/in.h nfs/nfs_clnt.h nfs/vfs.h],,,