Update from gnulib (add comments, include stddef.h).

lib/safe-read.h

@@ -1,12 +1,25 @@
-#ifndef PARAMS
-# if defined PROTOTYPES || (defined __STDC__ && __STDC__)
-#  define PARAMS(Args) Args
-# else
-#  define PARAMS(Args) ()
-# endif
-#endif
+/* An interface to read() that retries after interrupts.
+   Copyright (C) 2002 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.  */
+
+#include <stddef.h>
 
 #define SAFE_READ_ERROR ((size_t) -1)
 
-size_t
-safe_read PARAMS ((int desc, void *ptr, size_t len));
+/* Read up to COUNT bytes at BUF from descriptor FD, retrying if interrupted.
+   Return the actual number of bytes read, zero for EOF, or SAFE_READ_ERROR
+   upon error.  */
+extern size_t safe_read (int fd, void *buf, size_t count);