removing asctime_r, ctime_r from the time_r module

[Paul Eggert]

I recently redisovered the fact that actime_r and ctime_r, like
asctime and ctime, are unsafe functions in the same sense that gets is
unsafe: they can overrun their output buffers and there's no simple
way for the user to detect in advance whether this will happen.  So
GNU apps shouldn't use these functions, and I propose that we remove
these function emulations from gnulib, as follows.  Any objections?

--- ../gnulib/lib/time_r.h      2005-07-11 04:21:55.000000000 -0700
+++ lib/time_r.h        2006-03-10 01:39:10.000000000 -0800
@@ -1,6 +1,6 @@
 /* Reentrant time functions like localtime_r.
 
-   Copyright (C) 2003, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2005, 2006 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
@@ -27,25 +27,20 @@
 #include <time.h>
 
 #if !HAVE_TIME_R_POSIX
-# undef asctime_r
-# undef ctime_r
+
+/* Don't bother with asctime_r and ctime_r, since these functions are
+   not safe (like asctime and ctime, they can overrun their 26-byte
+   output buffers when given outlandish struct tm values), and we
+   don't want to encourage applications to use unsafe functions.  Use
+   strftime or even sprintf instead.  */
+
 # undef gmtime_r
 # undef localtime_r
 
-# define asctime_r rpl_asctime_r
-# define ctime_r rpl_ctime_r
 # define gmtime_r rpl_gmtime_r
 # define localtime_r rpl_localtime_r
 
 /* See the POSIX:2001 specification
-   <http://www.opengroup.org/susv3xsh/asctime.html>.  */
-char *asctime_r (struct tm const * restrict, char * restrict);
-
-/* See the POSIX:2001 specification
-   <http://www.opengroup.org/susv3xsh/ctime.html>.  */
-char *ctime_r (time_t const *, char *);
-
-/* See the POSIX:2001 specification
    <http://www.opengroup.org/susv3xsh/gmtime.html>.  */
 struct tm *gmtime_r (time_t const * restrict, struct tm * restrict);
 
--- ../gnulib/lib/time_r.c      2005-09-19 10:28:15.000000000 -0700
+++ lib/time_r.c        2006-03-10 01:34:06.000000000 -0800
@@ -44,18 +44,6 @@ copy_tm_result (struct tm *dest, struct 
 }
 
 
-char *
-asctime_r (struct tm const * restrict tm, char * restrict buf)
-{
-  return copy_string_result (buf, asctime (tm));
-}
-
-char *
-ctime_r (time_t const *t, char *buf)
-{
-  return copy_string_result (buf, ctime (t));
-}
-
 struct tm *
 gmtime_r (time_t const * restrict t, struct tm * restrict tp)
 {