/*	$OpenBSD: duplocale.c,v 1.1 2017/09/05 03:16:13 schwarze Exp $ */
/*
 * Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <errno.h>
#include <locale.h>

#include "rune.h"

locale_t
duplocale(locale_t oldloc)
{
	if (oldloc == _LOCALE_UTF8 && _Utf8RuneLocale != NULL)
		return _LOCALE_UTF8;
	if (oldloc == _LOCALE_C)
		return _LOCALE_C;
	if (oldloc == LC_GLOBAL_LOCALE)
		return _GlobalRuneLocale == _Utf8RuneLocale ?
		    _LOCALE_UTF8 : _LOCALE_C;

	/* POSIX says: invalid input -> undefined behaviour. */
	errno = EINVAL;
	return _LOCALE_NONE;
}