/* Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <stdlib.h>

#include <string.h>

#include <wchar.h>

#include <gconv.h>

#include <wcsmbs/wcsmbsload.h>

/* Convert the multibyte character at S, which is no longer

   than N characters, to its `wchar_t' representation, placing

   this n *PWC and returning its length.

   Attention: this function should NEVER be intentionally used.

   The interface is completely stupid.  The state is shared between

   all conversion functions.  You should use instead the restartable

   version `mbrtowc'.  */

int

mbtowc (wchar_t *pwc, const char *s, size_t n)

{

  int result;

  static mbstate_t state;

  /* If S is NULL the function has to return null or not null

     depending on the encoding having a state depending encoding or

     not.  */

  if (s == NULL)

    {

      const struct gconv_fcts *fcts;

      /* Get the conversion functions.  */

      fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));

      /* This is an extension in the Unix standard which does not directly

	 violate ISO C.  */

      memset (&state, '\0', sizeof state);

      result = fcts->towc->__stateful;

    }

  else if (*s == '\0')

    {

      if (pwc != NULL)

	*pwc = L'\0';

      result = 0;

    }

  else

    {

      result = __mbrtowc (pwc, s, n, &state);

      /* The `mbrtowc' functions tell us more than we need.  Fold the -1

	 and -2 result into -1.  */

      if (result < 0)

	result = -1;

    }

  return result;

}