1  /* Convert multibyte character to wide character.
       2     Copyright (C) 2011-2021 Free Software Foundation, Inc.
       3     Written by Bruno Haible <bruno@clisp.org>, 2011.
       4  
       5     This program is free software: you can redistribute it and/or modify
       6     it under the terms of the GNU General Public License as published by
       7     the Free Software Foundation; either version 3 of the License, or
       8     (at your option) any later version.
       9  
      10     This program is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13     GNU General Public License for more details.
      14  
      15     You should have received a copy of the GNU General Public License
      16     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  /* We don't need a static internal state, because the encoding is not state
      19     dependent, and when mbrtowc returns (size_t)(-2). we throw the result
      20     away. */
      21  
      22  int
      23  mbtowc (wchar_t *pwc, const char *s, size_t n)
      24  {
      25    if (s == NULL)
      26      return 0;
      27    else
      28      {
      29        mbstate_t state;
      30        wchar_t wc;
      31        size_t result;
      32  
      33        memset (&state, 0, sizeof (mbstate_t));
      34        result = mbrtowc (&wc, s, n, &state);
      35        if (result == (size_t)-1 || result == (size_t)-2)
      36          {
      37            errno = EILSEQ;
      38            return -1;
      39          }
      40        if (pwc != NULL)
      41          *pwc = wc;
      42        return (wc == 0 ? 0 : result);
      43      }
      44  }