return 0;
errno = EILSEQ; return -1;
int mutt_wctoutf8 (char *s, unsigned int c){  if (c < (1 << 7))   {    if (s)      *s++ = c;    return 1;  }  else if (c < (1 << 11))  {    if (s)    {      *s++ = 0xc0 | (c >> 6);      *s++ = 0x80 | (c & 0x3f);    }    return 2;  }  else if (c < (1 << 16))  {    if (s)    {      *s++ = 0xe0 | (c >> 12);      *s++ = 0x80 | ((c >> 6) & 0x3f);      *s++ = 0x80 | (c & 0x3f);    }    return 3;  }  else if (c < (1 << 21))  {    if (s)    {      *s++ = 0xf0 | (c >> 18);      *s++ = 0x80 | ((c >> 12) & 0x3f);      *s++ = 0x80 | ((c >> 6) & 0x3f);      *s++ = 0x80 | (c & 0x3f);    }    return 4;  }  else if (c < (1 << 26))  {    if (s)    {      *s++ = 0xf8 | (c >> 24);      *s++ = 0x80 | ((c >> 18) & 0x3f);      *s++ = 0x80 | ((c >> 12) & 0x3f);      *s++ = 0x80 | ((c >> 6) & 0x3f);      *s++ = 0x80 | (c & 0x3f);    }    return 5;  }  else if (c < (1 << 31))  {    if (s)    {      *s++ = 0xfc | (c >> 30);      *s++ = 0x80 | ((c >> 24) & 0x3f);      *s++ = 0x80 | ((c >> 18) & 0x3f);      *s++ = 0x80 | ((c >> 12) & 0x3f);      *s++ = 0x80 | ((c >> 6) & 0x3f);      *s++ = 0x80 | (c & 0x3f);    }    return 6;  }  return 0;}