/src/CMake/Utilities/cmlibarchive/libarchive/archive_string.c

Source
/*-
 * Copyright (c) 2003-2011 Tim Kientzle
 * Copyright (c) 2011-2012 Michihiro NAKAJIMA
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "archive_platform.h"

/*
 * Basic resizable string support, to simplify manipulating arbitrary-sized
 * strings while minimizing heap activity.
 *
 * In particular, the buffer used by a string object is only grown, it
 * never shrinks, so you can clear and reuse the same string object
 * without incurring additional memory allocations.
 */

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_ICONV_H
#include <iconv.h>
#endif
#ifdef HAVE_LANGINFO_H
#include <langinfo.h>
#endif
#ifdef HAVE_LOCALCHARSET_H
#include <localcharset.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_WCHAR_H
#include <wchar.h>
#endif
#if defined(_WIN32) && !defined(__CYGWIN__)
#include <windows.h>
#include <locale.h>
#endif

#include "archive_endian.h"
#include "archive_private.h"
#include "archive_string.h"
#include "archive_string_composition.h"

#if !defined(HAVE_WMEMCPY) && !defined(wmemcpy)
#define wmemcpy(a,b,i)  (wchar_t *)memcpy((a), (b), (i) * sizeof(wchar_t))
#endif

#if !defined(HAVE_WMEMMOVE) && !defined(wmemmove)
#define wmemmove(a,b,i)  (wchar_t *)memmove((a), (b), (i) * sizeof(wchar_t))
#endif

#undef max
#define max(a, b)       ((a)>(b)?(a):(b))

struct archive_string_conv {
  struct archive_string_conv  *next;
  char        *from_charset;
  char        *to_charset;
  unsigned       from_cp;
  unsigned       to_cp;
  /* Set 1 if from_charset and to_charset are the same. */
  int        same;
  int        flag;
#define SCONV_TO_CHARSET  1  /* MBS is being converted to specified
           * charset. */
#define SCONV_FROM_CHARSET  (1<<1)  /* MBS is being converted from
           * specified charset. */
#define SCONV_BEST_EFFORT   (1<<2)  /* Copy at least ASCII code. */
#define SCONV_WIN_CP    (1<<3)  /* Use Windows API for converting
           * MBS. */
#define SCONV_UTF8_LIBARCHIVE_2 (1<<4)  /* Incorrect UTF-8 made by libarchive
           * 2.x in the wrong assumption. */
#define SCONV_NORMALIZATION_C (1<<6)  /* Need normalization to be Form C.
           * Before UTF-8 characters are actually
           * processed. */
#define SCONV_NORMALIZATION_D (1<<7)  /* Need normalization to be Form D.
           * Before UTF-8 characters are actually
           * processed.
           * Currently this only for MAC OS X. */
#define SCONV_TO_UTF8   (1<<8)  /* "to charset" side is UTF-8. */
#define SCONV_FROM_UTF8   (1<<9)  /* "from charset" side is UTF-8. */
#define SCONV_TO_UTF16BE  (1<<10)  /* "to charset" side is UTF-16BE. */
#define SCONV_FROM_UTF16BE  (1<<11)  /* "from charset" side is UTF-16BE. */
#define SCONV_TO_UTF16LE  (1<<12)  /* "to charset" side is UTF-16LE. */
#define SCONV_FROM_UTF16LE  (1<<13)  /* "from charset" side is UTF-16LE. */
#define SCONV_TO_UTF16    (SCONV_TO_UTF16BE | SCONV_TO_UTF16LE)
#define SCONV_FROM_UTF16  (SCONV_FROM_UTF16BE | SCONV_FROM_UTF16LE)

#if HAVE_ICONV
  iconv_t        cd;
  iconv_t        cd_w;/* Use at archive_mstring on
                 * Windows. */
#endif
  /* A temporary buffer for normalization. */
  struct archive_string    utftmp;
  int (*converter[2])(struct archive_string *, const void *, size_t,
      struct archive_string_conv *);
  int        nconverter;
};

#define CP_C_LOCALE 0 /* "C" locale only for this file. */
#define CP_UTF16LE  1200
#define CP_UTF16BE  1201

#define IS_HIGH_SURROGATE_LA(uc) ((uc) >= 0xD800 && (uc) <= 0xDBFF)
#define IS_LOW_SURROGATE_LA(uc)  ((uc) >= 0xDC00 && (uc) <= 0xDFFF)
#define IS_SURROGATE_PAIR_LA(uc) ((uc) >= 0xD800 && (uc) <= 0xDFFF)
#define UNICODE_MAX   0x10FFFF
#define UNICODE_R_CHAR    0xFFFD  /* Replacement character. */
/* Set U+FFFD(Replacement character) in UTF-8. */
static const char utf8_replacement_char[] = {0xef, 0xbf, 0xbd};

static struct archive_string_conv *find_sconv_object(struct archive *,
  const char *, const char *);
static void add_sconv_object(struct archive *, struct archive_string_conv *);
static struct archive_string_conv *create_sconv_object(const char *,
  const char *, unsigned, int);
static void free_sconv_object(struct archive_string_conv *);
static struct archive_string_conv *get_sconv_object(struct archive *,
  const char *, const char *, int);
static unsigned make_codepage_from_charset(const char *);
static unsigned get_current_codepage(void);
static unsigned get_current_oemcp(void);
static size_t mbsnbytes(const void *, size_t);
static size_t utf16nbytes(const void *, size_t);
#if defined(_WIN32) && !defined(__CYGWIN__)
static int archive_wstring_append_from_mbs_in_codepage(
    struct archive_wstring *, const char *, size_t,
    struct archive_string_conv *);
static int archive_string_append_from_wcs_in_codepage(struct archive_string *,
    const wchar_t *, size_t, struct archive_string_conv *);
static int strncat_in_codepage(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int win_strncat_from_utf16be(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int win_strncat_from_utf16le(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int win_strncat_to_utf16be(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int win_strncat_to_utf16le(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
#endif
static int best_effort_strncat_from_utf16be(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);
static int best_effort_strncat_from_utf16le(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);
static int best_effort_strncat_to_utf16be(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);
static int best_effort_strncat_to_utf16le(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);
#if defined(HAVE_ICONV)
static int iconv_strncat_in_locale(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
#endif
static int best_effort_strncat_in_locale(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);
static int _utf8_to_unicode(uint32_t *, const char *, size_t);
static int utf8_to_unicode(uint32_t *, const char *, size_t);
static inline uint32_t combine_surrogate_pair(uint32_t, uint32_t);
static int cesu8_to_unicode(uint32_t *, const char *, size_t);
static size_t unicode_to_utf8(char *, size_t, uint32_t);
static int utf16_to_unicode(uint32_t *, const char *, size_t, int);
static size_t unicode_to_utf16be(char *, size_t, uint32_t);
static size_t unicode_to_utf16le(char *, size_t, uint32_t);
static int strncat_from_utf8_libarchive2(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);
static int strncat_from_utf8_to_utf8(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int archive_string_normalize_C(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int archive_string_normalize_D(struct archive_string *, const void *,
    size_t, struct archive_string_conv *);
static int archive_string_append_unicode(struct archive_string *,
    const void *, size_t, struct archive_string_conv *);

#if defined __LITTLE_ENDIAN__
  #define IS_BIG_ENDIAN 0
#elif defined __BIG_ENDIAN__
  #define IS_BIG_ENDIAN 1
#elif defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
  #define IS_BIG_ENDIAN 0
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
  #define IS_BIG_ENDIAN 1
#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || defined(_M_ARM64))
  #define IS_BIG_ENDIAN 0
#else
// Detect endianness at runtime.
static int
is_big_endian(void)
{
  uint16_t d = 1;

  return (archive_be16dec(&d) == 1);
}

#define IS_BIG_ENDIAN is_big_endian()
#endif

static struct archive_string *
archive_string_append(struct archive_string *as, const char *p, size_t s)
{
  if (archive_string_ensure(as, as->length + s + 1) == NULL)
    return (NULL);
  if (s)
    memmove(as->s + as->length, p, s);
  as->length += s;
  as->s[as->length] = 0;
  return (as);
}

static struct archive_wstring *
archive_wstring_append(struct archive_wstring *as, const wchar_t *p, size_t s)
{
  if (archive_wstring_ensure(as, as->length + s + 1) == NULL)
    return (NULL);
  if (s)
    wmemmove(as->s + as->length, p, s);
  as->length += s;
  as->s[as->length] = 0;
  return (as);
}

struct archive_string *
archive_array_append(struct archive_string *as, const char *p, size_t s)
{
  return archive_string_append(as, p, s);
}

void
archive_string_concat(struct archive_string *dest, struct archive_string *src)
{
  if (archive_string_append(dest, src->s, src->length) == NULL)
    __archive_errx(1, "Out of memory");
}

void
archive_wstring_concat(struct archive_wstring *dest,
    struct archive_wstring *src)
{
  if (archive_wstring_append(dest, src->s, src->length) == NULL)
    __archive_errx(1, "Out of memory");
}

void
archive_string_free(struct archive_string *as)
{
  as->length = 0;
  as->buffer_length = 0;
  free(as->s);
  as->s = NULL;
}

void
archive_wstring_free(struct archive_wstring *as)
{
  as->length = 0;
  as->buffer_length = 0;
  free(as->s);
  as->s = NULL;
}

struct archive_wstring *
archive_wstring_ensure(struct archive_wstring *as, size_t s)
{
  return (struct archive_wstring *)
    archive_string_ensure((struct archive_string *)as,
          s * sizeof(wchar_t));
}

/* Returns NULL on any allocation failure. */
struct archive_string *
archive_string_ensure(struct archive_string *as, size_t s)
{
  char *p;
  size_t new_length;

  /* If buffer is already big enough, don't reallocate. */
  if (as->s && (s <= as->buffer_length))
    return (as);

  /*
   * Growing the buffer at least exponentially ensures that
   * append operations are always linear in the number of
   * characters appended.  Using a smaller growth rate for
   * larger buffers reduces memory waste somewhat at the cost of
   * a larger constant factor.
   */
  if (as->buffer_length < 32)
    /* Start with a minimum 32-character buffer. */
    new_length = 32;
  else if (as->buffer_length < 8192)
    /* Buffers under 8k are doubled for speed. */
    new_length = as->buffer_length + as->buffer_length;
  else {
    /* Buffers 8k and over grow by at least 25% each time. */
    new_length = as->buffer_length + as->buffer_length / 4;
    /* Be safe: If size wraps, fail. */
    if (new_length < as->buffer_length) {
      /* On failure, wipe the string and return NULL. */
      archive_string_free(as);
      errno = ENOMEM;/* Make sure errno has ENOMEM. */
      return (NULL);
    }
  }
  /*
   * The computation above is a lower limit to how much we'll
   * grow the buffer.  In any case, we have to grow it enough to
   * hold the request.
   */
  if (new_length < s)
    new_length = s;
  /* Now we can reallocate the buffer. */
  p = realloc(as->s, new_length);
  if (p == NULL) {
    /* On failure, wipe the string and return NULL. */
    archive_string_free(as);
    errno = ENOMEM;/* Make sure errno has ENOMEM. */
    return (NULL);
  }

  as->s = p;
  as->buffer_length = new_length;
  return (as);
}

/*
 * TODO: See if there's a way to avoid scanning
 * the source string twice.  Then test to see
 * if it actually helps (remember that we're almost
 * always called with pretty short arguments, so
 * such an optimization might not help).
 */
struct archive_string *
archive_strncat(struct archive_string *as, const void *_p, size_t n)
{
  size_t s;
  const char *p, *pp;

  p = (const char *)_p;

  /* Like strlen(p), except won't examine positions beyond p[n]. */
  s = 0;
  pp = p;
  while (s < n && *pp) {
    pp++;
    s++;
  }
  if ((as = archive_string_append(as, p, s)) == NULL)
    __archive_errx(1, "Out of memory");
  return (as);
}

struct archive_wstring *
archive_wstrncat(struct archive_wstring *as, const wchar_t *p, size_t n)
{
  size_t s;
  const wchar_t *pp;

  /* Like strlen(p), except won't examine positions beyond p[n]. */
  s = 0;
  pp = p;
  while (s < n && *pp) {
    pp++;
    s++;
  }
  if ((as = archive_wstring_append(as, p, s)) == NULL)
    __archive_errx(1, "Out of memory");
  return (as);
}

struct archive_string *
archive_strcat(struct archive_string *as, const void *p)
{
  /* strcat is just strncat without an effective limit. 
   * Assert that we'll never get called with a source
   * string over 16MB.
   * TODO: Review all uses of strcat in the source
   * and try to replace them with strncat().
   */
  return archive_strncat(as, p, 0x1000000);
}

struct archive_wstring *
archive_wstrcat(struct archive_wstring *as, const wchar_t *p)
{
  /* Ditto. */
  return archive_wstrncat(as, p, 0x1000000);
}

struct archive_string *
archive_strappend_char(struct archive_string *as, char c)
{
  if ((as = archive_string_append(as, &c, 1)) == NULL)
    __archive_errx(1, "Out of memory");
  return (as);
}

struct archive_wstring *
archive_wstrappend_wchar(struct archive_wstring *as, wchar_t c)
{
  if ((as = archive_wstring_append(as, &c, 1)) == NULL)
    __archive_errx(1, "Out of memory");
  return (as);
}

/*
 * Get the "current character set" name to use with iconv.
 * On FreeBSD, the empty character set name "" chooses
 * the correct character encoding for the current locale,
 * so this isn't necessary.
 * But iconv on Mac OS 10.6 doesn't seem to handle this correctly;
 * on that system, we have to explicitly call nl_langinfo()
 * to get the right name.  Not sure about other platforms.
 *
 * NOTE: GNU libiconv does not recognize the character-set name
 * which some platform nl_langinfo(CODESET) returns, so we should
 * use locale_charset() instead of nl_langinfo(CODESET) for GNU libiconv.
 */
static const char *
default_iconv_charset(const char *charset) {
  if (charset != NULL && charset[0] != '\0')
    return charset;
#if HAVE_LOCALE_CHARSET && !defined(__APPLE__)
  /* locale_charset() is broken on Mac OS */
  return locale_charset();
#elif HAVE_NL_LANGINFO
  return nl_langinfo(CODESET);
#else
  return "";
#endif
}

#if defined(_WIN32) && !defined(__CYGWIN__)

/*
 * Convert MBS to WCS.
 * Note: returns -1 if conversion fails.
 */
int
archive_wstring_append_from_mbs(struct archive_wstring *dest,
    const char *p, size_t len)
{
  return archive_wstring_append_from_mbs_in_codepage(dest, p, len, NULL);
}

static int
archive_wstring_append_from_mbs_in_codepage(struct archive_wstring *dest,
    const char *s, size_t length, struct archive_string_conv *sc)
{
  int ret = 0;
  size_t count;
  UINT from_cp;

  if (sc != NULL)
    from_cp = sc->from_cp;
  else
    from_cp = get_current_codepage();

  if (from_cp == CP_C_LOCALE) {
    /*
     * "C" locale special processing.
     */
    wchar_t *ws;
    const unsigned char *mp;

    if (NULL == archive_wstring_ensure(dest,
        dest->length + length + 1))
      return (-1);

    ws = dest->s + dest->length;
    mp = (const unsigned char *)s;
    count = 0;
    while (count < length && *mp) {
      *ws++ = (wchar_t)*mp++;
      count++;
    }
  } else if (sc != NULL &&
      (sc->flag & (SCONV_NORMALIZATION_C | SCONV_NORMALIZATION_D))) {
    /*
     * Normalize UTF-8 and UTF-16BE and convert it directly
     * to UTF-16 as wchar_t.
     */
    struct archive_string u16;
    int saved_flag = sc->flag;/* save current flag. */

    if (IS_BIG_ENDIAN)
      sc->flag |= SCONV_TO_UTF16BE;
    else
      sc->flag |= SCONV_TO_UTF16LE;

    if (sc->flag & SCONV_FROM_UTF16) {
      /*
       *  UTF-16BE/LE NFD ===> UTF-16 NFC
       *  UTF-16BE/LE NFC ===> UTF-16 NFD
       */
      count = utf16nbytes(s, length);
    } else {
      /*
       *  UTF-8 NFD ===> UTF-16 NFC
       *  UTF-8 NFC ===> UTF-16 NFD
       */
      count = mbsnbytes(s, length);
    }
    u16.s = (char *)dest->s;
    u16.length = dest->length << 1;
    u16.buffer_length = dest->buffer_length;
    if (sc->flag & SCONV_NORMALIZATION_C)
      ret = archive_string_normalize_C(&u16, s, count, sc);
    else
      ret = archive_string_normalize_D(&u16, s, count, sc);
    dest->s = (wchar_t *)u16.s;
    dest->length = u16.length >> 1;
    dest->buffer_length = u16.buffer_length;
    sc->flag = saved_flag;/* restore the saved flag. */
    return (ret);
  } else if (sc != NULL && (sc->flag & SCONV_FROM_UTF16)) {
    count = utf16nbytes(s, length);
    count >>= 1; /* to be WCS length */
    /* Allocate memory for WCS. */
    if (NULL == archive_wstring_ensure(dest,
        dest->length + count + 1))
      return (-1);
    wmemcpy(dest->s + dest->length, (const wchar_t *)s, count);
    if ((sc->flag & SCONV_FROM_UTF16BE) && !IS_BIG_ENDIAN) {
      uint16_t *u16 = (uint16_t *)(dest->s + dest->length);
      size_t b;
      for (b = 0; b < count; b++) {
        uint16_t val = archive_le16dec(u16+b);
        archive_be16enc(u16+b, val);
      }
    } else if ((sc->flag & SCONV_FROM_UTF16LE) && IS_BIG_ENDIAN) {
      uint16_t *u16 = (uint16_t *)(dest->s + dest->length);
      size_t b;
      for (b = 0; b < count; b++) {
        uint16_t val = archive_be16dec(u16+b);
        archive_le16enc(u16+b, val);
      }
    }
  } else {
    DWORD mbflag;
    size_t buffsize;

    if (sc == NULL)
      mbflag = 0;
    else if (sc->flag & SCONV_FROM_CHARSET) {
      /* Do not trust the length which comes from
       * an archive file. */
      length = mbsnbytes(s, length);
      mbflag = 0;
    } else
      mbflag = MB_PRECOMPOSED;

    mbflag |= MB_ERR_INVALID_CHARS;

    buffsize = dest->length + length + 1;
    do {
      int r;

      /* MultiByteToWideChar is limited to int. */
      if (length > (size_t)INT_MAX ||
        (dest->buffer_length >> 1) > (size_t)INT_MAX)
        return (-1);
      /* Allocate memory for WCS. */
      if (NULL == archive_wstring_ensure(dest, buffsize))
        return (-1);
      /* Convert MBS to WCS. */
      r = MultiByteToWideChar(from_cp,
          mbflag, s, (int)length, dest->s + dest->length,
          (int)(dest->buffer_length >> 1) -1);
      if (r == 0 &&
          GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
        /* Expand the WCS buffer. */
        buffsize = dest->buffer_length << 1;
        continue;
      }
      if (r == 0 && length != 0)
        ret = -1;
      count = (size_t)r;
      break;
    } while (1);
  }
  dest->length += count;
  dest->s[dest->length] = L'\0';
  return (ret);
}

#else

/*
 * Convert MBS to WCS.
 * Note: returns -1 if conversion fails.
 */
int
archive_wstring_append_from_mbs(struct archive_wstring *dest,
    const char *p, size_t len)
{
  size_t r;
  int ret_val = 0;
  /*
   * No single byte will be more than one wide character,
   * so this length estimate will always be big enough.
   */
  // size_t wcs_length = len;
  size_t mbs_length = len;
  const char *mbs = p;
  wchar_t *wcs;
#if HAVE_MBRTOWC
  mbstate_t shift_state;

  memset(&shift_state, 0, sizeof(shift_state));
#endif
  /*
   * As we decided to have wcs_length == mbs_length == len
   * we can use len here instead of wcs_length
   */
  if (NULL == archive_wstring_ensure(dest, dest->length + len + 1))
    return (-1);
  wcs = dest->s + dest->length;
  /*
   * We cannot use mbsrtowcs/mbstowcs here because those may convert
   * extra MBS when strlen(p) > len and one wide character consists of
   * multi bytes.
   */
  while (*mbs && mbs_length > 0) {
    /*
     * The buffer we allocated is always big enough.
     * Keep this code path in a comment if we decide to choose
     * smaller wcs_length in the future
     */
/*
    if (wcs_length == 0) {
      dest->length = wcs - dest->s;
      dest->s[dest->length] = L'\0';
      wcs_length = mbs_length;
      if (NULL == archive_wstring_ensure(dest,
          dest->length + wcs_length + 1))
        return (-1);
      wcs = dest->s + dest->length;
    }
*/
#if HAVE_MBRTOWC
    r = mbrtowc(wcs, mbs, mbs_length, &shift_state);
#else
    r = mbtowc(wcs, mbs, mbs_length);
#endif
    if (r == (size_t)-1 || r == (size_t)-2) {
      ret_val = -1;
      break;
    }
    if (r == 0 || r > mbs_length)
      break;
    wcs++;
    // wcs_length--;
    mbs += r;
    mbs_length -= r;
  }
  dest->length = wcs - dest->s;
  dest->s[dest->length] = L'\0';
  return (ret_val);
}

#endif

#if defined(_WIN32) && !defined(__CYGWIN__)

/*
 * WCS ==> MBS.
 * Note: returns -1 if conversion fails.
 *
 * Win32 builds use WideCharToMultiByte from the Windows API.
 * (Maybe Cygwin should too?  WideCharToMultiByte will know a
 * lot more about local character encodings than the wcrtomb()
 * wrapper is going to know.)
 */
int
archive_string_append_from_wcs(struct archive_string *as,
    const wchar_t *w, size_t len)
{
  return archive_string_append_from_wcs_in_codepage(as, w, len, NULL);
}

static int
archive_string_append_from_wcs_in_codepage(struct archive_string *as,
    const wchar_t *ws, size_t len, struct archive_string_conv *sc)
{
  BOOL defchar_used, *dp;
  int ret = 0;
  UINT to_cp;
  size_t count, wslen = len;

  if (sc != NULL)
    to_cp = sc->to_cp;
  else
    to_cp = get_current_codepage();

  if (to_cp == CP_C_LOCALE) {
    /*
     * "C" locale special processing.
     */
    const wchar_t *wp = ws;
    char *p;

    if (NULL == archive_string_ensure(as,
        as->length + wslen +1))
      return (-1);
    p = as->s + as->length;
    count = 0;
    defchar_used = 0;
    while (count < wslen && *wp) {
      if (*wp > 255) {
        *p++ = '?';
        wp++;
        defchar_used = 1;
      } else
        *p++ = (char)*wp++;
      count++;
    }
  } else if (sc != NULL && (sc->flag & SCONV_TO_UTF16)) {
    uint16_t *u16;

    if (NULL ==
        archive_string_ensure(as, as->length + len * 2 + 2))
      return (-1);
    u16 = (uint16_t *)(as->s + as->length);
    count = 0;
    defchar_used = 0;
    if (sc->flag & SCONV_TO_UTF16BE) {
      while (count < len && *ws) {
        archive_be16enc(u16+count, *ws);
        ws++;
        count++;
      }
    } else {
      while (count < len && *ws) {
        archive_le16enc(u16+count, *ws);
        ws++;
        count++;
      }
    }
    count <<= 1; /* to be byte size */
  } else {
    /* Make sure the MBS buffer has plenty to set. */
    if (NULL ==
        archive_string_ensure(as, as->length + len * 2 + 1))
      return (-1);
    do {
      int r;

      defchar_used = 0;
      if (to_cp == CP_UTF8)
        dp = NULL;
      else
        dp = &defchar_used;
      /* WideCharToMultiByte is limited to int. */
      if (as->buffer_length - as->length - 1 > (size_t)INT_MAX ||
        wslen > (size_t)INT_MAX)
        return (-1);
      r = WideCharToMultiByte(to_cp, 0, ws, (int)wslen,
          as->s + as->length,
          (int)(as->buffer_length - as->length - 1), NULL, dp);
      if (r == 0 &&
          GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
        /* Expand the MBS buffer and retry. */
        if (NULL == archive_string_ensure(as,
          as->buffer_length + len))
          return (-1);
        continue;
      }
      if (r == 0)
        ret = -1;
      count = (size_t)r;
      break;
    } while (1);
  }
  as->length += count;
  as->s[as->length] = '\0';
  return (defchar_used?-1:ret);
}

#elif defined(HAVE_WCTOMB) || defined(HAVE_WCRTOMB)

/*
 * Translates a wide character string into current locale character set
 * and appends to the archive_string.  Note: returns -1 if conversion
 * fails.
 */
int
archive_string_append_from_wcs(struct archive_string *as,
    const wchar_t *w, size_t len)
{
  /* We cannot use the standard wcstombs() here because it
   * cannot tell us how big the output buffer should be.  So
   * I've built a loop around wcrtomb() or wctomb() that
   * converts a character at a time and resizes the string as
   * needed.  We prefer wcrtomb() when it's available because
   * it's thread-safe. */
  int n, ret_val = 0;
  char *p;
  char *end;
#if HAVE_WCRTOMB
  mbstate_t shift_state;

  memset(&shift_state, 0, sizeof(shift_state));
#else
  /* Clear the shift state before starting. */
  wctomb(NULL, L'\0');
#endif
  /*
   * Allocate buffer for MBS.
   * We need this allocation here since it is possible that
   * as->s is still NULL.
   */
  if (archive_string_ensure(as, as->length + len + 1) == NULL)
    return (-1);

  p = as->s + as->length;
  end = as->s + as->buffer_length - MB_CUR_MAX -1;
  while (*w != L'\0' && len > 0) {
    if (p >= end) {
      as->length = p - as->s;
      as->s[as->length] = '\0';
      /* Re-allocate buffer for MBS. */
      if (archive_string_ensure(as,
          as->length + max(len * 2,
          (size_t)MB_CUR_MAX) + 1) == NULL)
        return (-1);
      p = as->s + as->length;
      end = as->s + as->buffer_length - MB_CUR_MAX -1;
    }
#if HAVE_WCRTOMB
    n = wcrtomb(p, *w++, &shift_state);
#else
    n = wctomb(p, *w++);
#endif
    if (n == -1) {
      if (errno == EILSEQ) {
        /* Skip an illegal wide char. */
        *p++ = '?';
        ret_val = -1;
      } else {
        ret_val = -1;
        break;
      }
    } else
      p += n;
    len--;
  }
  as->length = p - as->s;
  as->s[as->length] = '\0';
  return (ret_val);
}

#else /* HAVE_WCTOMB || HAVE_WCRTOMB */

/*
 * TODO: Test if __STDC_ISO_10646__ is defined.
 * Non-Windows uses ISO C wcrtomb() or wctomb() to perform the conversion
 * one character at a time.  If a non-Windows platform doesn't have
 * either of these, fall back to the built-in UTF8 conversion.
 */
int
archive_string_append_from_wcs(struct archive_string *as,
    const wchar_t *w, size_t len)
{
  (void)as;/* UNUSED */
  (void)w;/* UNUSED */
  (void)len;/* UNUSED */
  errno = ENOSYS;
  return (-1);
}

#endif /* HAVE_WCTOMB || HAVE_WCRTOMB */

/*
 * Find a string conversion object by a pair of 'from' charset name
 * and 'to' charset name from an archive object.
 * Return NULL if not found.
 */
static struct archive_string_conv *
find_sconv_object(struct archive *a, const char *fc, const char *tc)
{
  struct archive_string_conv *sc; 

  if (a == NULL)
    return (NULL);

  for (sc = a->sconv; sc != NULL; sc = sc->next) {
    if (strcmp(sc->from_charset, fc) == 0 &&
        strcmp(sc->to_charset, tc) == 0)
      break;
  }
  return (sc);
}

/*
 * Register a string object to an archive object.
 */
static void
add_sconv_object(struct archive *a, struct archive_string_conv *sc)
{
  struct archive_string_conv **psc; 

  /* Add a new sconv to sconv list. */
  psc = &(a->sconv);
  while (*psc != NULL)
    psc = &((*psc)->next);
  *psc = sc;
}

static void
add_converter(struct archive_string_conv *sc, int (*converter)
    (struct archive_string *, const void *, size_t,
     struct archive_string_conv *))
{
  if (sc == NULL || sc->nconverter >= 2)
    __archive_errx(1, "Programming error");
  sc->converter[sc->nconverter++] = converter;
}

static void
setup_converter(struct archive_string_conv *sc)
{

  /* Reset. */
  sc->nconverter = 0;

  /*
   * Perform special sequence for the incorrect UTF-8 filenames
   * made by libarchive2.x.
   */
  if (sc->flag & SCONV_UTF8_LIBARCHIVE_2) {
    add_converter(sc, strncat_from_utf8_libarchive2);
    return;
  }

  /*
   * Convert a string to UTF-16BE/LE.
   */
  if (sc->flag & SCONV_TO_UTF16) {
    /*
     * If the current locale is UTF-8, we can translate
     * a UTF-8 string into a UTF-16BE string.
     */
    if (sc->flag & SCONV_FROM_UTF8) {
      add_converter(sc, archive_string_append_unicode);
      return;
    }

#if defined(_WIN32) && !defined(__CYGWIN__)
    if (sc->flag & SCONV_WIN_CP) {
      if (sc->flag & SCONV_TO_UTF16BE)
        add_converter(sc, win_strncat_to_utf16be);
      else
        add_converter(sc, win_strncat_to_utf16le);
      return;
    }
#endif

#if defined(HAVE_ICONV)
    if (sc->cd != (iconv_t)-1) {
      add_converter(sc, iconv_strncat_in_locale);
      return;
    }
#endif

    if (sc->flag & SCONV_BEST_EFFORT) {
      if (sc->flag & SCONV_TO_UTF16BE)
        add_converter(sc,
          best_effort_strncat_to_utf16be);
      else
        add_converter(sc,
          best_effort_strncat_to_utf16le);
    } else
      /* Make sure we have no converter. */
      sc->nconverter = 0;
    return;
  }

  /*
   * Convert a string from UTF-16BE/LE.
   */
  if (sc->flag & SCONV_FROM_UTF16) {
    /*
     * At least we should normalize a UTF-16BE string.
     */
    if (sc->flag & SCONV_NORMALIZATION_D)
      add_converter(sc,archive_string_normalize_D);
    else if (sc->flag & SCONV_NORMALIZATION_C)
      add_converter(sc, archive_string_normalize_C);

    if (sc->flag & SCONV_TO_UTF8) {
      /*
       * If the current locale is UTF-8, we can translate
       * a UTF-16BE/LE string into a UTF-8 string directly.
       */
      if (!(sc->flag &
          (SCONV_NORMALIZATION_D |SCONV_NORMALIZATION_C)))
        add_converter(sc,
            archive_string_append_unicode);
      return;
    }

#if defined(_WIN32) && !defined(__CYGWIN__)
    if (sc->flag & SCONV_WIN_CP) {
      if (sc->flag & SCONV_FROM_UTF16BE)
        add_converter(sc, win_strncat_from_utf16be);
      else
        add_converter(sc, win_strncat_from_utf16le);
      return;
    }
#endif

#if defined(HAVE_ICONV)
    if (sc->cd != (iconv_t)-1) {
      add_converter(sc, iconv_strncat_in_locale);
      return;
    }
#endif

    if ((sc->flag & (SCONV_BEST_EFFORT | SCONV_FROM_UTF16BE))
        == (SCONV_BEST_EFFORT | SCONV_FROM_UTF16BE))
      add_converter(sc, best_effort_strncat_from_utf16be);
    else if ((sc->flag & (SCONV_BEST_EFFORT | SCONV_FROM_UTF16LE))
        == (SCONV_BEST_EFFORT | SCONV_FROM_UTF16LE))
      add_converter(sc, best_effort_strncat_from_utf16le);
    else
      /* Make sure we have no converter. */
      sc->nconverter = 0;
    return;
  }

  if (sc->flag & SCONV_FROM_UTF8) {
    /*
     * At least we should normalize a UTF-8 string.
     */
    if (sc->flag & SCONV_NORMALIZATION_D)
      add_converter(sc,archive_string_normalize_D);
    else if (sc->flag & SCONV_NORMALIZATION_C)
      add_converter(sc, archive_string_normalize_C);

    /*
     * Copy UTF-8 string with a check of CESU-8.
     * Apparently, iconv does not check surrogate pairs in UTF-8
     * when both from-charset and to-charset are UTF-8, and then
     * we use our UTF-8 copy code.
     */
    if (sc->flag & SCONV_TO_UTF8) {
      /*
       * If the current locale is UTF-8, we can translate
       * a UTF-16BE string into a UTF-8 string directly.
       */
      if (!(sc->flag &
          (SCONV_NORMALIZATION_D |SCONV_NORMALIZATION_C)))
        add_converter(sc, strncat_from_utf8_to_utf8);
      return;
    }
  }

#if defined(_WIN32) && !defined(__CYGWIN__)
  /*
   * On Windows we can use Windows API for a string conversion.
   */
  if (sc->flag & SCONV_WIN_CP) {
    add_converter(sc, strncat_in_codepage);
    return;
  }
#endif

#if HAVE_ICONV
  if (sc->cd != (iconv_t)-1) {
    add_converter(sc, iconv_strncat_in_locale);
    /*
     * iconv generally does not support UTF-8-MAC and so
     * we have to the output of iconv from NFC to NFD if
     * need.
     */
    if ((sc->flag & SCONV_FROM_CHARSET) &&
        (sc->flag & SCONV_TO_UTF8)) {
      if (sc->flag & SCONV_NORMALIZATION_D)
        add_converter(sc, archive_string_normalize_D);
    }
    return;
  }
#endif

  /*
   * Try conversion in the best effort or no conversion.
   */
  if ((sc->flag & SCONV_BEST_EFFORT) || sc->same)
    add_converter(sc, best_effort_strncat_in_locale);
  else
    /* Make sure we have no converter. */
    sc->nconverter = 0;
}

/*
 * Return canonicalized charset-name but this supports just UTF-8, UTF-16BE
 * and CP932 which are referenced in create_sconv_object().
 */
static const char *
canonical_charset_name(const char *charset)
{
  char cs[16];
  char *p;
  const char *s;

  if (charset == NULL || charset[0] == '\0'
      || strlen(charset) > 15)
    return (charset);

  /* Copy name to uppercase. */
  p = cs;
  s = charset;
  while (*s) {
    char c = *s++;
    if (c >= 'a' && c <= 'z')
      c -= 'a' - 'A';
    *p++ = c;
  }
  *p++ = '\0';

  if (strcmp(cs, "UTF-8") == 0 ||
      strcmp(cs, "UTF8") == 0)
    return ("UTF-8");
  if (strcmp(cs, "UTF-16BE") == 0 ||
      strcmp(cs, "UTF16BE") == 0)
    return ("UTF-16BE");
  if (strcmp(cs, "UTF-16LE") == 0 ||
      strcmp(cs, "UTF16LE") == 0)
    return ("UTF-16LE");
  if (strcmp(cs, "CP932") == 0)
    return ("CP932");
  return (charset);
}

/*
 * Create a string conversion object.
 */
static struct archive_string_conv *
create_sconv_object(const char *fc, const char *tc,
    unsigned current_codepage, int flag)
{
  struct archive_string_conv *sc; 

  sc = calloc(1, sizeof(*sc));
  if (sc == NULL)
    return (NULL);
  sc->next = NULL;
  sc->from_charset = strdup(fc);
  if (sc->from_charset == NULL) {
    free(sc);
    return (NULL);
  }
  sc->to_charset = strdup(tc);
  if (sc->to_charset == NULL) {
    free(sc->from_charset);
    free(sc);
    return (NULL);
  }
  archive_string_init(&sc->utftmp);

  if (flag & SCONV_TO_CHARSET) {
    /*
     * Convert characters from the current locale charset to
     * a specified charset.
     */
    sc->from_cp = current_codepage;
    sc->to_cp = make_codepage_from_charset(tc);
#if defined(_WIN32) && !defined(__CYGWIN__)
    if (IsValidCodePage(sc->to_cp))
      flag |= SCONV_WIN_CP;
#endif
  } else if (flag & SCONV_FROM_CHARSET) {
    /*
     * Convert characters from a specified charset to
     * the current locale charset.
     */
    sc->to_cp = current_codepage;
    sc->from_cp = make_codepage_from_charset(fc);
#if defined(_WIN32) && !defined(__CYGWIN__)
    if (IsValidCodePage(sc->from_cp))
      flag |= SCONV_WIN_CP;
#endif
  }

  /*
   * Check if "from charset" and "to charset" are the same.
   */
  if (strcmp(fc, tc) == 0 ||
      (sc->from_cp != (unsigned)-1 && sc->from_cp == sc->to_cp))
    sc->same = 1;
  else
    sc->same = 0;

  /*
   * Mark if "from charset" or "to charset" are UTF-8 or UTF-16BE/LE.
   */
  if (strcmp(tc, "UTF-8") == 0)
    flag |= SCONV_TO_UTF8;
  else if (strcmp(tc, "UTF-16BE") == 0)
    flag |= SCONV_TO_UTF16BE;
  else if (strcmp(tc, "UTF-16LE") == 0)
    flag |= SCONV_TO_UTF16LE;
  if (strcmp(fc, "UTF-8") == 0)
    flag |= SCONV_FROM_UTF8;
  else if (strcmp(fc, "UTF-16BE") == 0)
    flag |= SCONV_FROM_UTF16BE;
  else if (strcmp(fc, "UTF-16LE") == 0)
    flag |= SCONV_FROM_UTF16LE;
#if defined(_WIN32) && !defined(__CYGWIN__)
  if (sc->to_cp == CP_UTF8)
    flag |= SCONV_TO_UTF8;
  else if (sc->to_cp == CP_UTF16BE)
    flag |= SCONV_TO_UTF16BE | SCONV_WIN_CP;
  else if (sc->to_cp == CP_UTF16LE)
    flag |= SCONV_TO_UTF16LE | SCONV_WIN_CP;
  if (sc->from_cp == CP_UTF8)
    flag |= SCONV_FROM_UTF8;
  else if (sc->from_cp == CP_UTF16BE)
    flag |= SCONV_FROM_UTF16BE | SCONV_WIN_CP;
  else if (sc->from_cp == CP_UTF16LE)
    flag |= SCONV_FROM_UTF16LE | SCONV_WIN_CP;
#endif

  /*
   * Set a flag for Unicode NFD. Usually iconv cannot correctly
   * handle it. So we have to translate NFD characters to NFC ones
   * ourselves before iconv handles. Another reason is to prevent
   * that the same sight of two filenames, one is NFC and other
   * is NFD, would be in its directory.
   * On Mac OS X, although its filesystem layer automatically
   * convert filenames to NFD, it would be useful for filename
   * comparing to find out the same filenames that we normalize
   * that to be NFD ourselves.
   */
  if ((flag & SCONV_FROM_CHARSET) &&
      (flag & (SCONV_FROM_UTF16 | SCONV_FROM_UTF8))) {
#if defined(__APPLE__)
    if (flag & SCONV_TO_UTF8)
      flag |= SCONV_NORMALIZATION_D;
    else
#endif
      flag |= SCONV_NORMALIZATION_C;
  }
#if defined(__APPLE__)
  /*
   * In case writing an archive file, make sure that a filename
   * going to be passed to iconv is a Unicode NFC string since
   * a filename in HFS Plus filesystem is a Unicode NFD one and
   * iconv cannot handle it with "UTF-8" charset. It is simpler
   * than a use of "UTF-8-MAC" charset.
   */
  if ((flag & SCONV_TO_CHARSET) &&
      (flag & (SCONV_FROM_UTF16 | SCONV_FROM_UTF8)) &&
      !(flag & (SCONV_TO_UTF16 | SCONV_TO_UTF8)))
    flag |= SCONV_NORMALIZATION_C;
  /*
   * In case reading an archive file. make sure that a filename
   * will be passed to users is a Unicode NFD string in order to
   * correctly compare the filename with other one which comes
   * from HFS Plus filesystem.
   */
  if ((flag & SCONV_FROM_CHARSET) &&
     !(flag & (SCONV_FROM_UTF16 | SCONV_FROM_UTF8)) &&
      (flag & SCONV_TO_UTF8))
    flag |= SCONV_NORMALIZATION_D;
#endif

#if defined(HAVE_ICONV)
  sc->cd_w = (iconv_t)-1;
  /*
   * Create an iconv object.
   */
  if (((flag & (SCONV_TO_UTF8 | SCONV_TO_UTF16)) &&
      (flag & (SCONV_FROM_UTF8 | SCONV_FROM_UTF16))) ||
      (flag & SCONV_WIN_CP)) {
    /* This case we won't use iconv. */
    sc->cd = (iconv_t)-1;
  } else {
    sc->cd = iconv_open(tc, fc);
    if (sc->cd == (iconv_t)-1 && (sc->flag & SCONV_BEST_EFFORT)) {
      /*
       * Unfortunately, all of iconv implements do support
       * "CP932" character-set, so we should use "SJIS"
       * instead if iconv_open failed.
       */
      if (strcmp(tc, "CP932") == 0)
        sc->cd = iconv_open("SJIS", fc);
      else if (strcmp(fc, "CP932") == 0)
        sc->cd = iconv_open(tc, "SJIS");
    }
#if defined(_WIN32) && !defined(__CYGWIN__)
    /*
     * archive_mstring on Windows directly convert multi-bytes
     * into archive_wstring in order not to depend on locale
     * so that you can do a I18N programming. This will be
     * used only in archive_mstring_copy_mbs_len_l so far.
     */
    if (flag & SCONV_FROM_CHARSET) {
      sc->cd_w = iconv_open("UTF-8", fc);
      if (sc->cd_w == (iconv_t)-1 &&
          (sc->flag & SCONV_BEST_EFFORT)) {
        if (strcmp(fc, "CP932") == 0)
          sc->cd_w = iconv_open("UTF-8", "SJIS");
      }
    }
#endif /* _WIN32 && !__CYGWIN__ */
  }
#endif  /* HAVE_ICONV */

  sc->flag = flag;

  /*
   * Set up converters.
   */
  setup_converter(sc);

  return (sc);
}

/*
 * Free a string conversion object.
 */
static void
free_sconv_object(struct archive_string_conv *sc)
{
  free(sc->from_charset);
  free(sc->to_charset);
  archive_string_free(&sc->utftmp);
#if HAVE_ICONV
  if (sc->cd != (iconv_t)-1)
    iconv_close(sc->cd);
  if (sc->cd_w != (iconv_t)-1)
    iconv_close(sc->cd_w);
#endif
  free(sc);
}

#if defined(_WIN32) && !defined(__CYGWIN__)
# if defined(WINAPI_FAMILY_PARTITION) && !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
#  define GetOEMCP() CP_OEMCP
# endif

static unsigned
my_atoi(const char *p)
{
  unsigned cp;

  cp = 0;
  while (*p) {
    if (*p >= '0' && *p <= '9')
      cp = cp * 10 + (*p - '0');
    else
      return (-1);
    p++;
  }
  return (cp);
}

/*
 * Translate Charset name (as used by iconv) into CodePage (as used by Windows)
 * Return -1 if failed.
 *
 * Note: This translation code may be insufficient.
 */
static struct charset {
  const char *name;
  unsigned cp;
} charsets[] = {
  /* MUST BE SORTED! */
  {"ASCII", 1252},
  {"ASMO-708", 708},
  {"BIG5", 950},
  {"CHINESE", 936},
  {"CP367", 1252},
  {"CP819", 1252},
  {"CP1025", 21025},
  {"DOS-720", 720},
  {"DOS-862", 862},
  {"EUC-CN", 51936},
  {"EUC-JP", 51932},
  {"EUC-KR", 949},
  {"EUCCN", 51936},
  {"EUCJP", 51932},
  {"EUCKR", 949},
  {"GB18030", 54936},
  {"GB2312", 936},
  {"HEBREW", 1255},
  {"HZ-GB-2312", 52936},
  {"IBM273", 20273},
  {"IBM277", 20277},
  {"IBM278", 20278},
  {"IBM280", 20280},
  {"IBM284", 20284},
  {"IBM285", 20285},
  {"IBM290", 20290},
  {"IBM297", 20297},
  {"IBM367", 1252},
  {"IBM420", 20420},
  {"IBM423", 20423},
  {"IBM424", 20424},
  {"IBM819", 1252},
  {"IBM871", 20871},
  {"IBM880", 20880},
  {"IBM905", 20905},
  {"IBM924", 20924},
  {"ISO-8859-1", 28591},
  {"ISO-8859-13", 28603},
  {"ISO-8859-15", 28605},
  {"ISO-8859-2", 28592},
  {"ISO-8859-3", 28593},
  {"ISO-8859-4", 28594},
  {"ISO-8859-5", 28595},
  {"ISO-8859-6", 28596},
  {"ISO-8859-7", 28597},
  {"ISO-8859-8", 28598},
  {"ISO-8859-9", 28599},
  {"ISO8859-1", 28591},
  {"ISO8859-13", 28603},
  {"ISO8859-15", 28605},
  {"ISO8859-2", 28592},
  {"ISO8859-3", 28593},
  {"ISO8859-4", 28594},
  {"ISO8859-5", 28595},
  {"ISO8859-6", 28596},
  {"ISO8859-7", 28597},
  {"ISO8859-8", 28598},
  {"ISO8859-9", 28599},
  {"JOHAB", 1361},
  {"KOI8-R", 20866},
  {"KOI8-U", 21866},
  {"KS_C_5601-1987", 949},
  {"LATIN1", 1252},
  {"LATIN2", 28592},
  {"MACINTOSH", 10000},
  {"SHIFT-JIS", 932},
  {"SHIFT_JIS", 932},
  {"SJIS", 932},
  {"US", 1252},
  {"US-ASCII", 1252},
  {"UTF-16", 1200},
  {"UTF-16BE", 1201},
  {"UTF-16LE", 1200},
  {"UTF-8", CP_UTF8},
  {"X-EUROPA", 29001},
  {"X-MAC-ARABIC", 10004},
  {"X-MAC-CE", 10029},
  {"X-MAC-CHINESEIMP", 10008},
  {"X-MAC-CHINESETRAD", 10002},
  {"X-MAC-CROATIAN", 10082},
  {"X-MAC-CYRILLIC", 10007},
  {"X-MAC-GREEK", 10006},
  {"X-MAC-HEBREW", 10005},
  {"X-MAC-ICELANDIC", 10079},
  {"X-MAC-JAPANESE", 10001},
  {"X-MAC-KOREAN", 10003},
  {"X-MAC-ROMANIAN", 10010},
  {"X-MAC-THAI", 10021},
  {"X-MAC-TURKISH", 10081},
  {"X-MAC-UKRAINIAN", 10017},
};
static unsigned
make_codepage_from_charset(const char *charset)
{
  char cs[16];
  char *p;
  unsigned cp;
  int a, b;

  if (charset == NULL || strlen(charset) > 15)
    return -1;

  /* Copy name to uppercase. */
  p = cs;
  while (*charset) {
    char c = *charset++;
    if (c >= 'a' && c <= 'z')
      c -= 'a' - 'A';
    *p++ = c;
  }
  *p++ = '\0';
  cp = -1;

  /* Look it up in the table first, so that we can easily
   * override CP367, which we map to 1252 instead of 367. */
  a = 0;
  b = sizeof(charsets)/sizeof(charsets[0]);
  while (b > a) {
    int c = (b + a) / 2;
    int r = strcmp(charsets[c].name, cs);
    if (r < 0)
      a = c + 1;
    else if (r > 0)
      b = c;
    else
      return charsets[c].cp;
  }

  /* If it's not in the table, try to parse it. */
  switch (*cs) {
  case 'C':
    if (cs[1] == 'P' && cs[2] >= '0' && cs[2] <= '9') {
      cp = my_atoi(cs + 2);
    } else if (strcmp(cs, "CP_ACP") == 0)
      cp = get_current_codepage();
    else if (strcmp(cs, "CP_OEMCP") == 0)
      cp = get_current_oemcp();
    break;
  case 'I':
    if (cs[1] == 'B' && cs[2] == 'M' &&
        cs[3] >= '0' && cs[3] <= '9') {
      cp = my_atoi(cs + 3);
    }
    break;
  case 'W':
    if (strncmp(cs, "WINDOWS-", 8) == 0) {
      cp = my_atoi(cs + 8);
      if (cp != 874 && (cp < 1250 || cp > 1258))
        cp = -1;/* This may invalid code. */
    }
    break;
  }
  return (cp);
}

/*
 * Return ANSI Code Page of current locale set by setlocale().
 */
static unsigned
get_current_codepage(void)
{
  char *locale, *p;
  unsigned cp;

  locale = setlocale(LC_CTYPE, NULL);
  if (locale == NULL)
    return (GetACP());
  if (locale[0] == 'C' && locale[1] == '\0')
    return (CP_C_LOCALE);
  p = strrchr(locale, '.');
  if (p == NULL)
    return (GetACP());
  if ((strcmp(p+1, "utf8") == 0) || (strcmp(p+1, "UTF-8") == 0))
    return CP_UTF8;
  cp = my_atoi(p+1);
  if ((int)cp <= 0)
    return (GetACP());
  return (cp);
}

/*
 * Translation table between Locale Name and ACP/OEMCP.
 */
static struct {
  unsigned acp;
  unsigned ocp;
  const char *locale;
} acp_ocp_map[] = {
  {  950,  950, "Chinese_Taiwan" },
  {  936,  936, "Chinese_People's Republic of China" },
  {  950,  950, "Chinese_Taiwan" },
  { 1250,  852, "Czech_Czech Republic" },
  { 1252,  850, "Danish_Denmark" },
  { 1252,  850, "Dutch_Netherlands" },
  { 1252,  850, "Dutch_Belgium" },
  { 1252,  437, "English_United States" },
  { 1252,  850, "English_Australia" },
  { 1252,  850, "English_Canada" },
  { 1252,  850, "English_New Zealand" },
  { 1252,  850, "English_United Kingdom" },
  { 1252,  437, "English_United States" },
  { 1252,  850, "Finnish_Finland" },
  { 1252,  850, "French_France" },
  { 1252,  850, "French_Belgium" },
  { 1252,  850, "French_Canada" },
  { 1252,  850, "French_Switzerland" },
  { 1252,  850, "German_Germany" },
  { 1252,  850, "German_Austria" },
  { 1252,  850, "German_Switzerland" },
  { 1253,  737, "Greek_Greece" },
  { 1250,  852, "Hungarian_Hungary" },
  { 1252,  850, "Icelandic_Iceland" },
  { 1252,  850, "Italian_Italy" },
  { 1252,  850, "Italian_Switzerland" },
  {  932,  932, "Japanese_Japan" },
  {  949,  949, "Korean_Korea" },
  { 1252,  850, "Norwegian (BokmOl)_Norway" },
  { 1252,  850, "Norwegian (BokmOl)_Norway" },
  { 1252,  850, "Norwegian-Nynorsk_Norway" },
  { 1250,  852, "Polish_Poland" },
  { 1252,  850, "Portuguese_Portugal" },
  { 1252,  850, "Portuguese_Brazil" },
  { 1251,  866, "Russian_Russia" },
  { 1250,  852, "Slovak_Slovakia" },
  { 1252,  850, "Spanish_Spain" },
  { 1252,  850, "Spanish_Mexico" },
  { 1252,  850, "Spanish_Spain" },
  { 1252,  850, "Swedish_Sweden" },
  { 1254,  857, "Turkish_Turkey" },
  { 0, 0, NULL}
};

/*
 * Return OEM Code Page of current locale set by setlocale().
 */
static unsigned
get_current_oemcp(void)
{
  int i;
  char *locale, *p;
  size_t len;

  locale = setlocale(LC_CTYPE, NULL);
  if (locale == NULL)
    return (GetOEMCP());
  if (locale[0] == 'C' && locale[1] == '\0')
    return (CP_C_LOCALE);

  p = strrchr(locale, '.');
  if (p == NULL)
    return (GetOEMCP());
  len = p - locale;
  for (i = 0; acp_ocp_map[i].acp; i++) {
    if (strncmp(acp_ocp_map[i].locale, locale, len) == 0)
      return (acp_ocp_map[i].ocp);
  }
  return (GetOEMCP());
}
#else

/*
 * POSIX platform does not use CodePage.
 */

static unsigned
get_current_codepage(void)
{
  return (-1);/* Unknown */
}
static unsigned
make_codepage_from_charset(const char *charset)
{
  (void)charset; /* UNUSED */
  return (-1);/* Unknown */
}
static unsigned
get_current_oemcp(void)
{
  return (-1);/* Unknown */
}

#endif /* defined(_WIN32) && !defined(__CYGWIN__) */

/*
 * Return a string conversion object.
 */
static struct archive_string_conv *
get_sconv_object(struct archive *a, const char *fc, const char *tc, int flag)
{
  struct archive_string_conv *sc;
  unsigned current_codepage;

  /* Check if we have made the sconv object. */
  sc = find_sconv_object(a, fc, tc);
  if (sc != NULL)
    return (sc);

  if (a == NULL)
    current_codepage = get_current_codepage();
  else
    current_codepage = a->current_codepage;

  sc = create_sconv_object(canonical_charset_name(fc),
      canonical_charset_name(tc), current_codepage, flag);
  if (sc == NULL) {
    if (a != NULL)
      archive_set_error(a, ENOMEM,
          "Could not allocate memory for "
          "a string conversion object");
    return (NULL);
  }

  /*
   * If there is no converter for current string conversion object,
   * we cannot handle this conversion.
   */
  if (sc->nconverter == 0) {
    if (a != NULL) {
#if HAVE_ICONV
      archive_set_error(a, ARCHIVE_ERRNO_MISC,
          "iconv_open failed : Cannot handle ``%s''",
          (flag & SCONV_TO_CHARSET)?tc:fc);
#else
      archive_set_error(a, ARCHIVE_ERRNO_MISC,
          "A character-set conversion not fully supported "
          "on this platform");
#endif
    }
    /* Failed; free a sconv object. */
    free_sconv_object(sc);
    return (NULL);
  }

  /*
   * Success!
   */
  if (a != NULL)
    add_sconv_object(a, sc);
  return (sc);
}

static const char *
get_current_charset(struct archive *a)
{
  const char *cur_charset;

  if (a == NULL)
    cur_charset = default_iconv_charset("");
  else {
    cur_charset = default_iconv_charset(a->current_code);
    if (a->current_code == NULL) {
      a->current_code = strdup(cur_charset);
      a->current_codepage = get_current_codepage();
      a->current_oemcp = get_current_oemcp();
    }
  }
  return (cur_charset);
}

/*
 * Make and Return a string conversion object.
 * Return NULL if the platform does not support the specified conversion
 * and best_effort is 0.
 * If best_effort is set, A string conversion object must be returned
 * unless memory allocation for the object fails, but the conversion
 * might fail when non-ASCII code is found.
 */
struct archive_string_conv *
archive_string_conversion_to_charset(struct archive *a, const char *charset,
    int best_effort)
{
  int flag = SCONV_TO_CHARSET;

  if (best_effort)
    flag |= SCONV_BEST_EFFORT;
  return (get_sconv_object(a, get_current_charset(a), charset, flag));
}

struct archive_string_conv *
archive_string_conversion_from_charset(struct archive *a, const char *charset,
    int best_effort)
{
  int flag = SCONV_FROM_CHARSET;

  if (best_effort)
    flag |= SCONV_BEST_EFFORT;
  return (get_sconv_object(a, charset, get_current_charset(a), flag));
}

/*
 * archive_string_default_conversion_*_archive() are provided for Windows
 * platform because other archiver application use CP_OEMCP for
 * MultiByteToWideChar() and WideCharToMultiByte() for the filenames
 * in tar or zip files. But mbstowcs/wcstombs(CRT) usually use CP_ACP
 * unless you use setlocale(LC_ALL, ".OCP")(specify CP_OEMCP).
 * So we should make a string conversion between CP_ACP and CP_OEMCP
 * for compatibility.
 */
#if defined(_WIN32) && !defined(__CYGWIN__)
struct archive_string_conv *
archive_string_default_conversion_for_read(struct archive *a)
{
  const char *cur_charset = get_current_charset(a);
  char oemcp[16];

  /* NOTE: a check of cur_charset is unneeded but we need
   * that get_current_charset() has been surely called at
   * this time whatever C compiler optimized. */
  if (cur_charset != NULL &&
      (a->current_codepage == CP_C_LOCALE ||
       a->current_codepage == a->current_oemcp))
    return (NULL);/* no conversion. */

  _snprintf(oemcp, sizeof(oemcp)-1, "CP%d", a->current_oemcp);
  /* Make sure a null termination must be set. */
  oemcp[sizeof(oemcp)-1] = '\0';
  return (get_sconv_object(a, oemcp, cur_charset,
      SCONV_FROM_CHARSET));
}

struct archive_string_conv *
archive_string_default_conversion_for_write(struct archive *a)
{
  const char *cur_charset = get_current_charset(a);
  char oemcp[16];

  /* NOTE: a check of cur_charset is unneeded but we need
   * that get_current_charset() has been surely called at
   * this time whatever C compiler optimized. */
  if (cur_charset != NULL &&
      (a->current_codepage == CP_C_LOCALE ||
       a->current_codepage == a->current_oemcp))
    return (NULL);/* no conversion. */

  _snprintf(oemcp, sizeof(oemcp)-1, "CP%d", a->current_oemcp);
  /* Make sure a null termination must be set. */
  oemcp[sizeof(oemcp)-1] = '\0';
  return (get_sconv_object(a, cur_charset, oemcp,
      SCONV_TO_CHARSET));
}
#else
struct archive_string_conv *
archive_string_default_conversion_for_read(struct archive *a)
{
  (void)a; /* UNUSED */
  return (NULL);
}

struct archive_string_conv *
archive_string_default_conversion_for_write(struct archive *a)
{
  (void)a; /* UNUSED */
  return (NULL);
}
#endif

/*
 * Dispose of all character conversion objects in the archive object.
 */
void
archive_string_conversion_free(struct archive *a)
{
  struct archive_string_conv *sc; 
  struct archive_string_conv *sc_next; 

  for (sc = a->sconv; sc != NULL; sc = sc_next) {
    sc_next = sc->next;
    free_sconv_object(sc);
  }
  a->sconv = NULL;
  free(a->current_code);
  a->current_code = NULL;
}

/*
 * Return a conversion charset name.
 */
const char *
archive_string_conversion_charset_name(struct archive_string_conv *sc)
{
  if (sc == NULL) {
    return "current locale";
  }
  if (sc->flag & SCONV_TO_CHARSET)
    return (sc->to_charset);
  else
    return (sc->from_charset);
}

/*
 * Change the behavior of a string conversion.
 */
void
archive_string_conversion_set_opt(struct archive_string_conv *sc, int opt)
{
  switch (opt) {
  /*
   * A filename in UTF-8 was made with libarchive 2.x in a wrong
   * assumption that wchar_t was Unicode.
   * This option enables simulating the assumption in order to read
   * that filename correctly.
   */
  case SCONV_SET_OPT_UTF8_LIBARCHIVE2X:
#if (defined(_WIN32) && !defined(__CYGWIN__)) \
   || defined(__STDC_ISO_10646__) || defined(__APPLE__)
    /*
     * Nothing to do for it since wchar_t on these platforms
     * is really Unicode.
     */
    (void)sc; /* UNUSED */
#else
    if ((sc->flag & SCONV_UTF8_LIBARCHIVE_2) == 0) {
      sc->flag |= SCONV_UTF8_LIBARCHIVE_2;
      /* Set up string converters. */
      setup_converter(sc);
    }
#endif
    break;
  case SCONV_SET_OPT_NORMALIZATION_C:
    if ((sc->flag & SCONV_NORMALIZATION_C) == 0) {
      sc->flag |= SCONV_NORMALIZATION_C;
      sc->flag &= ~SCONV_NORMALIZATION_D;
      /* Set up string converters. */
      setup_converter(sc);
    }
    break;
  case SCONV_SET_OPT_NORMALIZATION_D:
#if defined(HAVE_ICONV)
    /*
     * If iconv will take the string, do not change the
     * setting of the normalization.
     */
    if (!(sc->flag & SCONV_WIN_CP) &&
         (sc->flag & (SCONV_FROM_UTF16 | SCONV_FROM_UTF8)) &&
        !(sc->flag & (SCONV_TO_UTF16 | SCONV_TO_UTF8)))
      break;
#endif
    if ((sc->flag & SCONV_NORMALIZATION_D) == 0) {
      sc->flag |= SCONV_NORMALIZATION_D;
      sc->flag &= ~SCONV_NORMALIZATION_C;
      /* Set up string converters. */
      setup_converter(sc);
    }
    break;
  default:
    break;
  }
}

/*
 *
 * Copy one archive_string to another in locale conversion.
 *
 *  archive_strncat_l();
 *  archive_strncpy_l();
 *
 */

static size_t
mbsnbytes(const void *_p, size_t n)
{
  size_t s;
  const char *p, *pp;

  if (_p == NULL)
    return (0);
  p = (const char *)_p;

  /* Like strlen(p), except won't examine positions beyond p[n]. */
  s = 0;
  pp = p;
  while (s < n && *pp) {
    pp++;
    s++;
  }
  return (s);
}

static size_t
utf16nbytes(const void *_p, size_t n)
{
  size_t s;
  const char *p, *pp;

  if (_p == NULL)
    return (0);
  p = (const char *)_p;

  /* Like strlen(p), except won't examine positions beyond p[n]. */
  s = 0;
  pp = p;
  n >>= 1;
  while (s < n && (pp[0] || pp[1])) {
    pp += 2;
    s++;
  }
  return (s<<1);
}

int
archive_strncpy_l(struct archive_string *as, const void *_p, size_t n,
    struct archive_string_conv *sc)
{
  as->length = 0;
  return (archive_strncat_l(as, _p, n, sc));
}

int
archive_strncat_l(struct archive_string *as, const void *_p, size_t n,
    struct archive_string_conv *sc)
{
  const void *s;
  size_t length = 0;
  int i, r = 0, r2;

  if (_p != NULL && n > 0) {
    if (sc != NULL && (sc->flag & SCONV_FROM_UTF16))
      length = utf16nbytes(_p, n);
    else
      length = mbsnbytes(_p, n);
  }

  /* We must allocate memory even if there is no data for conversion
   * or copy. This simulates archive_string_append behavior. */
  if (length == 0) {
    size_t tn = 1;
    if (sc != NULL && (sc->flag & SCONV_TO_UTF16))
      tn = 2;
    if (archive_string_ensure(as, as->length + tn) == NULL)
      return (-1);
    as->s[as->length] = 0;
    if (tn == 2)
      as->s[as->length+1] = 0;
    return (0);
  }

  /*
   * If sc is NULL, we just make a copy.
   */
  if (sc == NULL) {
    if (archive_string_append(as, _p, length) == NULL)
      return (-1);/* No memory */
    return (0);
  }

  s = _p;
  i = 0;
  if (sc->nconverter > 1) {
    sc->utftmp.length = 0;
    r2 = sc->converter[0](&(sc->utftmp), s, length, sc);
    if (r2 != 0 && errno == ENOMEM)
      return (r2);
    if (r > r2)
      r = r2;
    s = sc->utftmp.s;
    length = sc->utftmp.length;
    ++i;
  }
  r2 = sc->converter[i](as, s, length, sc);
  if (r > r2)
    r = r2;
  return (r);
}

struct archive_string *
archive_string_dirname(struct archive_string *as)
{
  /* strip trailing separators */
  while (as->length > 1 && as->s[as->length - 1] == '/')
    as->length--;
  /* strip final component */
  while (as->length > 0 && as->s[as->length - 1] != '/')
    as->length--;
  /* empty path -> cwd */
  if (as->length == 0)
    return (archive_strcat(as, "."));
  /* strip separator(s) */
  while (as->length > 1 && as->s[as->length - 1] == '/')
    as->length--;
  /* terminate */
  as->s[as->length] = '\0';
  return (as);
}

#if HAVE_ICONV

/*
 * Return -1 if conversion fails.
 */
static int
iconv_strncat_in_locale(struct archive_string *as, const void *_p,
    size_t length, struct archive_string_conv *sc)
{
  ICONV_CONST char *itp;
  size_t remaining;
  iconv_t cd;
  char *outp;
  size_t avail, bs;
  int return_value = 0; /* success */
  size_t to_size, from_size;

  if (sc->flag & SCONV_TO_UTF16)
    to_size = 2;
  else
    to_size = 1;
  if (sc->flag & SCONV_FROM_UTF16)
    from_size = 2;
  else
    from_size = 1;

  if (archive_string_ensure(as, as->length + length*2+to_size) == NULL)
    return (-1);

  cd = sc->cd;
  itp = (char *)(uintptr_t)_p;
  remaining = length;
  outp = as->s + as->length;
  avail = as->buffer_length - as->length - to_size;
  while (remaining >= from_size) {
    size_t result = iconv(cd, &itp, &remaining, &outp, &avail);

    if (result != (size_t)-1)
      break; /* Conversion completed. */

    if (errno == EILSEQ || errno == EINVAL) {
      /*
       * If an output charset is UTF-8 or UTF-16BE/LE,
       * unknown character should be U+FFFD
       * (replacement character).
       */
      if (sc->flag & (SCONV_TO_UTF8 | SCONV_TO_UTF16)) {
        size_t rbytes;
        if (sc->flag & SCONV_TO_UTF8)
          rbytes = sizeof(utf8_replacement_char);
        else
          rbytes = 2;

        if (avail < rbytes) {
          as->length = outp - as->s;
          bs = as->buffer_length +
              (remaining * to_size) + rbytes;
          if (NULL ==
              archive_string_ensure(as, bs))
            return (-1);
          outp = as->s + as->length;
          avail = as->buffer_length
              - as->length - to_size;
        }
        if (sc->flag & SCONV_TO_UTF8)
          memcpy(outp, utf8_replacement_char, sizeof(utf8_replacement_char));
        else if (sc->flag & SCONV_TO_UTF16BE)
          archive_be16enc(outp, UNICODE_R_CHAR);
        else
          archive_le16enc(outp, UNICODE_R_CHAR);
        outp += rbytes;
        avail -= rbytes;
      } else {
        /* Skip the illegal input bytes. */
        *outp++ = '?';
        avail--;
      }
      itp += from_size;
      remaining -= from_size;
      return_value = -1; /* failure */
    } else {
      /* E2BIG no output buffer,
       * Increase an output buffer.  */
      as->length = outp - as->s;
      bs = as->buffer_length + remaining * 2;
      if (NULL == archive_string_ensure(as, bs))
        return (-1);
      outp = as->s + as->length;
      avail = as->buffer_length - as->length - to_size;
    }
  }
  as->length = outp - as->s;
  as->s[as->length] = 0;
  if (to_size == 2)
    as->s[as->length+1] = 0;
  return (return_value);
}

#endif /* HAVE_ICONV */


#if defined(_WIN32) && !defined(__CYGWIN__)

/*
 * Translate a string from a some CodePage to an another CodePage by
 * Windows APIs, and copy the result. Return -1 if conversion fails.
 */
static int
strncat_in_codepage(struct archive_string *as,
    const void *_p, size_t length, struct archive_string_conv *sc)
{
  const char *s = (const char *)_p;
  struct archive_wstring aws;
  size_t l;
  int r, saved_flag;

  archive_string_init(&aws);
  saved_flag = sc->flag;
  sc->flag &= ~(SCONV_NORMALIZATION_D | SCONV_NORMALIZATION_C);
  r = archive_wstring_append_from_mbs_in_codepage(&aws, s, length, sc);
  sc->flag = saved_flag;
  if (r != 0) {
    archive_wstring_free(&aws);
    if (errno != ENOMEM)
      archive_string_append(as, s, length);
    return (-1);
  }

  l = as->length;
  r = archive_string_append_from_wcs_in_codepage(
      as, aws.s, aws.length, sc);
  if (r != 0 && errno != ENOMEM && l == as->length)
    archive_string_append(as, s, length);
  archive_wstring_free(&aws);
  return (r);
}

/*
 * Test whether MBS ==> WCS is okay.
 */
static int
invalid_mbs(const void *_p, size_t n, struct archive_string_conv *sc)
{
  const char *p = (const char *)_p;
  unsigned codepage;
  DWORD mbflag = MB_ERR_INVALID_CHARS;

  if (sc->flag & SCONV_FROM_CHARSET)
    codepage = sc->to_cp;
  else
    codepage = sc->from_cp;

  if (codepage == CP_C_LOCALE)
    return (0);
  if (codepage != CP_UTF8)
    mbflag |= MB_PRECOMPOSED;

  if (n > (size_t)INT_MAX)
    return (-1); /* Invalid */
  if (MultiByteToWideChar(codepage, mbflag, p, (int)n, NULL, 0) == 0)
    return (-1); /* Invalid */
  return (0); /* Okay */
}

#else

/*
 * Test whether MBS ==> WCS is okay.
 */
static int
invalid_mbs(const void *_p, size_t n, struct archive_string_conv *sc)
{
  const char *p = (const char *)_p;
  size_t r;

#if HAVE_MBRTOWC
  mbstate_t shift_state;

  memset(&shift_state, 0, sizeof(shift_state));
#else
  /* Clear the shift state before starting. */
  mbtowc(NULL, NULL, 0);
#endif
  while (n) {
    wchar_t wc;

#if HAVE_MBRTOWC
    r = mbrtowc(&wc, p, n, &shift_state);
#else
    r = mbtowc(&wc, p, n);
#endif
    if (r == (size_t)-1 || r == (size_t)-2)
      return (-1);/* Invalid. */
    if (r == 0)
      break;
    p += r;
    n -= r;
  }
  (void)sc; /* UNUSED */
  return (0); /* All Okey. */
}

#endif /* defined(_WIN32) && !defined(__CYGWIN__) */

/*
 * Basically returns -1 because we cannot make a conversion of charset
 * without iconv but in some cases this would return 0.
 * Returns 0 if all copied characters are ASCII.
 * Returns 0 if both from-locale and to-locale are the same and those
 * can be WCS with no error.
 */
static int
best_effort_strncat_in_locale(struct archive_string *as, const void *_p,
    size_t length, struct archive_string_conv *sc)
{
  size_t remaining;
  const uint8_t *itp;
  int return_value = 0; /* success */

  /*
   * If both from-locale and to-locale is the same, this makes a copy.
   * And then this checks all copied MBS can be WCS if so returns 0.
   */
  if (sc->same) {
    if (archive_string_append(as, _p, length) == NULL)
      return (-1);/* No memory */
    return (invalid_mbs(_p, length, sc));
  }

  /*
   * If a character is ASCII, this just copies it. If not, this
   * assigns '?' character instead but in UTF-8 locale this assigns
   * byte sequence 0xEF 0xBD 0xBD, which are code point U+FFFD,
   * a Replacement Character in Unicode.
   */

  remaining = length;
  itp = (const uint8_t *)_p;
  while (*itp && remaining > 0) {
    if (*itp > 127) {
      // Non-ASCII: Substitute with suitable replacement
      if (sc->flag & SCONV_TO_UTF8) {
        if (archive_string_append(as, utf8_replacement_char, sizeof(utf8_replacement_char)) == NULL) {
          __archive_errx(1, "Out of memory");
        }
      } else {
        archive_strappend_char(as, '?');
      }
      return_value = -1;
    } else {
      archive_strappend_char(as, *itp);
    }
    ++itp;
  }
  return (return_value);
}


/*
 * Unicode conversion functions.
 *   - UTF-8 <===> UTF-8 in removing surrogate pairs.
 *   - UTF-8 NFD ===> UTF-8 NFC in removing surrogate pairs.
 *   - UTF-8 made by libarchive 2.x ===> UTF-8.
 *   - UTF-16BE <===> UTF-8.
 *
 */

/*
 * Utility to convert a single UTF-8 sequence.
 *
 * Usually return used bytes, return used byte in negative value when
 * a unicode character is replaced with U+FFFD.
 * See also http://unicode.org/review/pr-121.html Public Review Issue #121
 * Recommended Practice for Replacement Characters.
 */
static int
_utf8_to_unicode(uint32_t *pwc, const char *s, size_t n)
{
  static const char utf8_count[256] = {
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 00 - 0F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 10 - 1F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 20 - 2F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 30 - 3F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 40 - 4F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 50 - 5F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 60 - 6F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,/* 70 - 7F */
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,/* 80 - 8F */
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,/* 90 - 9F */
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,/* A0 - AF */
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,/* B0 - BF */
     0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,/* C0 - CF */
     2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,/* D0 - DF */
     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,/* E0 - EF */
     4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 /* F0 - FF */
  };
  int ch, i;
  int cnt;
  uint32_t wc;

  /* Sanity check. */
  if (n == 0)
    return (0);
  /*
   * Decode 1-4 bytes depending on the value of the first byte.
   */
  ch = (unsigned char)*s;
  if (ch == 0)
    return (0); /* Standard:  return 0 for end-of-string. */
  cnt = utf8_count[ch];

  /* Invalid sequence or there are not plenty bytes. */
  if (n < (size_t)cnt) {
    cnt = (int)n;
    for (i = 1; i < cnt; i++) {
      if ((s[i] & 0xc0) != 0x80) {
        cnt = i;
        break;
      }
    }
    goto invalid_sequence;
  }

  /* Make a Unicode code point from a single UTF-8 sequence. */
  switch (cnt) {
  case 1: /* 1 byte sequence. */
    *pwc = ch & 0x7f;
    return (cnt);
  case 2: /* 2 bytes sequence. */
    if ((s[1] & 0xc0) != 0x80) {
      cnt = 1;
      goto invalid_sequence;
    }
    *pwc = ((ch & 0x1f) << 6) | (s[1] & 0x3f);
    return (cnt);
  case 3: /* 3 bytes sequence. */
    if ((s[1] & 0xc0) != 0x80) {
      cnt = 1;
      goto invalid_sequence;
    }
    if ((s[2] & 0xc0) != 0x80) {
      cnt = 2;
      goto invalid_sequence;
    }
    wc = ((ch & 0x0f) << 12)
        | ((s[1] & 0x3f) << 6)
        | (s[2] & 0x3f);
    if (wc < 0x800)
      goto invalid_sequence;/* Overlong sequence. */
    break;
  case 4: /* 4 bytes sequence. */
    if ((s[1] & 0xc0) != 0x80) {
      cnt = 1;
      goto invalid_sequence;
    }
    if ((s[2] & 0xc0) != 0x80) {
      cnt = 2;
      goto invalid_sequence;
    }
    if ((s[3] & 0xc0) != 0x80) {
      cnt = 3;
      goto invalid_sequence;
    }
    wc = ((ch & 0x07) << 18)
        | ((s[1] & 0x3f) << 12)
        | ((s[2] & 0x3f) << 6)
        | (s[3] & 0x3f);
    if (wc < 0x10000)
      goto invalid_sequence;/* Overlong sequence. */
    break;
  default: /* Others are all invalid sequence. */
    if (ch == 0xc0 || ch == 0xc1)
      cnt = 2;
    else if (ch >= 0xf5 && ch <= 0xf7)
      cnt = 4;
    else if (ch >= 0xf8 && ch <= 0xfb)
      cnt = 5;
    else if (ch == 0xfc || ch == 0xfd)
      cnt = 6;
    else
      cnt = 1;
    if (n < (size_t)cnt)
      cnt = (int)n;
    for (i = 1; i < cnt; i++) {
      if ((s[i] & 0xc0) != 0x80) {
        cnt = i;
        break;
      }
    }
    goto invalid_sequence;
  }

  /* The code point larger than 0x10FFFF is not legal
   * Unicode values. */
  if (wc > UNICODE_MAX)
    goto invalid_sequence;
  /* Correctly gets a Unicode, returns used bytes. */
  *pwc = wc;
  return (cnt);
invalid_sequence:
  *pwc = UNICODE_R_CHAR;/* set the Replacement Character instead. */
  return (cnt * -1);
}

static int
utf8_to_unicode(uint32_t *pwc, const char *s, size_t n)
{
  int cnt;

  cnt = _utf8_to_unicode(pwc, s, n);
  /* Any of Surrogate pair is not legal Unicode values. */
  if (cnt == 3 && IS_SURROGATE_PAIR_LA(*pwc))
    return (-3);
  return (cnt);
}

static inline uint32_t
combine_surrogate_pair(uint32_t uc, uint32_t uc2)
{
  uc -= 0xD800;
  uc *= 0x400;
  uc += uc2 - 0xDC00;
  uc += 0x10000;
  return (uc);
}

/*
 * Convert a single UTF-8/CESU-8 sequence to a Unicode code point in
 * removing surrogate pairs.
 *
 * CESU-8: The Compatibility Encoding Scheme for UTF-16.
 *
 * Usually return used bytes, return used byte in negative value when
 * a unicode character is replaced with U+FFFD.
 */
static int
cesu8_to_unicode(uint32_t *pwc, const char *s, size_t n)
{
  uint32_t wc = 0;
  int cnt;

  cnt = _utf8_to_unicode(&wc, s, n);
  if (cnt == 3 && IS_HIGH_SURROGATE_LA(wc)) {
    uint32_t wc2 = 0;
    if (n - 3 < 3) {
      /* Invalid byte sequence. */
      goto invalid_sequence;
    }
    cnt = _utf8_to_unicode(&wc2, s+3, n-3);
    if (cnt != 3 || !IS_LOW_SURROGATE_LA(wc2)) {
      /* Invalid byte sequence. */
      goto invalid_sequence;
    }
    wc = combine_surrogate_pair(wc, wc2);
    cnt = 6;
  } else if (cnt == 3 && IS_LOW_SURROGATE_LA(wc)) {
    /* Invalid byte sequence. */
    goto invalid_sequence;
  }
  *pwc = wc;
  return (cnt);
invalid_sequence:
  *pwc = UNICODE_R_CHAR;/* set the Replacement Character instead. */
  if (cnt > 0)
    cnt *= -1;
  return (cnt);
}

/*
 * Convert a Unicode code point to a single UTF-8 sequence.
 *
 * NOTE:This function does not check if the Unicode is legal or not.
 * Please you definitely check it before calling this.
 */
static size_t
unicode_to_utf8(char *p, size_t remaining, uint32_t uc)
{
  char *_p = p;

  /* Invalid Unicode char maps to Replacement character */
  if (uc > UNICODE_MAX)
    uc = UNICODE_R_CHAR;
  /* Translate code point to UTF8 */
  if (uc <= 0x7f) {
    if (remaining == 0)
      return (0);
    *p++ = (char)uc;
  } else if (uc <= 0x7ff) {
    if (remaining < 2)
      return (0);
    *p++ = 0xc0 | ((uc >> 6) & 0x1f);
    *p++ = 0x80 | (uc & 0x3f);
  } else if (uc <= 0xffff) {
    if (remaining < 3)
      return (0);
    *p++ = 0xe0 | ((uc >> 12) & 0x0f);
    *p++ = 0x80 | ((uc >> 6) & 0x3f);
    *p++ = 0x80 | (uc & 0x3f);
  } else {
    if (remaining < 4)
      return (0);
    *p++ = 0xf0 | ((uc >> 18) & 0x07);
    *p++ = 0x80 | ((uc >> 12) & 0x3f);
    *p++ = 0x80 | ((uc >> 6) & 0x3f);
    *p++ = 0x80 | (uc & 0x3f);
  }
  return (p - _p);
}

static int
utf16be_to_unicode(uint32_t *pwc, const char *s, size_t n)
{
  return (utf16_to_unicode(pwc, s, n, 1));
}

static int
utf16le_to_unicode(uint32_t *pwc, const char *s, size_t n)
{
  return (utf16_to_unicode(pwc, s, n, 0));
}

static int
utf16_to_unicode(uint32_t *pwc, const char *s, size_t n, int be)
{
  const char *utf16 = s;
  unsigned uc;

  if (n == 0)
    return (0);
  if (n == 1) {
    /* set the Replacement Character instead. */
    *pwc = UNICODE_R_CHAR;
    return (-1);
  }

  if (be)
    uc = archive_be16dec(utf16);
  else
    uc = archive_le16dec(utf16);
  utf16 += 2;
    
  /* If this is a surrogate pair, assemble the full code point.*/
  if (IS_HIGH_SURROGATE_LA(uc)) {
    unsigned uc2;

    if (n >= 4) {
      if (be)
        uc2 = archive_be16dec(utf16);
      else
        uc2 = archive_le16dec(utf16);
    } else
      uc2 = 0;
    if (IS_LOW_SURROGATE_LA(uc2)) {
      uc = combine_surrogate_pair(uc, uc2);
      utf16 += 2;
    } else {
      /* Undescribed code point should be U+FFFD
      * (replacement character). */
      *pwc = UNICODE_R_CHAR;
      return (-2);
    }
  }

  /*
   * Surrogate pair values(0xd800 through 0xdfff) are only
   * used by UTF-16, so, after above calculation, the code
   * must not be surrogate values, and Unicode has no codes
   * larger than 0x10ffff. Thus, those are not legal Unicode
   * values.
   */
  if (IS_SURROGATE_PAIR_LA(uc) || uc > UNICODE_MAX) {
    /* Undescribed code point should be U+FFFD
    * (replacement character). */
    *pwc = UNICODE_R_CHAR;
    return (((int)(utf16 - s)) * -1);
  }
  *pwc = uc;
  return ((int)(utf16 - s));
}

static size_t
unicode_to_utf16be(char *p, size_t remaining, uint32_t uc)
{
  char *utf16 = p;

  if (uc > 0xffff) {
    /* We have a code point that won't fit into a
     * wchar_t; convert it to a surrogate pair. */
    if (remaining < 4)
      return (0);
    uc -= 0x10000;
    archive_be16enc(utf16, ((uc >> 10) & 0x3ff) + 0xD800);
    archive_be16enc(utf16+2, (uc & 0x3ff) + 0xDC00);
    return (4);
  } else {
    if (remaining < 2)
      return (0);
    archive_be16enc(utf16, (uint16_t)uc);
    return (2);
  }
}

static size_t
unicode_to_utf16le(char *p, size_t remaining, uint32_t uc)
{
  char *utf16 = p;

  if (uc > 0xffff) {
    /* We have a code point that won't fit into a
     * wchar_t; convert it to a surrogate pair. */
    if (remaining < 4)
      return (0);
    uc -= 0x10000;
    archive_le16enc(utf16, ((uc >> 10) & 0x3ff) + 0xD800);
    archive_le16enc(utf16+2, (uc & 0x3ff) + 0xDC00);
    return (4);
  } else {
    if (remaining < 2)
      return (0);
    archive_le16enc(utf16, (uint16_t)uc);
    return (2);
  }
}

/*
 * Append new UTF-8 string to existing UTF-8 string.
 * Existing string is assumed to already be in proper form;
 * the new string will have invalid sequences replaced and
 * surrogate pairs canonicalized.
 */
static int
strncat_from_utf8_to_utf8(struct archive_string *as, const void *_src,
    size_t len, struct archive_string_conv *sc)
{
  int ret = 0;
  const char *src = _src;
  (void)sc; /* UNUSED */

  /* Pre-extend the destination */
  if (archive_string_ensure(as, as->length + len + 1) == NULL)
    return (-1);

  /* Invariant: src points to the first UTF8 byte that hasn't
   * been copied to the destination `as`. */
  for (;;) {
    int n;
    uint32_t uc;
    const char *e = src;

    /* Skip UTF-8 sequences until we reach end-of-string or
     * a code point that needs conversion. */
    while ((n = utf8_to_unicode(&uc, e, len)) > 0) {
      e += n;
      len -= n;
    }
    /* Copy the part that doesn't need conversion */
    if (e > src) {
      if (archive_string_append(as, src, e - src) == NULL)
        return (-1);
      src = e;
    }

    if (n == 0) {
      /* We reached end-of-string */
      return (ret);
    } else {
      /* Next code point needs conversion */
      char t[4];
      size_t w;

      /* Try decoding a surrogate pair */
      if (n == -3 && IS_SURROGATE_PAIR_LA(uc)) {
        n = cesu8_to_unicode(&uc, src, len);
      }
      /* Not a (valid) surrogate, so use a replacement char */
      if (n < 0) {
        ret = -1; /* Return -1 if we used any replacement */
        n *= -1;
      }
      /* Consume converted code point */
      src += n;
      len -= n;
      /* Convert and append new UTF-8 sequence. */
      w = unicode_to_utf8(t, sizeof(t), uc);
      if (archive_string_append(as, t, w) == NULL)
        return (-1);
    }
  }
}

static int
archive_string_append_unicode(struct archive_string *as, const void *_p,
    size_t len, struct archive_string_conv *sc)
{
  const char *s;
  char *p, *endp;
  uint32_t uc;
  size_t w;
  size_t ts, tm;
  int n, ret = 0;
  int (*parse)(uint32_t *, const char *, size_t);
  size_t (*unparse)(char *, size_t, uint32_t);

  if (sc->flag & SCONV_TO_UTF16BE) {
    unparse = unicode_to_utf16be;
    ts = 2;
  } else if (sc->flag & SCONV_TO_UTF16LE) {
    unparse = unicode_to_utf16le;
    ts = 2;
  } else if (sc->flag & SCONV_TO_UTF8) {
    unparse = unicode_to_utf8;
    ts = 1;
  } else {
    /*
     * This case is going to be converted to another
     * character-set through iconv.
     */
    if (sc->flag & SCONV_FROM_UTF16BE) {
      unparse = unicode_to_utf16be;
      ts = 2;
    } else if (sc->flag & SCONV_FROM_UTF16LE) {
      unparse = unicode_to_utf16le;
      ts = 2;
    } else {
      unparse = unicode_to_utf8;
      ts = 1;
    }
  }

  if (sc->flag & SCONV_FROM_UTF16BE) {
    parse = utf16be_to_unicode;
    tm = 1;
  } else if (sc->flag & SCONV_FROM_UTF16LE) {
    parse = utf16le_to_unicode;
    tm = 1;
  } else {
    parse = cesu8_to_unicode;
    tm = ts;
  }

  if (archive_string_ensure(as, as->length + len * tm + ts) == NULL)
    return (-1);

  s = (const char *)_p;
  p = as->s + as->length;
  endp = as->s + as->buffer_length - ts;
  while ((n = parse(&uc, s, len)) != 0) {
    if (n < 0) {
      /* Use a replaced unicode character. */
      n *= -1;
      ret = -1;
    }
    s += n;
    len -= n;
    while ((w = unparse(p, endp - p, uc)) == 0) {
      /* There is not enough output buffer so
       * we have to expand it. */
      as->length = p - as->s;
      if (archive_string_ensure(as,
          as->buffer_length + len * tm + ts) == NULL)
        return (-1);
      p = as->s + as->length;
      endp = as->s + as->buffer_length - ts;
    }
    p += w;
  }
  as->length = p - as->s;
  as->s[as->length] = '\0';
  if (ts == 2)
    as->s[as->length+1] = '\0';
  return (ret);
}

/*
 * Following Constants for Hangul compositions this information comes from
 * Unicode Standard Annex #15  http://unicode.org/reports/tr15/
 */
#define HC_SBASE  0xAC00
#define HC_LBASE  0x1100
#define HC_VBASE  0x1161
#define HC_TBASE  0x11A7
#define HC_LCOUNT 19
#define HC_VCOUNT 21
#define HC_TCOUNT 28
#define HC_NCOUNT (HC_VCOUNT * HC_TCOUNT)
#define HC_SCOUNT (HC_LCOUNT * HC_NCOUNT)

static uint32_t
get_nfc(uint32_t uc, uint32_t uc2)
{
  int t, b;

  t = 0;
  b = sizeof(u_composition_table)/sizeof(u_composition_table[0]) -1;
  while (b >= t) {
    int m = (t + b) / 2;
    if (u_composition_table[m].cp1 < uc)
      t = m + 1;
    else if (u_composition_table[m].cp1 > uc)
      b = m - 1;
    else if (u_composition_table[m].cp2 < uc2)
      t = m + 1;
    else if (u_composition_table[m].cp2 > uc2)
      b = m - 1;
    else
      return (u_composition_table[m].nfc);
  }
  return (0);
}

#define FDC_MAX 10  /* The maximum number of Following Decomposable
       * Characters. */

/*
 * Update first code point.
 */
#define UPDATE_UC(new_uc) do {   \
  uc = new_uc;        \
  ucptr = NULL;       \
} while (0)

/*
 * Replace first code point with second code point.
 */
#define REPLACE_UC_WITH_UC2() do {   \
  uc = uc2;       \
  ucptr = uc2ptr;       \
  n = n2;         \
} while (0)

#define EXPAND_BUFFER() do {     \
  as->length = p - as->s;     \
  if (archive_string_ensure(as,   \
      as->buffer_length + len * tm + ts) == NULL)\
    return (-1);     \
  p = as->s + as->length;     \
  endp = as->s + as->buffer_length - ts;  \
} while (0)

#define UNPARSE(p, endp, uc)  do {   \
  while ((w = unparse(p, (endp) - (p), uc)) == 0) {\
    EXPAND_BUFFER();   \
  }          \
  p += w;         \
} while (0)

/*
 * Write first code point.
 * If the code point has not be changed from its original code,
 * this just copies it from its original buffer pointer.
 * If not, this converts it to UTF-8 byte sequence and copies it.
 */
#define WRITE_UC()  do {     \
  if (ucptr) {       \
    if (p + n > endp)   \
      EXPAND_BUFFER(); \
    switch (n) {     \
    case 4:       \
      *p++ = *ucptr++;  \
      /* FALL THROUGH */  \
    case 3:       \
      *p++ = *ucptr++;  \
      /* FALL THROUGH */  \
    case 2:       \
      *p++ = *ucptr++;  \
      /* FALL THROUGH */  \
    case 1:       \
      *p++ = *ucptr;    \
      break;     \
    }       \
    ucptr = NULL;     \
  } else {       \
    UNPARSE(p, endp, uc);    \
  }          \
} while (0)

/*
 * Collect following decomposable code points.
 */
#define COLLECT_CPS(start)  do {   \
  int _i;         \
  for (_i = start; _i < FDC_MAX ; _i++) { \
    nx = parse(&ucx[_i], s, len); \
    if (nx <= 0)     \
      break;     \
    cx = CCC(ucx[_i]);    \
    if (cl >= cx && cl != 228 && cx != 228)\
      break;     \
    s += nx;      \
    len -= nx;      \
    cl = cx;      \
    ccx[_i] = cx;     \
  }          \
  if (_i >= FDC_MAX) {     \
    ret = -1;     \
    ucx_size = FDC_MAX;   \
  } else         \
    ucx_size = _i;     \
} while (0)

/*
 * Normalize UTF-8/UTF-16BE characters to Form C and copy the result.
 *
 * TODO: Convert composition exclusions, which are never converted
 * from NFC,NFD,NFKC and NFKD, to Form C.
 */
static int
archive_string_normalize_C(struct archive_string *as, const void *_p,
    size_t len, struct archive_string_conv *sc)
{
  const char *s = (const char *)_p;
  char *p, *endp;
  uint32_t uc, uc2;
  size_t w;
  int always_replace, n, n2, ret = 0, spair, ts, tm;
  int (*parse)(uint32_t *, const char *, size_t);
  size_t (*unparse)(char *, size_t, uint32_t);

  always_replace = 1;
  ts = 1;/* text size. */
  if (sc->flag & SCONV_TO_UTF16BE) {
    unparse = unicode_to_utf16be;
    ts = 2;
    if (sc->flag & SCONV_FROM_UTF16BE)
      always_replace = 0;
  } else if (sc->flag & SCONV_TO_UTF16LE) {
    unparse = unicode_to_utf16le;
    ts = 2;
    if (sc->flag & SCONV_FROM_UTF16LE)
      always_replace = 0;
  } else if (sc->flag & SCONV_TO_UTF8) {
    unparse = unicode_to_utf8;
    if (sc->flag & SCONV_FROM_UTF8)
      always_replace = 0;
  } else {
    /*
     * This case is going to be converted to another
     * character-set through iconv.
     */
    always_replace = 0;
    if (sc->flag & SCONV_FROM_UTF16BE) {
      unparse = unicode_to_utf16be;
      ts = 2;
    } else if (sc->flag & SCONV_FROM_UTF16LE) {
      unparse = unicode_to_utf16le;
      ts = 2;
    } else {
      unparse = unicode_to_utf8;
    }
  }

  if (sc->flag & SCONV_FROM_UTF16BE) {
    parse = utf16be_to_unicode;
    tm = 1;
    spair = 4;/* surrogate pair size in UTF-16. */
  } else if (sc->flag & SCONV_FROM_UTF16LE) {
    parse = utf16le_to_unicode;
    tm = 1;
    spair = 4;/* surrogate pair size in UTF-16. */
  } else {
    parse = cesu8_to_unicode;
    tm = ts;
    spair = 6;/* surrogate pair size in UTF-8. */
  }

  if (archive_string_ensure(as, as->length + len * tm + ts) == NULL)
    return (-1);

  p = as->s + as->length;
  endp = as->s + as->buffer_length - ts;
  while ((n = parse(&uc, s, len)) != 0) {
    const char *ucptr, *uc2ptr;

    if (n < 0) {
      /* Use a replaced unicode character. */
      UNPARSE(p, endp, uc);
      s += n*-1;
      len -= n*-1;
      ret = -1;
      continue;
    } else if (n == spair || always_replace)
      /* uc is converted from a surrogate pair.
       * this should be treated as a changed code. */
      ucptr = NULL;
    else
      ucptr = s;
    s += n;
    len -= n;

    /* Read second code point. */
    while ((n2 = parse(&uc2, s, len)) > 0) {
      uint32_t ucx[FDC_MAX];
      int ccx[FDC_MAX];
      int cl, cx, i, nx, ucx_size;
      int LIndex,SIndex;
      uint32_t nfc;

      if (n2 == spair || always_replace)
        /* uc2 is converted from a surrogate pair.
         * this should be treated as a changed code. */
        uc2ptr = NULL;
      else
        uc2ptr = s;
      s += n2;
      len -= n2;

      /*
       * If current second code point is out of decomposable
       * code points, finding compositions is unneeded.
       */
      if (!IS_DECOMPOSABLE_BLOCK(uc2)) {
        WRITE_UC();
        REPLACE_UC_WITH_UC2();
        continue;
      }

      /*
       * Try to combine current code points.
       */
      /*
       * We have to combine Hangul characters according to
       * http://uniicode.org/reports/tr15/#Hangul
       */
      if (0 <= (LIndex = uc - HC_LBASE) &&
          LIndex < HC_LCOUNT) {
        /*
         * Hangul Composition.
         * 1. Two current code points are L and V.
         */
        int VIndex = uc2 - HC_VBASE;
        if (0 <= VIndex && VIndex < HC_VCOUNT) {
          /* Make syllable of form LV. */
          UPDATE_UC(HC_SBASE +
              (LIndex * HC_VCOUNT + VIndex) *
               HC_TCOUNT);
        } else {
          WRITE_UC();
          REPLACE_UC_WITH_UC2();
        }
        continue;
      } else if (0 <= (SIndex = uc - HC_SBASE) &&
          SIndex < HC_SCOUNT && (SIndex % HC_TCOUNT) == 0) {
        /*
         * Hangul Composition.
         * 2. Two current code points are LV and T.
         */
        int TIndex = uc2 - HC_TBASE;
        if (0 < TIndex && TIndex < HC_TCOUNT) {
          /* Make syllable of form LVT. */
          UPDATE_UC(uc + TIndex);
        } else {
          WRITE_UC();
          REPLACE_UC_WITH_UC2();
        }
        continue;
      } else if ((nfc = get_nfc(uc, uc2)) != 0) {
        /* A composition to current code points
         * is found. */
        UPDATE_UC(nfc);
        continue;
      } else if ((cl = CCC(uc2)) == 0) {
        /* Clearly 'uc2' the second code point is not
         * a decomposable code. */
        WRITE_UC();
        REPLACE_UC_WITH_UC2();
        continue;
      }

      /*
       * Collect following decomposable code points.
       */
      cx = 0;
      ucx[0] = uc2;
      ccx[0] = cl;
      COLLECT_CPS(1);

      /*
       * Find a composed code in the collected code points.
       */
      i = 1;
      while (i < ucx_size) {
        int j;

        if ((nfc = get_nfc(uc, ucx[i])) == 0) {
          i++;
          continue;
        }

        /*
         * nfc is composed of uc and ucx[i].
         */
        UPDATE_UC(nfc);

        /*
         * Remove ucx[i] by shifting
         * following code points.
         */
        for (j = i; j+1 < ucx_size; j++) {
          ucx[j] = ucx[j+1];
          ccx[j] = ccx[j+1];
        }
        ucx_size --;

        /*
         * Collect following code points blocked
         * by ucx[i] the removed code point.
         */
        if (ucx_size > 0 && i == ucx_size &&
            nx > 0 && cx == cl) {
          cl =  ccx[ucx_size-1];
          COLLECT_CPS(ucx_size);
        }
        /*
         * Restart finding a composed code with
         * the updated uc from the top of the
         * collected code points.
         */
        i = 0;
      }

      /*
       * Apparently the current code points are not
       * decomposed characters or already composed.
       */
      WRITE_UC();
      for (i = 0; i < ucx_size; i++)
        UNPARSE(p, endp, ucx[i]);

      /*
       * Flush out remaining canonical combining characters.
       */
      if (nx > 0 && cx == cl && len > 0) {
        while ((nx = parse(&ucx[0], s, len))
            > 0) {
          cx = CCC(ucx[0]);
          if (cl > cx)
            break;
          s += nx;
          len -= nx;
          cl = cx;
          UNPARSE(p, endp, ucx[0]);
        }
      }
      break;
    }
    if (n2 < 0) {
      WRITE_UC();
      /* Use a replaced unicode character. */
      UNPARSE(p, endp, uc2);
      s += n2*-1;
      len -= n2*-1;
      ret = -1;
      continue;
    } else if (n2 == 0) {
      WRITE_UC();
      break;
    }
  }
  as->length = p - as->s;
  as->s[as->length] = '\0';
  if (ts == 2)
    as->s[as->length+1] = '\0';
  return (ret);
}

static int
get_nfd(uint32_t *cp1, uint32_t *cp2, uint32_t uc)
{
  int t, b;

  /*
   * These are not converted to NFD on Mac OS.
   */
  if ((uc >= 0x2000 && uc <= 0x2FFF) ||
      (uc >= 0xF900 && uc <= 0xFAFF) ||
      (uc >= 0x2F800 && uc <= 0x2FAFF))
    return (0);
  /*
   * Those code points are not converted to NFD on Mac OS.
   * I do not know the reason because it is undocumented.
   *   NFC        NFD
   *   1109A  ==> 11099 110BA
   *   1109C  ==> 1109B 110BA
   *   110AB  ==> 110A5 110BA
   */
  if (uc == 0x1109A || uc == 0x1109C || uc == 0x110AB)
    return (0);

  t = 0;
  b = sizeof(u_decomposition_table)/sizeof(u_decomposition_table[0]) -1;
  while (b >= t) {
    int m = (t + b) / 2;
    if (u_decomposition_table[m].nfc < uc)
      t = m + 1;
    else if (u_decomposition_table[m].nfc > uc)
      b = m - 1;
    else {
      *cp1 = u_decomposition_table[m].cp1;
      *cp2 = u_decomposition_table[m].cp2;
      return (1);
    }
  }
  return (0);
}

#define REPLACE_UC_WITH(cp) do {   \
  uc = cp;        \
  ucptr = NULL;       \
} while (0)

/*
 * Normalize UTF-8 characters to Form D and copy the result.
 */
static int
archive_string_normalize_D(struct archive_string *as, const void *_p,
    size_t len, struct archive_string_conv *sc)
{
  const char *s = (const char *)_p;
  char *p, *endp;
  uint32_t uc, uc2;
  size_t w;
  int always_replace, n, n2, ret = 0, spair, ts, tm;
  int (*parse)(uint32_t *, const char *, size_t);
  size_t (*unparse)(char *, size_t, uint32_t);

  always_replace = 1;
  ts = 1;/* text size. */
  if (sc->flag & SCONV_TO_UTF16BE) {
    unparse = unicode_to_utf16be;
    ts = 2;
    if (sc->flag & SCONV_FROM_UTF16BE)
      always_replace = 0;
  } else if (sc->flag & SCONV_TO_UTF16LE) {
    unparse = unicode_to_utf16le;
    ts = 2;
    if (sc->flag & SCONV_FROM_UTF16LE)
      always_replace = 0;
  } else if (sc->flag & SCONV_TO_UTF8) {
    unparse = unicode_to_utf8;
    if (sc->flag & SCONV_FROM_UTF8)
      always_replace = 0;
  } else {
    /*
     * This case is going to be converted to another
     * character-set through iconv.
     */
    always_replace = 0;
    if (sc->flag & SCONV_FROM_UTF16BE) {
      unparse = unicode_to_utf16be;
      ts = 2;
    } else if (sc->flag & SCONV_FROM_UTF16LE) {
      unparse = unicode_to_utf16le;
      ts = 2;
    } else {
      unparse = unicode_to_utf8;
    }
  }

  if (sc->flag & SCONV_FROM_UTF16BE) {
    parse = utf16be_to_unicode;
    tm = 1;
    spair = 4;/* surrogate pair size in UTF-16. */
  } else if (sc->flag & SCONV_FROM_UTF16LE) {
    parse = utf16le_to_unicode;
    tm = 1;
    spair = 4;/* surrogate pair size in UTF-16. */
  } else {
    parse = cesu8_to_unicode;
    tm = ts;
    spair = 6;/* surrogate pair size in UTF-8. */
  }

  if (archive_string_ensure(as, as->length + len * tm + ts) == NULL)
    return (-1);

  p = as->s + as->length;
  endp = as->s + as->buffer_length - ts;
  while ((n = parse(&uc, s, len)) != 0) {
    const char *ucptr;
    uint32_t cp1, cp2;
    int SIndex;
    struct {
      uint32_t uc;
      int ccc;
    } fdc[FDC_MAX];
    int fdi, fdj;
    int ccc;

check_first_code:
    if (n < 0) {
      /* Use a replaced unicode character. */
      UNPARSE(p, endp, uc);
      s += n*-1;
      len -= n*-1;
      ret = -1;
      continue;
    } else if (n == spair || always_replace)
      /* uc is converted from a surrogate pair.
       * this should be treated as a changed code. */
      ucptr = NULL;
    else
      ucptr = s;
    s += n;
    len -= n;

    /* Hangul Decomposition. */
    if ((SIndex = uc - HC_SBASE) >= 0 && SIndex < HC_SCOUNT) {
      int L = HC_LBASE + SIndex / HC_NCOUNT;
      int V = HC_VBASE + (SIndex % HC_NCOUNT) / HC_TCOUNT;
      int T = HC_TBASE + SIndex % HC_TCOUNT;

      REPLACE_UC_WITH(L);
      WRITE_UC();
      REPLACE_UC_WITH(V);
      WRITE_UC();
      if (T != HC_TBASE) {
        REPLACE_UC_WITH(T);
        WRITE_UC();
      }
      continue;
    }
    if (IS_DECOMPOSABLE_BLOCK(uc) && CCC(uc) != 0) {
      WRITE_UC();
      continue;
    }

    fdi = 0;
    while (get_nfd(&cp1, &cp2, uc) && fdi < FDC_MAX) {
      int k;

      for (k = fdi; k > 0; k--)
        fdc[k] = fdc[k-1];
      fdc[0].ccc = CCC(cp2);
      fdc[0].uc = cp2;
      fdi++;
      REPLACE_UC_WITH(cp1);
    }

    /* Read following code points. */
    while ((n2 = parse(&uc2, s, len)) > 0 &&
        (ccc = CCC(uc2)) != 0 && fdi < FDC_MAX) {
      int j, k;

      s += n2;
      len -= n2;
      for (j = 0; j < fdi; j++) {
        if (fdc[j].ccc > ccc)
          break;
      }
      if (j < fdi) {
        for (k = fdi; k > j; k--)
          fdc[k] = fdc[k-1];
        fdc[j].ccc = ccc;
        fdc[j].uc = uc2;
      } else {
        fdc[fdi].ccc = ccc;
        fdc[fdi].uc = uc2;
      }
      fdi++;
    }

    WRITE_UC();
    for (fdj = 0; fdj < fdi; fdj++) {
      REPLACE_UC_WITH(fdc[fdj].uc);
      WRITE_UC();
    }

    if (n2 == 0)
      break;
    REPLACE_UC_WITH(uc2);
    n = n2;
    goto check_first_code;
  }
  as->length = p - as->s;
  as->s[as->length] = '\0';
  if (ts == 2)
    as->s[as->length+1] = '\0';
  return (ret);
}

/*
 * libarchive 2.x made incorrect UTF-8 strings in the wrong assumption
 * that WCS is Unicode. It is true for several platforms but some are false.
 * And then people who did not use UTF-8 locale on the non Unicode WCS
 * platform and made a tar file with libarchive(mostly bsdtar) 2.x. Those
 * now cannot get right filename from libarchive 3.x and later since we
 * fixed the wrong assumption and it is incompatible to older its versions.
 * So we provide special option, "compat-2x.x", for resolving it.
 * That option enable the string conversion of libarchive 2.x.
 *
 * Translates the wrong UTF-8 string made by libarchive 2.x into current
 * locale character set and appends to the archive_string.
 * Note: returns -1 if conversion fails.
 */
static int
strncat_from_utf8_libarchive2(struct archive_string *as,
    const void *_p, size_t len, struct archive_string_conv *sc)
{
  const char *s;
  int n;
  char *p;
  char *end;
  uint32_t unicode;
#if HAVE_WCRTOMB
  mbstate_t shift_state;

  memset(&shift_state, 0, sizeof(shift_state));
#else
  /* Clear the shift state before starting. */
  wctomb(NULL, L'\0');
#endif
  (void)sc; /* UNUSED */
  /*
   * Allocate buffer for MBS.
   * We need this allocation here since it is possible that
   * as->s is still NULL.
   */
  if (archive_string_ensure(as, as->length + len + 1) == NULL)
    return (-1);

  s = (const char *)_p;
  p = as->s + as->length;
  end = as->s + as->buffer_length - MB_CUR_MAX -1;
  while ((n = _utf8_to_unicode(&unicode, s, len)) != 0) {
    wchar_t wc;

    if (p >= end) {
      as->length = p - as->s;
      /* Re-allocate buffer for MBS. */
      if (archive_string_ensure(as,
          as->length + max(len * 2,
          (size_t)MB_CUR_MAX) + 1) == NULL)
        return (-1);
      p = as->s + as->length;
      end = as->s + as->buffer_length - MB_CUR_MAX -1;
    }

    /*
     * As libarchive 2.x, translates the UTF-8 characters into
     * wide-characters in the assumption that WCS is Unicode.
     */
    if (n < 0) {
      n *= -1;
      wc = L'?';
    } else
      wc = (wchar_t)unicode;

    s += n;
    len -= n;
    /*
     * Translates the wide-character into the current locale MBS.
     */
#if HAVE_WCRTOMB
    n = (int)wcrtomb(p, wc, &shift_state);
#else
    n = (int)wctomb(p, wc);
#endif
    if (n == -1)
      return (-1);
    p += n;
  }
  as->length = p - as->s;
  as->s[as->length] = '\0';
  return (0);
}


/*
 * Conversion functions between current locale dependent MBS and UTF-16BE.
 *   strncat_from_utf16be() : UTF-16BE --> MBS
 *   strncat_to_utf16be()   : MBS --> UTF16BE
 */

#if defined(_WIN32) && !defined(__CYGWIN__)

/*
 * Convert a UTF-16BE/LE string to current locale and copy the result.
 * Return -1 if conversion fails.
 */
static int
win_strncat_from_utf16(struct archive_string *as, const void *_p, size_t bytes,
    struct archive_string_conv *sc, int be)
{
  struct archive_string tmp;
  const char *u16;
  BOOL defchar;
  char *mbs;
  size_t mbs_size, b, ll;
  int ret = 0;

  bytes &= ~1;
  if (archive_string_ensure(as, as->length + bytes +1) == NULL)
    return (-1);

  mbs = as->s + as->length;
  mbs_size = as->buffer_length - as->length -1;

  if (sc->to_cp == CP_C_LOCALE) {
    /*
     * "C" locale special processing.
     */
    u16 = _p;
    ll = 0;
    for (b = 0; b < bytes; b += 2) {
      uint16_t val;
      if (be)
        val = archive_be16dec(u16+b);
      else
        val = archive_le16dec(u16+b);
      if (val > 255) {
        *mbs++ = '?';
        ret = -1;
      } else
        *mbs++ = (char)(val&0xff);
      ll++;
    }
    as->length += ll;
    as->s[as->length] = '\0';
    return (ret);
  }

  archive_string_init(&tmp);
  if (be) {
    if (IS_BIG_ENDIAN) {
      u16 = _p;
    } else {
      if (archive_string_ensure(&tmp, bytes+2) == NULL)
        return (-1);
      memcpy(tmp.s, _p, bytes);
      for (b = 0; b < bytes; b += 2) {
        uint16_t val = archive_be16dec(tmp.s+b);
        archive_le16enc(tmp.s+b, val);
      }
      u16 = tmp.s;
    }
  } else {
    if (!IS_BIG_ENDIAN) {
      u16 = _p;
    } else {
      if (archive_string_ensure(&tmp, bytes+2) == NULL)
        return (-1);
      memcpy(tmp.s, _p, bytes);
      for (b = 0; b < bytes; b += 2) {
        uint16_t val = archive_le16dec(tmp.s+b);
        archive_be16enc(tmp.s+b, val);
      }
      u16 = tmp.s;
    }
  }

  do {
    int r;
    defchar = 0;
    /* WideCharToMultiByte is limited to int. */
    if (bytes > (size_t)INT_MAX || mbs_size > (size_t)INT_MAX)
      return (-1);
    r = WideCharToMultiByte(sc->to_cp, 0,
        (LPCWSTR)u16, (int)bytes>>1, mbs, (int)mbs_size,
      NULL, &defchar);
    /* Exit loop if we succeeded */
    if (r != 0 ||
        GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
      ll = (size_t)r;
      break;
    }
    /* Else expand buffer and loop to try again. */
    r = WideCharToMultiByte(sc->to_cp, 0,
        (LPCWSTR)u16, (int)bytes, NULL, 0, NULL, NULL);
    ll = (size_t)r;
    if (archive_string_ensure(as, ll +1) == NULL)
      return (-1);
    mbs = as->s + as->length;
    mbs_size = as->buffer_length - as->length -1;
  } while (1);
  archive_string_free(&tmp);
  as->length += ll;
  as->s[as->length] = '\0';
  if (ll == 0 || defchar)
    ret = -1;
  return (ret);
}

static int
win_strncat_from_utf16be(struct archive_string *as, const void *_p,
    size_t bytes, struct archive_string_conv *sc)
{
  return (win_strncat_from_utf16(as, _p, bytes, sc, 1));
}

static int
win_strncat_from_utf16le(struct archive_string *as, const void *_p,
    size_t bytes, struct archive_string_conv *sc)
{
  return (win_strncat_from_utf16(as, _p, bytes, sc, 0));
}

/*
 * Convert a current locale string to UTF-16BE/LE and copy the result.
 * Return -1 if conversion fails.
 */
static int
win_strncat_to_utf16(struct archive_string *as16, const void *_p,
    size_t length, struct archive_string_conv *sc, int bigendian)
{
  const char *s = (const char *)_p;
  char *u16;
  size_t count, avail;

  if (archive_string_ensure(as16,
      as16->length + (length + 1) * 2) == NULL)
    return (-1);

  u16 = as16->s + as16->length;
  avail = as16->buffer_length - 2;
  if (sc->from_cp == CP_C_LOCALE) {
    /*
     * "C" locale special processing.
     */
    count = 0;
    while (count < length && *s) {
      if (bigendian)
        archive_be16enc(u16, *s);
      else
        archive_le16enc(u16, *s);
      u16 += 2;
      s++;
      count++;
    }
    as16->length += count << 1;
    as16->s[as16->length] = 0;
    as16->s[as16->length+1] = 0;
    return (0);
  }
  do {
    int r;
    if (length > (size_t)INT_MAX || (avail >> 1) > (size_t)INT_MAX)
      return (-1);
    r = MultiByteToWideChar(sc->from_cp,
        MB_PRECOMPOSED, s, (int)length, (LPWSTR)u16, (int)avail>>1);
    /* Exit loop if we succeeded */
    if (r != 0 ||
        GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
      count = (size_t)r;
      break;
    }
    /* Expand buffer and try again */
    r = MultiByteToWideChar(sc->from_cp,
        MB_PRECOMPOSED, s, (int)length, NULL, 0);
    count = (size_t)r;
    if (archive_string_ensure(as16, (count +1) * 2)
        == NULL)
      return (-1);
    u16 = as16->s + as16->length;
    avail = as16->buffer_length - 2;
  } while (1);
  as16->length += count * 2;
  as16->s[as16->length] = 0;
  as16->s[as16->length+1] = 0;
  if (count == 0)
    return (-1);

  if (IS_BIG_ENDIAN) {
    if (!bigendian) {
      while (count > 0) {
        uint16_t v = archive_be16dec(u16);
        archive_le16enc(u16, v);
        u16 += 2;
        count--;
      }
    }
  } else {
    if (bigendian) {
      while (count > 0) {
        uint16_t v = archive_le16dec(u16);
        archive_be16enc(u16, v);
        u16 += 2;
        count--;
      }
    }
  }
  return (0);
}

static int
win_strncat_to_utf16be(struct archive_string *as16, const void *_p,
    size_t length, struct archive_string_conv *sc)
{
  return (win_strncat_to_utf16(as16, _p, length, sc, 1));
}

static int
win_strncat_to_utf16le(struct archive_string *as16, const void *_p,
    size_t length, struct archive_string_conv *sc)
{
  return (win_strncat_to_utf16(as16, _p, length, sc, 0));
}

#endif /* _WIN32 && !__CYGWIN__ */

/*
 * Do the best effort for conversions.
 * We cannot handle UTF-16BE character-set without such iconv,
 * but there is a chance if a string consists just ASCII code or
 * a current locale is UTF-8.
 */

/*
 * Convert a UTF-16BE string to current locale and copy the result.
 * Return -1 if conversion fails.
 */
static int
best_effort_strncat_from_utf16(struct archive_string *as, const void *_p,
    size_t bytes, struct archive_string_conv *sc, int be)
{
  const char *utf16 = (const char *)_p;
  char *mbs;
  uint32_t uc;
  int n, ret;

  (void)sc; /* UNUSED */
  /*
   * Other case, we should do the best effort.
   * If all character are ASCII(<0x7f), we can convert it.
   * if not , we set a alternative character and return -1.
   */
  ret = 0;
  if (archive_string_ensure(as, as->length + bytes +1) == NULL)
    return (-1);
  mbs = as->s + as->length;

  while ((n = utf16_to_unicode(&uc, utf16, bytes, be)) != 0) {
    if (n < 0) {
      n *= -1;
      ret =  -1;
    }
    bytes -= n;
    utf16 += n;

    if (uc > 127) {
      /* We cannot handle it. */
      *mbs++ = '?';
      ret =  -1;
    } else
      *mbs++ = (char)uc;
  }
  as->length = mbs - as->s;
  as->s[as->length] = '\0';
  return (ret);
}

static int
best_effort_strncat_from_utf16be(struct archive_string *as, const void *_p,
    size_t bytes, struct archive_string_conv *sc)
{
  return (best_effort_strncat_from_utf16(as, _p, bytes, sc, 1));
}

static int
best_effort_strncat_from_utf16le(struct archive_string *as, const void *_p,
    size_t bytes, struct archive_string_conv *sc)
{
  return (best_effort_strncat_from_utf16(as, _p, bytes, sc, 0));
}

/*
 * Convert a current locale string to UTF-16BE/LE and copy the result.
 * Return -1 if conversion fails.
 */
static int
best_effort_strncat_to_utf16(struct archive_string *as16, const void *_p,
    size_t length, struct archive_string_conv *sc, int bigendian)
{
  const char *s = (const char *)_p;
  char *utf16;
  size_t remaining;
  int ret;

  (void)sc; /* UNUSED */
  /*
   * Other case, we should do the best effort.
   * If all character are ASCII(<0x7f), we can convert it.
   * if not , we set a alternative character and return -1.
   */
  ret = 0;
  remaining = length;

  if (archive_string_ensure(as16,
      as16->length + (length + 1) * 2) == NULL)
    return (-1);

  utf16 = as16->s + as16->length;
  while (remaining--) {
    unsigned c = *s++;
    if (c > 127) {
      /* We cannot handle it. */
      c = UNICODE_R_CHAR;
      ret = -1;
    }
    if (bigendian)
      archive_be16enc(utf16, (uint16_t)c);
    else
      archive_le16enc(utf16, (uint16_t)c);
    utf16 += 2;
  }
  as16->length = utf16 - as16->s;
  as16->s[as16->length] = 0;
  as16->s[as16->length+1] = 0;
  return (ret);
}

static int
best_effort_strncat_to_utf16be(struct archive_string *as16, const void *_p,
    size_t length, struct archive_string_conv *sc)
{
  return (best_effort_strncat_to_utf16(as16, _p, length, sc, 1));
}

static int
best_effort_strncat_to_utf16le(struct archive_string *as16, const void *_p,
    size_t length, struct archive_string_conv *sc)
{
  return (best_effort_strncat_to_utf16(as16, _p, length, sc, 0));
}


/*
 * Multistring operations.
 */

void
archive_mstring_clean(struct archive_mstring *aes)
{
  archive_wstring_free(&(aes->aes_wcs));
  archive_string_free(&(aes->aes_mbs));
  archive_string_free(&(aes->aes_utf8));
  archive_string_free(&(aes->aes_mbs_in_locale));
  aes->aes_set = 0;
}

void
archive_mstring_copy(struct archive_mstring *dest, struct archive_mstring *src)
{
  dest->aes_set = src->aes_set;
  archive_string_copy(&(dest->aes_mbs), &(src->aes_mbs));
  archive_string_copy(&(dest->aes_utf8), &(src->aes_utf8));
  archive_wstring_copy(&(dest->aes_wcs), &(src->aes_wcs));
}

int
archive_mstring_get_utf8(struct archive *a, struct archive_mstring *aes,
  const char **p)
{
  struct archive_string_conv *sc;
  int r;

  /* If we already have a UTF8 form, return that immediately. */
  if (aes->aes_set & AES_SET_UTF8) {
    *p = aes->aes_utf8.s;
    return (0);
  }

  *p = NULL;
#if defined(_WIN32) && !defined(__CYGWIN__)
  /*
   * On Windows, first try converting from WCS because (1) there's no
   * guarantee that the conversion to MBS will succeed, e.g. when using
   * CP_ACP, and (2) that's more efficient than converting to MBS, just to
   * convert back to WCS again before finally converting to UTF-8
   */
  if ((aes->aes_set & AES_SET_WCS) != 0) {
    sc = archive_string_conversion_to_charset(a, "UTF-8", 1);
    if (sc == NULL)
      return (-1);/* Couldn't allocate memory for sc. */
    archive_string_empty(&(aes->aes_utf8));
    r = archive_string_append_from_wcs_in_codepage(&(aes->aes_utf8),
      aes->aes_wcs.s, aes->aes_wcs.length, sc);
    if (a == NULL)
      free_sconv_object(sc);
    if (r == 0) {
      aes->aes_set |= AES_SET_UTF8;
      *p = aes->aes_utf8.s;
      return (0);/* success. */
    } else
      return (-1);/* failure. */
  }
#endif
  /* Try converting WCS to MBS first if MBS does not exist yet. */
  if ((aes->aes_set & AES_SET_MBS) == 0) {
    const char *pm; /* unused */
    archive_mstring_get_mbs(a, aes, &pm); /* ignore errors, we'll handle it later */
  }
  if (aes->aes_set & AES_SET_MBS) {
    sc = archive_string_conversion_to_charset(a, "UTF-8", 1);
    if (sc == NULL)
      return (-1);/* Couldn't allocate memory for sc. */
    r = archive_strncpy_l(&(aes->aes_utf8), aes->aes_mbs.s,
        aes->aes_mbs.length, sc);
    if (a == NULL)
      free_sconv_object(sc);
    if (r == 0) {
      aes->aes_set |= AES_SET_UTF8;
      *p = aes->aes_utf8.s;
      return (0);/* success. */
    } else
      return (-1);/* failure. */
  }
  return (0);/* success. */
}

int
archive_mstring_get_mbs(struct archive *a, struct archive_mstring *aes,
    const char **p)
{
  struct archive_string_conv *sc;
  int r, ret = 0;

  /* If we already have an MBS form, return that immediately. */
  if (aes->aes_set & AES_SET_MBS) {
    *p = aes->aes_mbs.s;
    return (ret);
  }

  *p = NULL;
  /* If there's a WCS form, try converting with the native locale. */
  if (aes->aes_set & AES_SET_WCS) {
    archive_string_empty(&(aes->aes_mbs));
    r = archive_string_append_from_wcs(&(aes->aes_mbs),
        aes->aes_wcs.s, aes->aes_wcs.length);
    *p = aes->aes_mbs.s;
    if (r == 0) {
      aes->aes_set |= AES_SET_MBS;
      return (ret);
    } else
      ret = -1;
  }

  /* If there's a UTF-8 form, try converting with the native locale. */
  if (aes->aes_set & AES_SET_UTF8) {
    archive_string_empty(&(aes->aes_mbs));
    sc = archive_string_conversion_from_charset(a, "UTF-8", 1);
    if (sc == NULL)
      return (-1);/* Couldn't allocate memory for sc. */
    r = archive_strncpy_l(&(aes->aes_mbs),
      aes->aes_utf8.s, aes->aes_utf8.length, sc);
    if (a == NULL)
      free_sconv_object(sc);
    *p = aes->aes_mbs.s;
    if (r == 0) {
      aes->aes_set |= AES_SET_MBS;
      ret = 0;/* success; overwrite previous error. */
    } else
      ret = -1;/* failure. */
  }
  return (ret);
}

int
archive_mstring_get_wcs(struct archive *a, struct archive_mstring *aes,
    const wchar_t **wp)
{
  int r, ret = 0;

  (void)a;/* UNUSED */
  /* Return WCS form if we already have it. */
  if (aes->aes_set & AES_SET_WCS) {
    *wp = aes->aes_wcs.s;
    return (ret);
  }

  *wp = NULL;
#if defined(_WIN32) && !defined(__CYGWIN__)
  /*
   * On Windows, prefer converting from UTF-8 directly to WCS because:
   * (1) there's no guarantee that the string can be represented in MBS (e.g.
   * with CP_ACP), and (2) in order to convert from UTF-8 to MBS, we're going
   * to need to convert from UTF-8 to WCS anyway and its wasteful to throw
   * away that intermediate result
   */
  if (aes->aes_set & AES_SET_UTF8) {
    struct archive_string_conv *sc;

    sc = archive_string_conversion_from_charset(a, "UTF-8", 1);
    if (sc != NULL) {
      archive_wstring_empty((&aes->aes_wcs));
      r = archive_wstring_append_from_mbs_in_codepage(&(aes->aes_wcs),
          aes->aes_utf8.s, aes->aes_utf8.length, sc);
      if (a == NULL)
        free_sconv_object(sc);
      if (r == 0) {
        aes->aes_set |= AES_SET_WCS;
        *wp = aes->aes_wcs.s;
        return (0);
      }
    }
  }
#endif
  /* Try converting UTF8 to MBS first if MBS does not exist yet. */
  if ((aes->aes_set & AES_SET_MBS) == 0) {
    const char *p; /* unused */
    archive_mstring_get_mbs(a, aes, &p); /* ignore errors, we'll handle it later */
  }
  /* Try converting MBS to WCS using native locale. */
  if (aes->aes_set & AES_SET_MBS) {
    archive_wstring_empty(&(aes->aes_wcs));
    r = archive_wstring_append_from_mbs(&(aes->aes_wcs),
        aes->aes_mbs.s, aes->aes_mbs.length);
    if (r == 0) {
      aes->aes_set |= AES_SET_WCS;
      *wp = aes->aes_wcs.s;
    } else
      ret = -1;/* failure. */
  }
  return (ret);
}

int
archive_mstring_get_mbs_l(struct archive *a, struct archive_mstring *aes,
    const char **p, size_t *length, struct archive_string_conv *sc)
{
  int ret = 0;
#if defined(_WIN32) && !defined(__CYGWIN__)
  int r;

  /*
   * Internationalization programming on Windows must use Wide
   * characters because Windows platform cannot make locale UTF-8.
   */
  if (sc != NULL && (aes->aes_set & AES_SET_WCS) != 0) {
    archive_string_empty(&(aes->aes_mbs_in_locale));
    r = archive_string_append_from_wcs_in_codepage(
        &(aes->aes_mbs_in_locale), aes->aes_wcs.s,
        aes->aes_wcs.length, sc);
    if (r == 0) {
      *p = aes->aes_mbs_in_locale.s;
      if (length != NULL)
        *length = aes->aes_mbs_in_locale.length;
      return (0);
    } else if (errno == ENOMEM)
      return (-1);
    else
      ret = -1;
  }
#endif

  /* If there is not an MBS form but there is a WCS or UTF8 form, try converting
   * with the native locale to be used for translating it to specified
   * character-set. */
  if ((aes->aes_set & AES_SET_MBS) == 0) {
    const char *pm; /* unused */
    if (archive_mstring_get_mbs(a, aes, &pm) != 0) {
      /* We have another form, but failed to convert it to
       * the native locale.  Transitively, we've failed to
       * convert it to the specified character set. */
      ret = -1;
    }
  }
  /* If we already have an MBS form, use it to be translated to
   * specified character-set. */
  if (aes->aes_set & AES_SET_MBS) {
    if (sc == NULL) {
      /* Conversion is unneeded. */
      *p = aes->aes_mbs.s;
      if (length != NULL)
        *length = aes->aes_mbs.length;
      return (0);
    }
    ret = archive_strncpy_l(&(aes->aes_mbs_in_locale),
        aes->aes_mbs.s, aes->aes_mbs.length, sc);
    *p = aes->aes_mbs_in_locale.s;
    if (length != NULL)
      *length = aes->aes_mbs_in_locale.length;
  } else {
    /* Either we have no string in any form,
     * or conversion failed and set 'ret != 0'.  */
    *p = NULL;
    if (length != NULL)
      *length = 0;
  }
  return (ret);
}

int
archive_mstring_copy_mbs(struct archive_mstring *aes, const char *mbs)
{
  if (mbs == NULL) {
    aes->aes_set = 0;
    return (0);
  }
  return (archive_mstring_copy_mbs_len(aes, mbs, strlen(mbs)));
}

int
archive_mstring_copy_mbs_len(struct archive_mstring *aes, const char *mbs,
    size_t len)
{
  if (mbs == NULL) {
    aes->aes_set = 0;
    return (0);
  }
  aes->aes_set = AES_SET_MBS; /* Only MBS form is set now. */
  archive_strncpy(&(aes->aes_mbs), mbs, len);
  archive_string_empty(&(aes->aes_utf8));
  archive_wstring_empty(&(aes->aes_wcs));
  return (0);
}

int
archive_mstring_copy_wcs(struct archive_mstring *aes, const wchar_t *wcs)
{
  return archive_mstring_copy_wcs_len(aes, wcs,
        wcs == NULL ? 0 : wcslen(wcs));
}

int
archive_mstring_copy_utf8(struct archive_mstring *aes, const char *utf8)
{
  if (utf8 == NULL) {
    aes->aes_set = 0;
    return (0);
  }
  aes->aes_set = AES_SET_UTF8;
  archive_string_empty(&(aes->aes_mbs));
  archive_string_empty(&(aes->aes_wcs));
  archive_strncpy(&(aes->aes_utf8), utf8, strlen(utf8));
  return (int)strlen(utf8);
}

int
archive_mstring_copy_wcs_len(struct archive_mstring *aes, const wchar_t *wcs,
    size_t len)
{
  if (wcs == NULL) {
    aes->aes_set = 0;
    return (0);
  }
  aes->aes_set = AES_SET_WCS; /* Only WCS form set. */
  archive_string_empty(&(aes->aes_mbs));
  archive_string_empty(&(aes->aes_utf8));
  archive_wstrncpy(&(aes->aes_wcs), wcs, len);
  return (0);
}

int
archive_mstring_copy_mbs_len_l(struct archive_mstring *aes,
    const char *mbs, size_t len, struct archive_string_conv *sc)
{
  int r;

  if (mbs == NULL) {
    aes->aes_set = 0;
    return (0);
  }
  archive_string_empty(&(aes->aes_mbs));
  archive_wstring_empty(&(aes->aes_wcs));
  archive_string_empty(&(aes->aes_utf8));
#if defined(_WIN32) && !defined(__CYGWIN__)
  /*
   * Internationalization programming on Windows must use Wide
   * characters because Windows platform cannot make locale UTF-8.
   */
  if (sc == NULL) {
    if (archive_string_append(&(aes->aes_mbs),
      mbs, mbsnbytes(mbs, len)) == NULL) {
      aes->aes_set = 0;
      r = -1;
    } else {
      aes->aes_set = AES_SET_MBS;
      r = 0;
    }
#if defined(HAVE_ICONV)
  } else if (sc != NULL && sc->cd_w != (iconv_t)-1) {
    /*
     * This case happens only when MultiByteToWideChar() cannot
     * handle sc->from_cp, and we have to iconv in order to
     * translate character-set to wchar_t,UTF-16.
     */
    iconv_t cd = sc->cd;
    unsigned from_cp;
    int flag;

    /*
     * Translate multi-bytes from some character-set to UTF-8.
     */ 
    sc->cd = sc->cd_w;
    r = archive_strncpy_l(&(aes->aes_utf8), mbs, len, sc);
    sc->cd = cd;
    if (r != 0) {
      aes->aes_set = 0;
      return (r);
    }
    aes->aes_set = AES_SET_UTF8;

    /*
     * Append the UTF-8 string into wstring.
     */ 
    flag = sc->flag;
    sc->flag &= ~(SCONV_NORMALIZATION_C
        | SCONV_TO_UTF16| SCONV_FROM_UTF16);
    from_cp = sc->from_cp;
    sc->from_cp = CP_UTF8;
    r = archive_wstring_append_from_mbs_in_codepage(&(aes->aes_wcs),
      aes->aes_utf8.s, aes->aes_utf8.length, sc);
    sc->flag = flag;
    sc->from_cp = from_cp;
    if (r == 0)
      aes->aes_set |= AES_SET_WCS;
#endif
  } else {
    r = archive_wstring_append_from_mbs_in_codepage(
        &(aes->aes_wcs), mbs, len, sc);
    if (r == 0)
      aes->aes_set = AES_SET_WCS;
    else
      aes->aes_set = 0;
  }
#else
  r = archive_strncpy_l(&(aes->aes_mbs), mbs, len, sc);
  if (r == 0)
    aes->aes_set = AES_SET_MBS; /* Only MBS form is set now. */
  else
    aes->aes_set = 0;
#endif
  return (r);
}

/*
 * The 'update' form tries to proactively update all forms of
 * this string (WCS and MBS) and returns an error if any of
 * them fail.  This is used by the 'pax' handler, for instance,
 * to detect and report character-conversion failures early while
 * still allowing clients to get potentially useful values from
 * the more tolerant lazy conversions.  (get_mbs and get_wcs will
 * strive to give the user something useful, so you can get hopefully
 * usable values even if some of the character conversions are failing.)
 */
int
archive_mstring_update_utf8(struct archive *a, struct archive_mstring *aes,
    const char *utf8)
{
  struct archive_string_conv *sc;
  int r;

  if (utf8 == NULL) {
    aes->aes_set = 0;
    return (0); /* Succeeded in clearing everything. */
  }

  /* Save the UTF8 string. */
  archive_strcpy(&(aes->aes_utf8), utf8);

  /* Empty the mbs and wcs strings. */
  archive_string_empty(&(aes->aes_mbs));
  archive_wstring_empty(&(aes->aes_wcs));

  aes->aes_set = AES_SET_UTF8; /* Only UTF8 is set now. */

  sc = archive_string_conversion_from_charset(a, "UTF-8", 1);
  if (sc == NULL)
    return (-1);/* Couldn't allocate memory for sc. */

#if defined(_WIN32) && !defined(__CYGWIN__)
  /* On Windows, there's no good way to convert from UTF8 -> MBS directly, so
   * prefer to first convert to WCS as (1) it's wasteful to throw away the
   * intermediate result, and (2) WCS will still be set even if we fail to
   * convert to MBS (e.g. with ACP that can't represent the characters) */
  r = archive_wstring_append_from_mbs_in_codepage(&(aes->aes_wcs),
    aes->aes_utf8.s, aes->aes_utf8.length, sc);

  if (a == NULL)
    free_sconv_object(sc);
  if (r != 0)
    return (-1); /* This will guarantee we can't convert to MBS */
  aes->aes_set = AES_SET_UTF8 | AES_SET_WCS; /* Both UTF8 and WCS set. */

  /* Try converting WCS to MBS, return false on failure. */
  if (archive_string_append_from_wcs(&(aes->aes_mbs), aes->aes_wcs.s,
      aes->aes_wcs.length))
    return (-1);
#else
  /* Try converting UTF-8 to MBS, return false on failure. */
  r = archive_strcpy_l(&(aes->aes_mbs), utf8, sc);

  if (a == NULL)
    free_sconv_object(sc);
  if (r != 0)
    return (-1);
  aes->aes_set = AES_SET_UTF8 | AES_SET_MBS; /* Both UTF8 and MBS set. */

  /* Try converting MBS to WCS, return false on failure. */
  if (archive_wstring_append_from_mbs(&(aes->aes_wcs), aes->aes_mbs.s,
      aes->aes_mbs.length))
    return (-1);
#endif

  /* All conversions succeeded. */
  aes->aes_set = AES_SET_UTF8 | AES_SET_WCS | AES_SET_MBS;

  return (0);
}

Coverage Report

Created: 2026-04-29 07:01