newlib-cygwin/winsup/cygwin/nlsfuncs.cc

/* nlsfuncs.cc: NLS helper functions

   Copyright 2010 Red Hat, Inc.

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

#include "winsup.h"
#include <winnls.h>
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
#include <wchar.h>
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "tls_pbuf.h"
/* Internal headers from newlib */
#include "../locale/timelocal.h"
#include "../locale/lnumeric.h"
#include "../locale/lmonetary.h"
#include "../locale/lmessages.h"
#include "lc_msg.h"
#include "lc_era.h"

#define _LC(x)	&lc_##x##_ptr,lc_##x##_end-lc_##x##_ptr

#define getlocaleinfo(category,type) \
	    __getlocaleinfo(lcid,(type),_LC(category),f_wctomb,charset)
#define eval_datetimefmt(type,flags) \
	    __eval_datetimefmt(lcid,(type),(flags),&lc_time_ptr,\
			       lc_time_end-lc_time_ptr,f_wctomb, charset)

#define has_modifier(x)	((x)[0] && !strcmp (modifier, (x)))

/* Vista and later.  Not defined in w32api yet. */
extern "C" {
WINBASEAPI LCID WINAPI LocaleNameToLCID (LPCWSTR, DWORD);
};

static char last_locale[ENCODING_LEN + 1];
static LCID last_lcid;

/* Fetch LCID from POSIX locale specifier.
   Return values:

     -1: Invalid locale
      0: C or POSIX
     >0: LCID
*/
static LCID
__get_lcid_from_locale (const char *name)
{
  char locale[ENCODING_LEN + 1];
  char *c;
  LCID lcid;

  /* Speed up reusing the same locale as before, for instance in LC_ALL case. */
  if (!strcmp (name, last_locale))
    {
      debug_printf ("LCID=0x%04x", last_lcid);
      return last_lcid;
    }
  stpcpy (last_locale, name);
  stpcpy (locale, name);
  /* Store modifier for later use. */
  const char *modifier = strchr (last_locale, '@') ? : "";
  /* Drop charset and modifier */
  c = strchr (locale, '.');
  if (!c)
    c = strchr (locale, '@');
  if (c)
    *c = '\0';
  /* "POSIX" already converted to "C" in loadlocale. */
  if (!strcmp (locale, "C"))
    return last_lcid = 0;
  c = strchr (locale, '_');
  if (!c)
    return last_lcid = (LCID) -1;
  if (wincap.has_localenames ())
    {
      wchar_t wlocale[ENCODING_LEN + 1];

      /* Convert to RFC 4646 syntax which is the standard for the locale names
	 replacing LCIDs starting with Vista. */
      *c = '-';
      mbstowcs (wlocale, locale, ENCODING_LEN + 1);
      lcid = LocaleNameToLCID (wlocale, 0);
      if (lcid == 0)
	{
	  /* Unfortunately there are a couple of locales for which no form
	     without a Script part per RFC 4646 exists.
	     Linux also supports no_NO which is equivalent to nb_NO. */
	  struct {
	    const char    *loc;
	    const wchar_t *wloc;
	  } sc_only_locale[] = {
	    { "az-AZ" , L"az-Latn-AZ"  },
	    { "bs-BA" , L"bs-Latn-BA"  },
	    { "ha-NG" , L"ha-Latn-NG"  },
	    { "iu-CA" , L"iu-Latn-CA"  },
	    { "mn-CN" , L"mn-Mong-CN"  },
	    { "no-NO" , L"nb-NO"       },
	    { "sr-BA" , L"sr-Cyrl-BA"  },
	    { "sr-CS" , L"sr-Cyrl-CS"  },
	    { "sr-ME" , L"sr-Cyrl-ME"  },
	    { "sr-RS" , L"sr-Cyrl-RS"  },
	    { "tg-TJ" , L"tg-Cyrl-TJ"  },
	    { "tzm-DZ", L"tzm-Latn-DZ" },
	    { "uz-UZ" , L"uz-Latn-UZ"  },
	    { NULL    , NULL          }
	  };
	  for (int i = 0; sc_only_locale[i].loc
			  && sc_only_locale[i].loc[0] <= locale[0]; ++i)
	    if (!strcmp (locale, sc_only_locale[i].loc))
	      {
		lcid = LocaleNameToLCID (sc_only_locale[i].wloc, 0);
		if (!strncmp (locale, "sr-", 3))
		  {
		    /* Vista/2K8 is missing sr-ME and sr-RS.  It has only the
		       deprecated sr-CS.  So we map ME and RS to CS here. */
		    if (lcid == 0)
		      lcid = LocaleNameToLCID (L"sr-Cyrl-CS", 0);
		    /* "@latin" modifier for the sr_XY locales changes
			collation behaviour so lcid should accommodate that
			by being set to the Latin sublang. */
		    if (lcid != 0 && has_modifier ("@latin"))
		      lcid = MAKELANGID (lcid & 0x3ff, (lcid >> 10) - 1);
		  }
		else if (!strncmp (locale, "uz-", 3))
		  {
		    /* Equivalent for "@cyrillic" modifier in uz_UZ locale */
		    if (lcid != 0 && has_modifier ("@cyrillic"))
		      lcid = MAKELANGID (lcid & 0x3ff, (lcid >> 10) + 1);
		  }
		break;
	      }
	}
      last_lcid = lcid ?: (LCID) -1;
      debug_printf ("LCID=0x%04x", last_lcid);
      return last_lcid;
    }
  /* Pre-Vista we have to loop through the LCID values and see if they
     match language and TERRITORY. */
  *c++ = '\0';
  /* locale now points to the language, c points to the TERRITORY */
  const char *language = locale;
  const char *territory = c;
  LCID lang, sublang;
  char iso[10];

  /* In theory the lang part takes 10 bits (0x3ff), but up to Windows 2003 R2
     the highest lang value is 0x81. */
  for (lang = 1; lang <= 0x81; ++lang)
    if (GetLocaleInfo (lang, LOCALE_SISO639LANGNAME, iso, 10)
	&& !strcmp (language, iso))
      break;
  if (lang > 0x81)
    lcid = 0;
  else if (!territory)
    lcid = lang;
  else
    {
      /* In theory the sublang part takes 7 bits (0x3f), but up to
	 Windows 2003 R2 the highest sublang value is 0x14. */
      for (sublang = 1; sublang <= 0x14; ++sublang)
	{
	  lcid = (sublang << 10) | lang;
	  if (GetLocaleInfo (lcid, LOCALE_SISO3166CTRYNAME, iso, 10)
	      && !strcmp (territory, iso))
	    break;
	}
      if (sublang > 0x14)
	lcid = 0;
    }
  if (lcid == 0 && territory)
    {
      /* Unfortunately there are four language LCID number areas representing
	 multiple languages.  Fortunately only two of them already existed
	 pre-Vista.  The concealed languages have to be tested explicitly,
	 since they are not catched by the above loops.
	 This also enables the serbian ISO 3166 territory codes which have
	 been changed post 2003, and maps them to the old wrong (SP was never
	 a valid ISO 3166 code) territory code sr_SP which fortunately has the
	 same LCID as the newer sr_CS.
	 Linux also supports no_NO which is equivalent to nb_NO. */
      struct {
	const char *loc;
	LCID	    lcid;
      } ambiguous_locale[] = {
	{ "bs_BA", MAKELANGID (LANG_BOSNIAN, 0x05)			    },
        { "nn_NO", MAKELANGID (LANG_NORWEGIAN, SUBLANG_NORWEGIAN_NYNORSK)   },
        { "no_NO", MAKELANGID (LANG_NORWEGIAN, SUBLANG_NORWEGIAN_BOKMAL)    },
	{ "sr_BA", MAKELANGID (LANG_BOSNIAN,
			       SUBLANG_SERBIAN_BOSNIA_HERZEGOVINA_CYRILLIC) },
	{ "sr_CS", MAKELANGID (LANG_SERBIAN, SUBLANG_SERBIAN_CYRILLIC)      },
	{ "sr_ME", MAKELANGID (LANG_SERBIAN, SUBLANG_SERBIAN_CYRILLIC)      },
	{ "sr_RS", MAKELANGID (LANG_SERBIAN, SUBLANG_SERBIAN_CYRILLIC)      },
	{ "sr_SP", MAKELANGID (LANG_SERBIAN, SUBLANG_SERBIAN_CYRILLIC)      },
	{ NULL,    0 },
      };
      *--c = '_';
      for (int i = 0; ambiguous_locale[i].loc
		      && ambiguous_locale[i].loc[0] <= locale[0]; ++i)
	if (!strcmp (locale, ambiguous_locale[i].loc)
	    && GetLocaleInfo (ambiguous_locale[i].lcid, LOCALE_SISO639LANGNAME,
			      iso, 10))
	  {
	    lcid = ambiguous_locale[i].lcid;
	    /* "@latin" modifier for the sr_XY locales changes collation
	       behaviour so lcid should accommodate that by being set to
	       the Latin sublang. */
	    if (!strncmp (locale, "sr_", 3) && has_modifier ("@latin"))
	      lcid = MAKELANGID (lcid & 0x3ff, (lcid >> 10) - 1);
	    break;
	  }
    }
  else if (lcid == 0x0443)		/* uz_UZ (Uzbek/Uzbekistan) */
    {
      /* Equivalent for "@cyrillic" modifier in uz_UZ locale */
      if (lcid != 0 && has_modifier ("@cyrillic"))
	lcid = MAKELANGID (lcid & 0x3ff, (lcid >> 10) + 1);
    }
  last_lcid = lcid ?: (LCID) -1;
  debug_printf ("LCID=0x%04x", last_lcid);
  return last_lcid;
}

/* Never returns -1.  Just skips invalid chars instead.  Only if return_invalid
   is set, s==NULL returns -1 since then it's used to recognize invalid strings
   in the used charset. */
static size_t
lc_wcstombs (wctomb_p f_wctomb, const char *charset,
	     char *s, const wchar_t *pwcs, size_t n,
	     bool return_invalid = false)
{
  char *ptr = s;
  size_t max = n;
  char buf[8];
  size_t i, bytes, num_to_copy;
  mbstate_t state;

  memset (&state, 0, sizeof state);
  if (s == NULL)
    {
      size_t num_bytes = 0;
      while (*pwcs != 0)
	{
	  bytes = f_wctomb (_REENT, buf, *pwcs++, charset, &state);
	  if (bytes != (size_t) -1)
	    num_bytes += bytes;
	  else if (return_invalid)
	    return (size_t) -1;
	}
      return num_bytes;
    }
  while (n > 0)
    {
      bytes = f_wctomb (_REENT, buf, *pwcs, charset, &state);
      if (bytes == (size_t) -1)
	{
	  memset (&state, 0, sizeof state);
	  ++pwcs;
	  continue;
	}
      num_to_copy = (n > bytes ? bytes : n);
      for (i = 0; i < num_to_copy; ++i)
	*ptr++ = buf[i];

      if (*pwcs == 0x00)
	return ptr - s - (n >= bytes);
      ++pwcs;
      n -= num_to_copy;
    }
  return max;
}

/* Never returns -1.  Invalid sequences are translated to replacement
   wide-chars. */
static size_t
lc_mbstowcs (mbtowc_p f_mbtowc, const char *charset,
	     wchar_t *pwcs, const char *s, size_t n)
{
  size_t ret = 0;
  char *t = (char *) s;
  size_t bytes;
  mbstate_t state;

  memset (&state, 0, sizeof state);
  if (!pwcs)
    n = 1;
  while (n > 0)
    {
      bytes = f_mbtowc (_REENT, pwcs, t, 6 /* fake, always enough */,
      			charset, &state);
      if (bytes == (size_t) -1)
        {
          state.__count = 0;
          bytes = 1;
	  if (pwcs)
	    *pwcs = L' ';
        }
      else if (bytes == 0)
        break;
      t += bytes;
      ++ret;
      if (pwcs)
	{
	  ++pwcs;
	  --n;
	}
    }
  return ret;
}

static int
locale_cmp (const void *a, const void *b)
{
  char **la = (char **) a;
  char **lb = (char **) b;
  return strcmp (*la, *lb);
}

static char *
__getlocaleinfo (LCID lcid, LCTYPE type, char **ptr, size_t size,
		 wctomb_p f_wctomb, const char *charset)
{
  wchar_t wbuf[80];
  size_t num;
  char *ret;

  GetLocaleInfoW (lcid, type, wbuf, 80);
  num = lc_wcstombs (f_wctomb, charset, ret = *ptr, wbuf, size);
  *ptr += num + 1;
  return ret;
}

static UINT
getlocaleint (LCID lcid, LCTYPE type)
{
  UINT val;
  return GetLocaleInfoW (lcid, type | LOCALE_RETURN_NUMBER, (PWCHAR) &val,
			 sizeof val) ? val : 0;
}

enum dt_flags {
  DT_DEFAULT	= 0x00,
  DT_AMPM	= 0x01,	/* Enforce 12 hour time format. */
  DT_ABBREV	= 0x02,	/* Enforce abbreviated month and day names. */
};

static char *
__eval_datetimefmt (LCID lcid, LCTYPE type, dt_flags flags, char **ptr,
		    size_t size, wctomb_p f_wctomb, const char *charset)
{
  wchar_t buf[80];
  wchar_t fc;
  size_t num;
  mbstate_t mb;
  size_t idx;
  const char *day_str = "edaA";
  const char *mon_str = "mmbB";
  const char *year_str = "yyyY";
  const char *hour12_str = "lI";
  const char *hour24_str = "kH";
  const char *t_str;
  char *ret = *ptr;
  char *p = *ptr;

  GetLocaleInfoW (lcid, type, buf, 80);
  memset (&mb, 0, sizeof mb);
  for (wchar_t *fmt = buf; *fmt; ++fmt)
    switch (fc = *fmt)
      {
      case L'\'':
	if (fmt[1] == L'\'')
	  *p++ = '\'';
	else
	  while (fmt[1] && *++fmt != L'\'')
	    {
	      num = f_wctomb (_REENT, p, *fmt, charset, &mb);
	      if (num == (size_t) -1)
		memset (&mb, 0, sizeof mb);
	      else
		p += num;
	    }
	break;
      case L'd':
      case L'M':
      case L'y':
	t_str = (fc == L'd' ? day_str : fc == L'M' ? mon_str : year_str);
	for (idx = 0; fmt[1] == fc; ++idx, ++fmt);
	if (idx > 3)
	  idx = 3;
	if ((flags & DT_ABBREV) && fc != L'y' && idx == 3)
	  idx = 2;
	*p++ = '%';
	*p++ = t_str[idx];
	break;
      case L'g':
	/* TODO */
	break;
      case L'h':
      case L'H':
	t_str = (fc == L'h' || (flags & DT_AMPM) ? hour12_str : hour24_str);
	idx = 0;
	if (fmt[1] == fc)
	  {
	    ++fmt;
	    idx = 1;
	  }
	*p++ = '%';
	*p++ = t_str[idx];
	break;
      case L'm':
      case L's':
      case L't':
	if (fmt[1] == fc)
	  ++fmt;
	*p++ = '%';
	*p++ = (fc == L'm' ? 'M' : fc == L's' ? 'S' : 'p');
	break;
      case L'\t':
      case L'\n':
      case L'%':
	*p++ = '%';
	*p++ = (char) fc;
	break;
      default:
	num = f_wctomb (_REENT, p, *fmt, charset, &mb);
	if (num == (size_t) -1)
	  memset (&mb, 0, sizeof mb);
	else
	  p += num;
	break;
      }
  *p++ = '\0';
  *ptr = p;
  return ret;
}

/* Convert Windows grouping format into POSIX grouping format. */
static char *
conv_grouping (LCID lcid, LCTYPE type, char **lc_ptr)
{
  char buf[10]; /* Per MSDN max size of LOCALE_SGROUPING element incl. NUL */
  bool repeat = false;
  char *ptr = *lc_ptr;
  char *ret = ptr;

  GetLocaleInfoA (lcid, type, buf, 10);
  /* Convert Windows grouping format into POSIX grouping format. */
  for (char *c = buf; *c; ++c)
    {
      if (*c < '0' || *c > '9')
      	continue;
      char val = *c - '0';
      if (!val)
      	{
	  repeat = true;
	  break;
	}
      *ptr++ = val;
    }
  if (!repeat)
    *ptr++ = CHAR_MAX;
  *ptr++ = '\0';
  *lc_ptr = ptr;
  return ret;
}

/* Called from newlib's setlocale() via __time_load_locale() if category
   is LC_TIME.  Returns LC_TIME values fetched from Windows locale data
   in the structure pointed to by _time_locale.  This is subsequently
   accessed by functions like nl_langinfo, strftime, strptime. */
extern "C" int
__set_lc_time_from_win (const char *name, struct lc_time_T *_time_locale,
			char **lc_time_buf, wctomb_p f_wctomb,
			const char *charset)
{
  LCID lcid = __get_lcid_from_locale (name);
  if (!lcid || lcid == (LCID) -1)
    return lcid;

  char *new_lc_time_buf = (char *) malloc (4096);
  const char *lc_time_end = new_lc_time_buf + 4096;

  if (!new_lc_time_buf)
    return -1;
  char *lc_time_ptr = new_lc_time_buf;

  char locale[ENCODING_LEN + 1];
  strcpy (locale, name);
  /* Removes the charset from the locale and attach the modifer to the
     language_TERRITORY part. */
  char *c = strchr (locale, '.');
  if (c)
    {
      *c = '\0';
      char *c2 = strchr (c + 1, '@');
      /* Ignore @cjknarrow modifier since it's a very personal thing between
	 Cygwin and newlib... */
      if (c2 && strcmp (c2, "@cjknarrow"))
      	memmove (c, c2, strlen (c2) + 1);
    }
  /* Now search in the alphabetically order lc_era array for the
     locale. */
  lc_era_t locale_key = { locale, NULL, NULL, NULL, NULL, NULL ,
				  NULL, NULL, NULL, NULL, NULL };
  lc_era_t *era = (lc_era_t *) bsearch ((void *) &locale_key, (void *) lc_era,
					sizeof lc_era / sizeof *lc_era,
					sizeof *lc_era, locale_cmp);

  /* mon */
  for (int i = 0; i < 12; ++i)
    _time_locale->mon[i] = getlocaleinfo (time, LOCALE_SABBREVMONTHNAME1 + i);
  /* month and alt_month */
  for (int i = 0; i < 12; ++i)
    _time_locale->month[i] = _time_locale->alt_month[i]
			   = getlocaleinfo (time, LOCALE_SMONTHNAME1 + i);
  /* wday */
  _time_locale->wday[0] = getlocaleinfo (time, LOCALE_SABBREVDAYNAME7);
  for (int i = 0; i < 6; ++i)
    _time_locale->wday[i + 1] = getlocaleinfo (time,
					       LOCALE_SABBREVDAYNAME1 + i);
  /* weekday */
  _time_locale->weekday[0] = getlocaleinfo (time, LOCALE_SDAYNAME7);
  for (int i = 0; i < 6; ++i)
    _time_locale->weekday[i + 1] = getlocaleinfo (time, LOCALE_SDAYNAME1 + i);

  size_t len;
  /* X_fmt */
  if (era && *era->t_fmt)
    {
      _time_locale->X_fmt = (const char *) lc_time_ptr;
      len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->t_fmt,
			 lc_time_end - lc_time_ptr) + 1;
      lc_time_ptr += len;
    }
  else
    _time_locale->X_fmt = eval_datetimefmt (LOCALE_STIMEFORMAT, DT_DEFAULT);
  /* x_fmt */
  if (era && *era->d_fmt)
    {
      _time_locale->x_fmt = (const char *) lc_time_ptr;
      len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->d_fmt,
			 lc_time_end - lc_time_ptr) + 1;
      lc_time_ptr += len;
    }
  else
    _time_locale->x_fmt = eval_datetimefmt (LOCALE_SSHORTDATE, DT_DEFAULT);
  /* c_fmt */
  if (era && *era->d_t_fmt)
    {
      _time_locale->c_fmt = (const char *) lc_time_ptr;
      len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->d_t_fmt,
			 lc_time_end - lc_time_ptr) + 1;
      lc_time_ptr += len;
    }
  else
    {
      _time_locale->c_fmt = eval_datetimefmt (LOCALE_SLONGDATE, DT_ABBREV);
      --lc_time_ptr;
      *lc_time_ptr++ = ' ';
      eval_datetimefmt (LOCALE_STIMEFORMAT, DT_DEFAULT);
    }
  /* AM/PM */
  _time_locale->am_pm[0] = getlocaleinfo (time, LOCALE_S1159);
  _time_locale->am_pm[1] = getlocaleinfo (time, LOCALE_S2359);
  /* date_fmt */
  if (era && *era->date_fmt)
    {
      _time_locale->date_fmt = (const char *) lc_time_ptr;
      len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->date_fmt,
			 lc_time_end - lc_time_ptr) + 1;
      lc_time_ptr += len;
    }
  else
    {
      _time_locale->date_fmt = eval_datetimefmt (LOCALE_SLONGDATE, DT_ABBREV);
      --lc_time_ptr;
      *lc_time_ptr++ = ' ';
      eval_datetimefmt (LOCALE_STIMEFORMAT, DT_DEFAULT);
      --lc_time_ptr;
      lc_time_ptr = stpcpy (lc_time_ptr, " %Z") + 1;
    }
  /* md */
  {
    wchar_t buf[80];
    GetLocaleInfoW (lcid, LOCALE_IDATE, buf, 80);
    lc_time_ptr = stpcpy (lc_time_ptr, *buf == L'1' ? "dm" : "md") + 1;
  }
  /* ampm_fmt */
  if (era)
    {
      _time_locale->ampm_fmt = (const char *) lc_time_ptr;
      len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->t_fmt_ampm,
			 lc_time_end - lc_time_ptr) + 1;
      lc_time_ptr += len;
    }
  else
    _time_locale->ampm_fmt = eval_datetimefmt (LOCALE_STIMEFORMAT, DT_AMPM);

  if (era)
    {
      /* Evaluate string length in target charset.  Characters invalid in the
	 target charset are simply ignored, as on Linux. */
      len = 0;
      len += lc_wcstombs (f_wctomb, charset, NULL, era->era, 0) + 1;
      len += lc_wcstombs (f_wctomb, charset, NULL, era->era_d_fmt, 0) + 1;
      len += lc_wcstombs (f_wctomb, charset, NULL, era->era_d_t_fmt, 0) + 1;
      len += lc_wcstombs (f_wctomb, charset, NULL, era->era_t_fmt, 0) + 1;
      len += lc_wcstombs (f_wctomb, charset, NULL, era->alt_digits, 0) + 1;

      /* Make sure data fits into the buffer */
      if (lc_time_ptr + len > lc_time_end)
	{
	  len = lc_time_ptr + len - new_lc_time_buf;
	  char *tmp = (char *) realloc (new_lc_time_buf, len);
	  if (!tmp)
	    era = NULL;
	  else
	    {
	      lc_time_ptr = tmp + (lc_time_ptr - new_lc_time_buf);
	      new_lc_time_buf = tmp;
	      lc_time_end = new_lc_time_buf + len;
	    }
	}
      /* Copy over */
      if (era)
	{
	  /* era */
	  _time_locale->era = (const char *) lc_time_ptr;
	  len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->era,
			     lc_time_end - lc_time_ptr) + 1;
	  /* era_d_fmt */
	  _time_locale->era_d_fmt = (const char *) (lc_time_ptr += len);
	  len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->era_d_fmt,
			     lc_time_end - lc_time_ptr) + 1;
	  /* era_d_t_fmt */
	  _time_locale->era_d_t_fmt = (const char *) (lc_time_ptr += len);
	  len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->era_d_t_fmt,
			     lc_time_end - lc_time_ptr) + 1;
	  /* era_t_fmt */
	  _time_locale->era_t_fmt = (const char *) (lc_time_ptr += len);
	  len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->era_t_fmt,
			     lc_time_end - lc_time_ptr) + 1;
	  /* alt_digits */
	  _time_locale->alt_digits = (const char *) (lc_time_ptr += len);
	  len = lc_wcstombs (f_wctomb, charset, lc_time_ptr, era->alt_digits,
			     lc_time_end - lc_time_ptr) + 1;
	  lc_time_ptr += len;
	}
    }
  if (!era)
    {
      _time_locale->era =
      _time_locale->era_d_fmt = 
      _time_locale->era_d_t_fmt =
      _time_locale->era_t_fmt =
      _time_locale->alt_digits = (const char *) lc_time_ptr;
      /* Twice, to make sure era and alt_strings are correctly terminated
         with two NULs */
      *lc_time_ptr++ = '\0';
    }

  char *tmp = (char *) realloc (new_lc_time_buf, lc_time_ptr - new_lc_time_buf);
  if (!tmp)
    {
      free (new_lc_time_buf);
      return -1;
    }
  if (*lc_time_buf)
    free (*lc_time_buf);
  *lc_time_buf = tmp;
  return 1;
}

/* Called from newlib's setlocale() via __numeric_load_locale() if category
   is LC_NUMERIC.  Returns LC_NUMERIC values fetched from Windows locale data
   in the structure pointed to by _numeric_locale.  This is subsequently
   accessed by functions like nl_langinfo, localeconv, printf, etc. */
extern "C" int
__set_lc_numeric_from_win (const char *name,
			   struct lc_numeric_T *_numeric_locale,
			   char **lc_numeric_buf, wctomb_p f_wctomb,
			   const char *charset)
{
  LCID lcid = __get_lcid_from_locale (name);
  if (!lcid || lcid == (LCID) -1)
    return lcid;

  char *new_lc_numeric_buf = (char *) malloc (48);
  const char *lc_numeric_end = new_lc_numeric_buf + 48;

  if (!new_lc_numeric_buf)
    return -1;
  char *lc_numeric_ptr = new_lc_numeric_buf;
  /* decimal_point */
  _numeric_locale->decimal_point = getlocaleinfo (numeric,
						  LOCALE_SDECIMAL);
  /* thousands_sep */
  _numeric_locale->thousands_sep = getlocaleinfo (numeric,
						  LOCALE_STHOUSAND);
  /* grouping */
  _numeric_locale->grouping = conv_grouping (lcid, LOCALE_SGROUPING,
					     &lc_numeric_ptr);

  char *tmp = (char *) realloc (new_lc_numeric_buf,
  				lc_numeric_ptr - new_lc_numeric_buf);
  if (!tmp)
    {
      free (new_lc_numeric_buf);
      return -1;
    }
  if (*lc_numeric_buf)
    free (*lc_numeric_buf);
  *lc_numeric_buf = tmp;
  return 1;
}

/* Called from newlib's setlocale() via __monetary_load_locale() if category
   is LC_MONETARY.  Returns LC_MONETARY values fetched from Windows locale data
   in the structure pointed to by _monetary_locale.  This is subsequently
   accessed by functions like nl_langinfo, localeconv, printf, etc. */
extern "C" int
__set_lc_monetary_from_win (const char *name,
			    struct lc_monetary_T *_monetary_locale,
			    char **lc_monetary_buf, wctomb_p f_wctomb,
			    const char *charset)
{
  LCID lcid = __get_lcid_from_locale (name);
  if (!lcid || lcid == (LCID) -1)
    return lcid;

  char *new_lc_monetary_buf = (char *) malloc (256);
  const char *lc_monetary_end = new_lc_monetary_buf + 256;

  if (!new_lc_monetary_buf)
    return -1;
  char *lc_monetary_ptr = new_lc_monetary_buf;
  /* int_curr_symbol */
  _monetary_locale->int_curr_symbol = getlocaleinfo (monetary,
						     LOCALE_SINTLSYMBOL);
  /* No spacing char means space. */
  if (!_monetary_locale->int_curr_symbol[3])
    {
      lc_monetary_ptr[-1] = ' ';
      *lc_monetary_ptr++ = '\0';
    }
  /* currency_symbol */
  {
    /* As on Linux:  If the currency_symbol can't be represented in the
       given charset, use int_curr_symbol. */
    wchar_t wbuf[14];
    GetLocaleInfoW (lcid, LOCALE_SCURRENCY, wbuf, 14);
    if (lc_wcstombs (f_wctomb, charset, NULL, wbuf, 0, true) == (size_t) -1)
      {
	_monetary_locale->currency_symbol = lc_monetary_ptr;
	lc_monetary_ptr = stpncpy (lc_monetary_ptr,
				   _monetary_locale->int_curr_symbol, 3);
	*lc_monetary_ptr++ = '\0';
      }
    else
      _monetary_locale->currency_symbol = getlocaleinfo (monetary,
							 LOCALE_SCURRENCY);
  }
  /* mon_decimal_point */
  _monetary_locale->mon_decimal_point = getlocaleinfo (monetary,
						       LOCALE_SMONDECIMALSEP);
  /* mon_thousands_sep */
  _monetary_locale->mon_thousands_sep = getlocaleinfo (monetary,
						       LOCALE_SMONTHOUSANDSEP);
  /* mon_grouping */
  _monetary_locale->mon_grouping = conv_grouping (lcid, LOCALE_SMONGROUPING,
						  &lc_monetary_ptr);
  /* positive_sign */
  _monetary_locale->positive_sign = getlocaleinfo (monetary,
						   LOCALE_SPOSITIVESIGN);
  /* negative_sign */
  _monetary_locale->negative_sign = getlocaleinfo (monetary,
						   LOCALE_SNEGATIVESIGN);
  /* int_frac_digits */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_IINTLCURRDIGITS);
  _monetary_locale->int_frac_digits = lc_monetary_ptr++;
  /* frac_digits */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_ICURRDIGITS);
  _monetary_locale->frac_digits = lc_monetary_ptr++;
  /* p_cs_precedes */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_IPOSSYMPRECEDES);
  _monetary_locale->p_cs_precedes = lc_monetary_ptr++;
  /* p_sep_by_space */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_IPOSSEPBYSPACE);
  _monetary_locale->p_sep_by_space = lc_monetary_ptr++;
  /* n_cs_precedes */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_INEGSYMPRECEDES);
  _monetary_locale->n_cs_precedes = lc_monetary_ptr++;
  /* n_sep_by_space */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_INEGSEPBYSPACE);
  _monetary_locale->n_sep_by_space = lc_monetary_ptr++;
  /* p_sign_posn */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_IPOSSIGNPOSN);
  _monetary_locale->p_sign_posn = lc_monetary_ptr++;
  /* p_sign_posn */
  *lc_monetary_ptr = (char) getlocaleint (lcid, LOCALE_INEGSIGNPOSN);
  _monetary_locale->n_sign_posn = lc_monetary_ptr++;

  char *tmp = (char *) realloc (new_lc_monetary_buf,
  				lc_monetary_ptr - new_lc_monetary_buf);
  if (!tmp)
    {
      free (new_lc_monetary_buf);
      return -1;
    }
  if (*lc_monetary_buf)
    free (*lc_monetary_buf);
  *lc_monetary_buf = tmp;
  return 1;
}

extern "C" int
__set_lc_messages_from_win (const char *name,
			    struct lc_messages_T *_messages_locale,
			    char **lc_messages_buf,
			    wctomb_p f_wctomb, const char *charset)
{
  LCID lcid = __get_lcid_from_locale (name);
  if (!lcid || lcid == (LCID) -1)
    return lcid;

  char locale[ENCODING_LEN + 1];
  char *c, *c2;

  strcpy (locale, name);
  /* Removes the charset from the locale and attach the modifer to the
     language_TERRITORY part. */
  c = strchr (locale, '.');
  if (c)
    {
      *c = '\0';
      c2 = strchr (c + 1, '@');
      /* Ignore @cjknarrow modifier since it's a very personal thing between
	 Cygwin and newlib... */
      if (c2 && strcmp (c2, "@cjknarrow"))
      	memmove (c, c2, strlen (c2) + 1);
    }
  /* Now search in the alphabetically order lc_msg array for the
     locale. */
  lc_msg_t locale_key = { locale, NULL, NULL, NULL, NULL };
  lc_msg_t *msg = (lc_msg_t *) bsearch ((void *) &locale_key, (void *) lc_msg,
					sizeof lc_msg / sizeof *lc_msg,
					sizeof *lc_msg, locale_cmp);
  if (!msg)
    return 0;

  /* Evaluate string length in target charset.  Characters invalid in the
     target charset are simply ignored, as on Linux. */
  size_t len = 0;
  len += lc_wcstombs (f_wctomb, charset, NULL, msg->yesexpr, 0) + 1;
  len += lc_wcstombs (f_wctomb, charset, NULL, msg->noexpr, 0) + 1;
  len += lc_wcstombs (f_wctomb, charset, NULL, msg->yesstr, 0) + 1;
  len += lc_wcstombs (f_wctomb, charset, NULL, msg->nostr, 0) + 1;
  /* Allocate. */
  char *new_lc_messages_buf = (char *) malloc (len);
  const char *lc_messages_end = new_lc_messages_buf + len;

  if (!new_lc_messages_buf)
    return -1;
  /* Copy over. */
  c = new_lc_messages_buf;
  _messages_locale->yesexpr = (const char *) c;
  len = lc_wcstombs (f_wctomb, charset, c, msg->yesexpr, lc_messages_end - c);
  _messages_locale->noexpr = (const char *) (c += len + 1);
  len = lc_wcstombs (f_wctomb, charset, c, msg->noexpr, lc_messages_end - c);
  _messages_locale->yesstr = (const char *) (c += len + 1);
  len = lc_wcstombs (f_wctomb, charset, c, msg->yesstr, lc_messages_end - c);
  _messages_locale->nostr = (const char *) (c += len + 1);
  lc_wcstombs (f_wctomb, charset, c, msg->nostr, lc_messages_end - c);
  /* Aftermath. */
  if (*lc_messages_buf)
    free (*lc_messages_buf);
  *lc_messages_buf = new_lc_messages_buf;
  return 1;
}

LCID collate_lcid = 0;
static mbtowc_p collate_mbtowc = __ascii_mbtowc;
char collate_charset[ENCODING_LEN + 1] = "ASCII";

/* Called from newlib's setlocale() if category is LC_COLLATE.  Stores
   LC_COLLATE locale information.  This is subsequently accessed by the
   below functions strcoll, strxfrm, wcscoll, wcsxfrm. */
extern "C" int
__collate_load_locale (const char *name, mbtowc_p f_mbtowc, const char *charset)
{
  LCID lcid = __get_lcid_from_locale (name);
  if (lcid == (LCID) -1)
    return -1;
  collate_lcid = lcid;
  collate_mbtowc = f_mbtowc;
  stpcpy (collate_charset, charset);
  return 0;
}

/* We use the Windows functions for locale-specific string comparison and
   transformation.  The advantage is that we don't need any files with
   collation information. */
extern "C" int
wcscoll (const wchar_t *ws1, const wchar_t *ws2)
{
  int ret;

  if (!collate_lcid)
    return wcscmp (ws1, ws2);
  ret = CompareStringW (collate_lcid, 0, ws1, -1, ws2, -1);
  if (!ret)
    set_errno (EINVAL);
  return ret - CSTR_EQUAL;
}

extern "C" int
strcoll (const char *s1, const char *s2)
{
  size_t n1, n2;
  wchar_t *ws1, *ws2;
  tmp_pathbuf tp;
  int ret;

  if (!collate_lcid)
    return strcmp (s1, s2);
  /* The ANSI version of CompareString uses the default charset of the lcid,
     so we must use the Unicode version. */
  n1 = lc_mbstowcs (collate_mbtowc, collate_charset, NULL, s1, 0) + 1;
  ws1 = (n1 > NT_MAX_PATH ? (wchar_t *) malloc (n1 * sizeof (wchar_t))
			  : tp.w_get ());
  lc_mbstowcs (collate_mbtowc, collate_charset, ws1, s1, n1);
  n2 = lc_mbstowcs (collate_mbtowc, collate_charset, NULL, s2, 0) + 1;
  ws2 = (n2 > NT_MAX_PATH ? (wchar_t *) malloc (n2 * sizeof (wchar_t))
			  : tp.w_get ());
  lc_mbstowcs (collate_mbtowc, collate_charset, ws2, s2, n2);
  ret = CompareStringW (collate_lcid, 0, ws1, -1, ws2, -1);
  if (n1 > NT_MAX_PATH)
    free (ws1);
  if (n2 > NT_MAX_PATH)
    free (ws2);
  if (!ret)
    set_errno (EINVAL);
  return ret - CSTR_EQUAL;
}

extern "C" size_t
wcsxfrm (wchar_t *ws1, const wchar_t *ws2, size_t wsn)
{
  size_t ret;

  if (!collate_lcid)
    return wcslcpy (ws1, ws2, wsn);
  ret = LCMapStringW (collate_lcid, LCMAP_SORTKEY | LCMAP_BYTEREV,
		      ws2, -1, ws1, wsn * sizeof (wchar_t));
  /* LCMapStringW returns byte count including the terminating NUL character,
     wcsxfrm is supposed to return length in wchar_t excluding the NUL.
     Since the array is only single byte NUL-terminated we must make sure
     the result is wchar_t-NUL terminated. */
  if (ret)
    {
      ret = (ret + 1) / sizeof (wchar_t);
      if (ret >= wsn)
	return wsn;
      ws1[ret] = L'\0';
      return ret;
    }
  if (GetLastError () != ERROR_INSUFFICIENT_BUFFER)
    set_errno (EINVAL);
  return wsn;
}

extern "C" size_t
strxfrm (char *s1, const char *s2, size_t sn)
{
  size_t ret;
  size_t n2;
  wchar_t *ws2;
  tmp_pathbuf tp;

  if (!collate_lcid)
    return strlcpy (s1, s2, sn);
  /* The ANSI version of LCMapString uses the default charset of the lcid,
     so we must use the Unicode version. */
  n2 = lc_mbstowcs (collate_mbtowc, collate_charset, NULL, s2, 0) + 1;
  ws2 = (n2 > NT_MAX_PATH ? (wchar_t *) malloc (n2 * sizeof (wchar_t))
			  : tp.w_get ());
  lc_mbstowcs (collate_mbtowc, collate_charset, ws2, s2, n2);
  /* The sort key is a NUL-terminated byte string. */
  ret = LCMapStringW (collate_lcid, LCMAP_SORTKEY, ws2, -1, (PWCHAR) s1, sn);
  if (n2 > NT_MAX_PATH)
    free (ws2);
  if (ret == 0)
    {
      if (GetLastError () != ERROR_INSUFFICIENT_BUFFER)
	set_errno (EINVAL);
      return sn;
    }
  /* LCMapStringW returns byte count including the terminating NUL character.
     strxfrm is supposed to return length excluding the NUL. */
  return ret - 1;
}

/* Fetch default ANSI codepage from locale info and generate a setlocale
   compatible character set code.  Called from newlib's setlocale(), if the
   charset isn't given explicitely in the POSIX compatible locale specifier. */
extern "C" void
__set_charset_from_locale (const char *locale, char *charset)
{
  UINT cp;
  LCID lcid = __get_lcid_from_locale (locale);
  wchar_t wbuf[9];

  /* "C" locale, or invalid locale? */
  if (lcid == 0 || lcid == (LCID) -1)
    cp = 20127;
  else if (!GetLocaleInfoW (lcid,
			    LOCALE_IDEFAULTANSICODEPAGE | LOCALE_RETURN_NUMBER,
			    (PWCHAR) &cp, sizeof cp))
    cp = 0;
  /* Translate codepage and lcid to a charset closely aligned with the default
     charsets defined in Glibc. */
  const char *cs;
  const char *modifier = strchr (locale, '@') ?: "";
  switch (cp)
    {
    case 20127:
      cs = "ASCII";
      break;
    case 874:
      cs = "CP874";
      break;
    case 932:
      cs = "EUCJP";
      break;
    case 936:
      cs = "GB2312";
      break;
    case 949:
      cs = "EUCKR";
      break;
    case 950:
      cs = "BIG5";
      break;
    case 1250:
      if (lcid == 0x081a		/* sr_CS (Serbian Language/Former
						  Serbia and Montenegro) */
	  || lcid == 0x181a		/* sr_BA (Serbian Language/Bosnia
						  and Herzegovina) */
	  || lcid == 0x241a		/* sr_RS (Serbian Language/Serbia) */
	  || lcid == 0x2c1a		/* sr_ME (Serbian Language/Montenegro)*/
	  || lcid == 0x0442)		/* tk_TM (Turkmen/Turkmenistan) */
      	cs = "UTF-8";
      else if (lcid == 0x041c)		/* sq_AL (Albanian/Albania) */
	cs = "ISO-8859-1";
      else
	cs = "ISO-8859-2";
      break;
    case 1251:
      if (lcid == 0x0c1a		/* sr_CS (Serbian Language/Former
						  Serbia and Montenegro) */
	  || lcid == 0x1c1a		/* sr_BA (Serbian Language/Bosnia
						  and Herzegovina) */
	  || lcid == 0x281a		/* sr_RS (Serbian Language/Serbia) */
	  || lcid == 0x301a		/* sr_ME (Serbian Language/Montenegro)*/
	  || lcid == 0x0440		/* ky_KG (Kyrgyz/Kyrgyzstan) */
	  || lcid == 0x0843		/* uz_UZ (Uzbek/Uzbekistan) */
					/* tt_RU (Tatar/Russia),
						 IQTElif alphabet */
	  || (lcid == 0x0444 && has_modifier ("@iqtelif"))
	  || lcid == 0x0450)		/* mn_MN (Mongolian/Mongolia) */
      	cs = "UTF-8";
      else if (lcid == 0x0423)		/* be_BY (Belarusian/Belarus) */
	cs = has_modifier ("@latin") ? "UTF-8" : "CP1251";
      else if (lcid == 0x0402)		/* bg_BG (Bulgarian/Bulgaria) */
      	cs = "CP1251";
      else if (lcid == 0x0422)		/* uk_UA (Ukrainian/Ukraine) */
	cs = "KOI8-U";
      else
	cs = "ISO-8859-5";
      break;
    case 1252:
      if (lcid == 0x0452)		/* cy_GB (Welsh/Great Britain) */
	cs = "ISO-8859-14";
      else if (lcid == 0x4009		/* en_IN (English/India) */
	       || lcid == 0x0464	/* fil_PH (Filipino/Philippines) */
	       || lcid == 0x0462	/* fy_NL (Frisian/Netherlands) */
	       || lcid == 0x0468	/* ha_NG (Hausa/Nigeria) */
	       || lcid == 0x0470	/* ig_NG (Igbo/Nigeria) */
	       || lcid == 0x046c	/* nso_ZA (Northern Sotho/South Africa) */
	       || lcid == 0x0487	/* rw_RW (Kinyarwanda/Rwanda) */
	       || lcid == 0x043b	/* se_NO (Northern Saami/Norway) */
	       || lcid == 0x0432	/* tn_ZA (Tswana/South Africa) */
	       || lcid == 0x0488	/* wo_SN (Wolof/Senegal) */
	       || lcid == 0x046a	/* yo_NG (Yoruba/Nigeria) */
	       || lcid == 0x085d)	/* iu_CA (Inuktitut/Canada) */
      	cs = "UTF-8";
      else if (lcid == 0x042e)		/* hsb_DE (Upper Sorbian/Germany) */
	cs = "ISO-8859-2";
      else if (lcid == 0x0491		/* gd_GB (Scots Gaelic/Great Britain) */
	       || (has_modifier ("@euro")
		   && GetLocaleInfoW (lcid, LOCALE_SINTLSYMBOL, wbuf, 9)
		   && !wcsncmp (wbuf, L"EUR", 3)))
	cs = "ISO-8859-15";
      else
	cs = "ISO-8859-1";
      break;
    case 1253:
      cs = "ISO-8859-7";
      break;
    case 1254:
      if (lcid == 0x042c)		/* az_AZ (Azeri/Azerbaijan) */
      	cs = "UTF-8";
      else if (lcid == 0x0443)		/* uz_UZ (Uzbek/Uzbekistan) */
	cs = "ISO-8859-1";
      else
	cs = "ISO-8859-9";
      break;
    case 1255:
      cs = "ISO-8859-8";
      break;
    case 1256:
      if (lcid == 0x0429		/* fa_IR (Persian/Iran) */
	  || lcid == 0x0480		/* ug_CN (Uyghur/China) */
	  || lcid == 0x0420)		/* ur_PK (Urdu/Pakistan) */
	cs = "UTF-8";
      else
	cs = "ISO-8859-6";
      break;
    case 1257:
      if (lcid == 0x0425)		/* et_EE (Estonian/Estonia) */
	cs = "ISO-8859-15";
      else
	cs = "ISO-8859-13";
      break;
    case 1258:
    default:
      if (lcid == 0x0481)		/* mi_NZ (Maori/New Zealand) */
	cs = "ISO-8859-13";
      else if (lcid == 0x043a)		/* mt_MT (Maltese/Malta) */
	cs = "ISO-8859-3";
      else if (lcid == 0x0437)		/* ka_GE (Georgian/Georgia) */
	cs = "GEORGIAN-PS";
      else if (lcid == 0x043f)		/* kk_KZ (Kazakh/Kazakhstan) */
	cs = "PT154";
      else
	cs = "UTF-8";
      break;
    }
  stpcpy (charset, cs);
}

/* This function is called from newlib's loadlocale if the locale identifier
   was invalid, one way or the other.  It looks for the file

     /usr/share/locale/locale.alias

   which is part of the gettext package, and if it finds the locale alias
   in that file, it replaces the locale with the correct locale string from
   that file.
   
   If successful, it returns a pointer to new_locale, NULL otherwise.*/
extern "C" char *
__set_locale_from_locale_alias (const char *locale, char *new_locale)
{
  wchar_t wlocale[ENCODING_LEN + 1];
  wchar_t walias[ENCODING_LEN + 1];
#define LOCALE_ALIAS_LINE_LEN 255
  char alias_buf[LOCALE_ALIAS_LINE_LEN + 1], *c;
  wchar_t *wc;
  const char *alias, *replace;
  char *ret = NULL;

  FILE *fp = fopen ("/usr/share/locale/locale.alias", "rt");
  if (!fp)
    return NULL;
  /* The incoming locale is given in the application charset, or in
     the Cygwin internal charset.  We try both. */
  if (mbstowcs (wlocale, locale, ENCODING_LEN + 1) == (size_t) -1)
    sys_mbstowcs (wlocale, ENCODING_LEN + 1, locale);
  wlocale[ENCODING_LEN] = L'\0';
  /* Ignore @cjknarrow modifier since it's a very personal thing between
     Cygwin and newlib... */
  if ((wc = wcschr (wlocale, L'@')) && !wcscmp (wc + 1, L"cjknarrow"))
    *wc = L'\0';
  while (fgets (alias_buf, LOCALE_ALIAS_LINE_LEN + 1, fp))
    {
      alias_buf[LOCALE_ALIAS_LINE_LEN] = '\0';
      c = strrchr (alias_buf, '\n');
      if (c)
	*c = '\0';
      c = alias_buf;
      c += strspn (c, " \t");
      if (!*c || *c == '#')
	continue;
      alias = c;
      c += strcspn (c, " \t");
      *c++ = '\0';
      c += strspn (c, " \t");
      if (*c == '#')
	continue;
      replace = c;
      c += strcspn (c, " \t");
      *c++ = '\0';
      if (strlen (replace) > ENCODING_LEN)
	continue;
      /* The file is latin1 encoded */
      lc_mbstowcs (__iso_mbtowc, "ISO-8859-1", walias, alias, ENCODING_LEN + 1);
      walias[ENCODING_LEN] = L'\0';
      if (!wcscmp (wlocale, walias))
	{
	  ret = strcpy (new_locale, replace);
	  break;
	}
    }
  fclose (fp);
  return ret;
}

static char *
check_codepage (char *ret)
{
  if (!wincap.has_always_all_codepages ())
    {
      /* Prior to Windows Vista, many codepages are not installed by
	 default, or can be deinstalled.  The following codepages require
	 that the respective conversion tables are installed into the OS.
	 So we check if they are installed and if not, setlocale should
	 fail. */
      CPINFO cpi;
      UINT cp = 0;
      if (__mbtowc == __sjis_mbtowc)
	cp = 932;
      else if (__mbtowc == __eucjp_mbtowc)
	cp = 20932;
      else if (__mbtowc == __gbk_mbtowc)
	cp = 936;
      else if (__mbtowc == __kr_mbtowc)
	cp = 949;
      else if (__mbtowc == __big5_mbtowc)
	cp = 950;
      if (cp && !GetCPInfo (cp, &cpi)
	  && GetLastError () == ERROR_INVALID_PARAMETER)
	return NULL;
    }
  return ret;
}

/* Can be called via cygwin_internal (CW_INTERNAL_SETLOCALE) for application
   which really (think they) know what they are doing. */
extern "C" void
internal_setlocale ()
{
  /* Each setlocale from the environment potentially changes the
     multibyte representation of the CWD.  Therefore we have to
     reevaluate the CWD's posix path and store in the new charset.
     Same for the PATH environment variable. */
  /* FIXME: Other buffered paths might be affected as well. */
  /* FIXME: It could be necessary to convert the entire environment,
	    not just PATH. */
  tmp_pathbuf tp;
  char *path;
  wchar_t *w_path = NULL, *w_cwd;

  /* Don't do anything if the charset hasn't actually changed. */
  if (strcmp (cygheap->locale.charset, __locale_charset ()) == 0)
    return;

  debug_printf ("Cygwin charset changed from %s to %s",
		cygheap->locale.charset, __locale_charset ());
  /* Fetch PATH and CWD and convert to wchar_t in previous charset. */
  path = getenv ("PATH");
  if (path && *path)	/* $PATH can be potentially unset. */
    {
      w_path = tp.w_get ();
      sys_mbstowcs (w_path, 32768, path);
    }
  w_cwd = tp.w_get ();
  cwdstuff::cwd_lock.acquire ();
  sys_mbstowcs (w_cwd, 32768, cygheap->cwd.get_posix ());
  /* Set charset for internal conversion functions. */
  if (*__locale_charset () == 'A'/*SCII*/)
    {
      cygheap->locale.mbtowc = __utf8_mbtowc;
      cygheap->locale.wctomb = __utf8_wctomb;
    }
  else
    {
      cygheap->locale.mbtowc = __mbtowc;
      cygheap->locale.wctomb = __wctomb;
    }
  strcpy (cygheap->locale.charset, __locale_charset ());
  /* Restore CWD and PATH in new charset. */
  cygheap->cwd.reset_posix (w_cwd);
  cwdstuff::cwd_lock.release ();
  if (w_path)
    {
      char *c_path = tp.c_get ();
      sys_wcstombs (c_path, 32768, w_path);
      setenv ("PATH", c_path, 1);
    }
}

/* Called from dll_crt0_1, before fetching the command line from Windows.
   Set the internal charset according to the environment locale settings.
   Check if a required codepage is available, and only switch internal
   charset if so.
   Make sure to reset the application locale to "C" per POSIX. */
void
initial_setlocale ()
{
  char *ret = _setlocale_r (_REENT, LC_CTYPE, "");
  if (ret && check_codepage (ret))
    internal_setlocale ();
}

/* Like newlib's setlocale, but additionally check if the charset needs
   OS support and the required codepage is actually installed.  If codepage
   is not available, revert to previous locale and return NULL.  For details
   about codepage availability, see the comment in check_codepage() above. */
extern "C" char *
setlocale (int category, const char *locale)
{
  char old[(LC_MESSAGES + 1) * (ENCODING_LEN + 1/*"/"*/ + 1)];
  if (locale && !wincap.has_always_all_codepages ())
    stpcpy (old, _setlocale_r (_REENT, category, NULL));
  char *ret = _setlocale_r (_REENT, category, locale);
  if (ret && locale && !(ret = check_codepage (ret)))
    _setlocale_r (_REENT, category, old);
  return ret;
}