text: /* Charset conversion.
     Copyright (C) 2001-2007, 2009-2010 Free Software Foundation, Inc.
     Written by Bruno Haible and Simon Josefsson.
  
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2, or (at your option)
     any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software Foundation,
     Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  
  #include <config.h>
  
  /* Specification.  */
  #include "striconv.h"
  
  #include <errno.h>
  #include <stdlib.h>
  #include <string.h>
  
  #if HAVE_ICONV
  # include <iconv.h>
  /* Get MB_LEN_MAX, CHAR_BIT.  */
  # include <limits.h>
  #endif
  
  #include "c-strcase.h"
  
  #ifndef SIZE_MAX
  # define SIZE_MAX ((size_t) -1)
  #endif
  
  
  #if HAVE_ICONV
  
  int
  mem_cd_iconv (const char *src, size_t srclen, iconv_t cd,
                char **resultp, size_t *lengthp)
  {
  # define tmpbufsize 4096
    size_t length;
    char *result;
  
    /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug.  */
  # if defined _LIBICONV_VERSION \
       || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
    /* Set to the initial state.  */
    iconv (cd, NULL, NULL, NULL, NULL);
  # endif
  
    /* Determine the length we need.  */
    {
      size_t count = 0;
      /* The alignment is needed when converting e.g. to glibc's WCHAR_T or
         libiconv's UCS-4-INTERNAL encoding.  */
      union { unsigned int align; char buf[tmpbufsize]; } tmp;
  # define tmpbuf tmp.buf
      const char *inptr = src;
      size_t insize = srclen;
  
      while (insize > 0)
        {
          char *outptr = tmpbuf;
          size_t outsize = tmpbufsize;
          size_t res = iconv (cd,
                              (ICONV_CONST char **) &inptr, &insize,
                              &outptr, &outsize);
  
          if (res == (size_t)(-1))
            {
              if (errno == E2BIG)
                ;
              else if (errno == EINVAL)
                break;
              else
                return -1;
            }
  # if !defined _LIBICONV_VERSION && !defined __GLIBC__
          /* Irix iconv() inserts a NUL byte if it cannot convert.
             NetBSD iconv() inserts a question mark if it cannot convert.
             Only GNU libiconv and GNU libc are known to prefer to fail rather
             than doing a lossy conversion.  */
          else if (res > 0)
            {
              errno = EILSEQ;
              return -1;
            }
  # endif
          count += outptr - tmpbuf;
        }
      /* Avoid glibc-2.1 bug and Solaris 2.7 bug.  */
  # if defined _LIBICONV_VERSION \
       || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
      {
        char *outptr = tmpbuf;
        size_t outsize = tmpbufsize;
        size_t res = iconv (cd, NULL, NULL, &outptr, &outsize);
  
        if (res == (size_t)(-1))
          return -1;
        count += outptr - tmpbuf;
      }
  # endif
      length = count;
  # undef tmpbuf
    }
  
    if (length == 0)
      {
        *lengthp = 0;
        return 0;
      }
    if (*resultp != NULL && *lengthp >= length)
      result = *resultp;
    else
      {
        result = (char *) malloc (length);
        if (result == NULL)
          {
            errno = ENOMEM;
            return -1;
          }
      }
  
    /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug.  */
  # if defined _LIBICONV_VERSION \
       || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
    /* Return to the initial state.  */
    iconv (cd, NULL, NULL, NULL, NULL);
  # endif
  
    /* Do the conversion for real.  */
    {
      const char *inptr = src;
      size_t insize = srclen;
      char *outptr = result;
      size_t outsize = length;
  
      while (insize > 0)
        {
          size_t res = iconv (cd,
                              (ICONV_CONST char **) &inptr, &insize,
                              &outptr, &outsize);
  
          if (res == (size_t)(-1))
            {
              if (errno == EINVAL)
                break;
              else
                goto fail;
            }
  # if !defined _LIBICONV_VERSION && !defined __GLIBC__
          /* Irix iconv() inserts a NUL byte if it cannot convert.
             NetBSD iconv() inserts a question mark if it cannot convert.
             Only GNU libiconv and GNU libc are known to prefer to fail rather
             than doing a lossy conversion.  */
          else if (res > 0)
            {
              errno = EILSEQ;
              goto fail;
            }
  # endif
        }
      /* Avoid glibc-2.1 bug and Solaris 2.7 bug.  */
  # if defined _LIBICONV_VERSION \
       || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
      {
        size_t res = iconv (cd, NULL, NULL, &outptr, &outsize);
  
        if (res == (size_t)(-1))
          goto fail;
      }
  # endif
      if (outsize != 0)
        abort ();
    }
  
    *resultp = result;
    *lengthp = length;
  
    return 0;
  
   fail:
    {
      if (result != *resultp)
        {
          int saved_errno = errno;
          free (result);
          errno = saved_errno;
        }
      return -1;
    }
  # undef tmpbufsize
  }
  
  char *
  str_cd_iconv (const char *src, iconv_t cd)
  {
    /* For most encodings, a trailing NUL byte in the input will be converted
       to a trailing NUL byte in the output.  But not for UTF-7.  So that this
       function is usable for UTF-7, we have to exclude the NUL byte from the
       conversion and add it by hand afterwards.  */
  # if !defined _LIBICONV_VERSION && !defined __GLIBC__
    /* Irix iconv() inserts a NUL byte if it cannot convert.
       NetBSD iconv() inserts a question mark if it cannot convert.
       Only GNU libiconv and GNU libc are known to prefer to fail rather
       than doing a lossy conversion.  For other iconv() implementations,
       we have to look at the number of irreversible conversions returned;
       but this information is lost when iconv() returns for an E2BIG reason.
       Therefore we cannot use the second, faster algorithm.  */
  
    char *result = NULL;
    size_t length = 0;
    int retval = mem_cd_iconv (src, strlen (src), cd, &result, &length);
    char *final_result;
  
    if (retval < 0)
      {
        if (result != NULL)
          abort ();
        return NULL;
      }
  
    /* Add the terminating NUL byte.  */
    final_result =
      (result != NULL ? realloc (result, length + 1) : malloc (length + 1));
    if (final_result == NULL)
      {
        free (result);
        errno = ENOMEM;
        return NULL;
      }
    final_result[length] = '\0';
  
    return final_result;
  
  # else
    /* This algorithm is likely faster than the one above.  But it may produce
       iconv() returns for an E2BIG reason, when the output size guess is too
       small.  Therefore it can only be used when we don't need the number of
       irreversible conversions performed.  */
    char *result;
    size_t result_size;
    size_t length;
    const char *inptr = src;
    size_t inbytes_remaining = strlen (src);
  
    /* Make a guess for the worst-case output size, in order to avoid a
       realloc.  It's OK if the guess is wrong as long as it is not zero and
       doesn't lead to an integer overflow.  */
    result_size = inbytes_remaining;
    {
      size_t approx_sqrt_SIZE_MAX = SIZE_MAX >> (sizeof (size_t) * CHAR_BIT / 2);
      if (result_size <= approx_sqrt_SIZE_MAX / MB_LEN_MAX)
        result_size *= MB_LEN_MAX;
    }
    result_size += 1; /* for the terminating NUL */
  
    result = (char *) malloc (result_size);
    if (result == NULL)
      {
        errno = ENOMEM;
        return NULL;
      }
  
    /* Avoid glibc-2.1 bug and Solaris 2.7-2.9 bug.  */
  # if defined _LIBICONV_VERSION \
       || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
    /* Set to the initial state.  */
    iconv (cd, NULL, NULL, NULL, NULL);
  # endif
  
    /* Do the conversion.  */
    {
      char *outptr = result;
      size_t outbytes_remaining = result_size - 1;
  
      for (;;)
        {
          /* Here inptr + inbytes_remaining = src + strlen (src),
                  outptr + outbytes_remaining = result + result_size - 1.  */
          size_t res = iconv (cd,
                              (ICONV_CONST char **) &inptr, &inbytes_remaining,
                              &outptr, &outbytes_remaining);
  
          if (res == (size_t)(-1))
            {
              if (errno == EINVAL)
                break;
              else if (errno == E2BIG)
                {
                  size_t used = outptr - result;
                  size_t newsize = result_size * 2;
                  char *newresult;
  
                  if (!(newsize > result_size))
                    {
                      errno = ENOMEM;
                      goto failed;
                    }
                  newresult = (char *) realloc (result, newsize);
                  if (newresult == NULL)
                    {
                      errno = ENOMEM;
                      goto failed;
                    }
                  result = newresult;
                  result_size = newsize;
                  outptr = result + used;
                  outbytes_remaining = result_size - 1 - used;
                }
              else
                goto failed;
            }
          else
            break;
        }
      /* Avoid glibc-2.1 bug and Solaris 2.7 bug.  */
  # if defined _LIBICONV_VERSION \
       || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
      for (;;)
        {
          /* Here outptr + outbytes_remaining = result + result_size - 1.  */
          size_t res = iconv (cd, NULL, NULL, &outptr, &outbytes_remaining);
  
          if (res == (size_t)(-1))
            {
              if (errno == E2BIG)
                {
                  size_t used = outptr - result;
                  size_t newsize = result_size * 2;
                  char *newresult;
  
                  if (!(newsize > result_size))
                    {
                      errno = ENOMEM;
                      goto failed;
                    }
                  newresult = (char *) realloc (result, newsize);
                  if (newresult == NULL)
                    {
                      errno = ENOMEM;
                      goto failed;
                    }
                  result = newresult;
                  result_size = newsize;
                  outptr = result + used;
                  outbytes_remaining = result_size - 1 - used;
                }
              else
                goto failed;
            }
          else
            break;
        }
  # endif
  
      /* Add the terminating NUL byte.  */
      *outptr++ = '\0';
  
      length = outptr - result;
    }
  
    /* Give away unused memory.  */
    if (length < result_size)
      {
        char *smaller_result = (char *) realloc (result, length);
  
        if (smaller_result != NULL)
          result = smaller_result;
      }
  
    return result;
  
   failed:
    {
      int saved_errno = errno;
      free (result);
      errno = saved_errno;
      return NULL;
    }
  
  # endif
  }
  
  #endif
  
  char *
  str_iconv (const char *src, const char *from_codeset, const char *to_codeset)
  {
    if (*src == '\0' || c_strcasecmp (from_codeset, to_codeset) == 0)
      {
        char *result = strdup (src);
  
        if (result == NULL)
          errno = ENOMEM;
        return result;
      }
    else
      {
  #if HAVE_ICONV
        iconv_t cd;
        char *result;
  
        /* Avoid glibc-2.1 bug with EUC-KR.  */
  # if (__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) && !defined _LIBICONV_VERSION
        if (c_strcasecmp (from_codeset, "EUC-KR") == 0
            || c_strcasecmp (to_codeset, "EUC-KR") == 0)
          {
            errno = EINVAL;
            return NULL;
          }
  # endif
        cd = iconv_open (to_codeset, from_codeset);
        if (cd == (iconv_t) -1)
          return NULL;
  
        result = str_cd_iconv (src, cd);
  
        if (result == NULL)
          {
            /* Close cd, but preserve the errno from str_cd_iconv.  */
            int saved_errno = errno;
            iconv_close (cd);
            errno = saved_errno;
          }
        else
          {
            if (iconv_close (cd) < 0)
              {
                /* Return NULL, but free the allocated memory, and while doing
                   that, preserve the errno from iconv_close.  */
                int saved_errno = errno;
                free (result);
                errno = saved_errno;
                return NULL;
              }
          }
        return result;
  #else
        /* This is a different error code than if iconv_open existed but didn't
           support from_codeset and to_codeset, so that the caller can emit
           an error message such as
             "iconv() is not supported. Installing GNU libiconv and
              then reinstalling this package would fix this."  */
        errno = ENOSYS;
        return NULL;
  #endif
      }
  }
  