ChangeLog for libidn.

2004-03-07  Simon Josefsson  <jas@extundo.com>

	* Banner: New file.
	* Makefile: New file.
	* Version: New file.
	* configure: New file.
	* idn-stub.c: New file.
	* gunibreak.h: New file.  Copied from Libidn.
	* gunicomp.h: New file.  Copied from Libidn.
	* gunidecomp.h: New file.  Copied from Libidn.
	* idna.h: New file.  Copied from Libidn.
	* idna.c: New file.  Copied from Libidn.
	* nfkc.c: New file.  Copied from Libidn.
	* profiles.c: New file.  Copied from Libidn.
	* punycode.c: New file.  Copied from Libidn.
	* punycode.h: New file.  Copied from Libidn.
	* rfc3454.c: New file.  Copied from Libidn.
	* stringprep.c: New file.  Copied from Libidn.
	* stringprep.h: New file.  Copied from Libidn.
	* toutf8.c: New file.  Copied from Libidn.  Modified for use in glibc.

1 files changed, 1058 insertions, 0 deletions

diff --git a/libidn/nfkc.c b/libidn/nfkc.c
new file mode 100644
index 0000000..a89f49e
--- /dev/null
+++ b/libidn/nfkc.c
@@ -0,0 +1,1058 @@
+/* nfkc.c	Unicode normalization utilities.
+ * Copyright (C) 2002, 2003  Simon Josefsson
+ *
+ * This file is part of GNU Libidn.
+ *
+ * GNU Libidn is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * GNU Libidn 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GNU Libidn; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "stringprep.h"
+
+/* This file contains functions from GLIB, including gutf8.c and
+ * gunidecomp.c, all licensed under LGPL and copyright hold by:
+ *
+ *  Copyright (C) 1999, 2000 Tom Tromey
+ *  Copyright 2000 Red Hat, Inc.
+ */
+
+/* Hacks to make syncing with GLIB code easier. */
+#define gboolean int
+#define gchar char
+#define guchar unsigned char
+#define glong long
+#define gint int
+#define guint unsigned int
+#define gushort unsigned short
+#define gint16 int16_t
+#define guint16 uint16_t
+#define gunichar uint32_t
+#define gsize size_t
+#define gssize ssize_t
+#define g_malloc malloc
+#define g_free free
+#define GError void
+#define g_set_error(a,b,c,d) ((void) 0)
+#define g_new(struct_type, n_structs)					\
+  ((struct_type *) g_malloc (((gsize) sizeof (struct_type)) * ((gsize) (n_structs))))
+#  if defined (__GNUC__) && !defined (__STRICT_ANSI__) && !defined (__cplusplus)
+#    define G_STMT_START	(void)(
+#    define G_STMT_END		)
+#  else
+#    if (defined (sun) || defined (__sun__))
+#      define G_STMT_START	if (1)
+#      define G_STMT_END	else (void)0
+#    else
+#      define G_STMT_START	do
+#      define G_STMT_END	while (0)
+#    endif
+#  endif
+#define g_return_val_if_fail(expr,val)		G_STMT_START{ (void)0; }G_STMT_END
+#define G_N_ELEMENTS(arr)		(sizeof (arr) / sizeof ((arr)[0]))
+#define TRUE 1
+#define FALSE 0
+
+/* Code from GLIB gunicode.h starts here. */
+
+typedef enum
+{
+  G_NORMALIZE_DEFAULT,
+  G_NORMALIZE_NFD = G_NORMALIZE_DEFAULT,
+  G_NORMALIZE_DEFAULT_COMPOSE,
+  G_NORMALIZE_NFC = G_NORMALIZE_DEFAULT_COMPOSE,
+  G_NORMALIZE_ALL,
+  G_NORMALIZE_NFKD = G_NORMALIZE_ALL,
+  G_NORMALIZE_ALL_COMPOSE,
+  G_NORMALIZE_NFKC = G_NORMALIZE_ALL_COMPOSE
+}
+GNormalizeMode;
+
+/* Code from GLIB gutf8.c starts here. */
+
+#define UTF8_COMPUTE(Char, Mask, Len)		\
+  if (Char < 128)				\
+    {						\
+      Len = 1;					\
+      Mask = 0x7f;				\
+    }						\
+  else if ((Char & 0xe0) == 0xc0)		\
+    {						\
+      Len = 2;					\
+      Mask = 0x1f;				\
+    }						\
+  else if ((Char & 0xf0) == 0xe0)		\
+    {						\
+      Len = 3;					\
+      Mask = 0x0f;				\
+    }						\
+  else if ((Char & 0xf8) == 0xf0)		\
+    {						\
+      Len = 4;					\
+      Mask = 0x07;				\
+    }						\
+  else if ((Char & 0xfc) == 0xf8)		\
+    {						\
+      Len = 5;					\
+      Mask = 0x03;				\
+    }						\
+  else if ((Char & 0xfe) == 0xfc)		\
+    {						\
+      Len = 6;					\
+      Mask = 0x01;				\
+    }						\
+  else						\
+    Len = -1;
+
+#define UTF8_LENGTH(Char)			\
+  ((Char) < 0x80 ? 1 :				\
+   ((Char) < 0x800 ? 2 :			\
+    ((Char) < 0x10000 ? 3 :			\
+     ((Char) < 0x200000 ? 4 :			\
+      ((Char) < 0x4000000 ? 5 : 6)))))
+
+
+#define UTF8_GET(Result, Chars, Count, Mask, Len)	\
+  (Result) = (Chars)[0] & (Mask);			\
+  for ((Count) = 1; (Count) < (Len); ++(Count))		\
+    {							\
+      if (((Chars)[(Count)] & 0xc0) != 0x80)		\
+	{						\
+	  (Result) = -1;				\
+	  break;					\
+	}						\
+      (Result) <<= 6;					\
+      (Result) |= ((Chars)[(Count)] & 0x3f);		\
+    }
+
+#define UNICODE_VALID(Char)			\
+  ((Char) < 0x110000 &&				\
+   (((Char) & 0xFFFFF800) != 0xD800) &&		\
+   ((Char) < 0xFDD0 || (Char) > 0xFDEF) &&	\
+   ((Char) & 0xFFFE) != 0xFFFE)
+
+
+static const gchar utf8_skip_data[256] = {
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1,
+  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+  2, 2, 2, 2, 2, 2, 2,
+  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5,
+  5, 5, 5, 6, 6, 1, 1
+};
+
+const gchar *const g_utf8_skip = utf8_skip_data;
+
+#define g_utf8_next_char(p) (char *)((p) + g_utf8_skip[*(guchar *)(p)])
+
+/*
+ * g_utf8_strlen:
+ * @p: pointer to the start of a UTF-8 encoded string.
+ * @max: the maximum number of bytes to examine. If @max
+ *       is less than 0, then the string is assumed to be
+ *       nul-terminated. If @max is 0, @p will not be examined and
+ *       may be %NULL.
+ *
+ * Returns the length of the string in characters.
+ *
+ * Return value: the length of the string in characters
+ **/
+static glong
+g_utf8_strlen (const gchar * p, gssize max)
+{
+  glong len = 0;
+  const gchar *start = p;
+  g_return_val_if_fail (p != NULL || max == 0, 0);
+
+  if (max < 0)
+    {
+      while (*p)
+	{
+	  p = g_utf8_next_char (p);
+	  ++len;
+	}
+    }
+  else
+    {
+      if (max == 0 || !*p)
+	return 0;
+
+      p = g_utf8_next_char (p);
+
+      while (p - start < max && *p)
+	{
+	  ++len;
+	  p = g_utf8_next_char (p);
+	}
+
+      /* only do the last len increment if we got a complete
+       * char (don't count partial chars)
+       */
+      if (p - start == max)
+	++len;
+    }
+
+  return len;
+}
+
+/*
+ * g_utf8_get_char:
+ * @p: a pointer to Unicode character encoded as UTF-8
+ *
+ * Converts a sequence of bytes encoded as UTF-8 to a Unicode character.
+ * If @p does not point to a valid UTF-8 encoded character, results are
+ * undefined. If you are not sure that the bytes are complete
+ * valid Unicode characters, you should use g_utf8_get_char_validated()
+ * instead.
+ *
+ * Return value: the resulting character
+ **/
+static gunichar
+g_utf8_get_char (const gchar * p)
+{
+  int i, mask = 0, len;
+  gunichar result;
+  unsigned char c = (unsigned char) *p;
+
+  UTF8_COMPUTE (c, mask, len);
+  if (len == -1)
+    return (gunichar) - 1;
+  UTF8_GET (result, p, i, mask, len);
+
+  return result;
+}
+
+/*
+ * g_unichar_to_utf8:
+ * @c: a ISO10646 character code
+ * @outbuf: output buffer, must have at least 6 bytes of space.
+ *       If %NULL, the length will be computed and returned
+ *       and nothing will be written to @outbuf.
+ *
+ * Converts a single character to UTF-8.
+ *
+ * Return value: number of bytes written
+ **/
+static int
+g_unichar_to_utf8 (gunichar c, gchar * outbuf)
+{
+  guint len = 0;
+  int first;
+  int i;
+
+  if (c < 0x80)
+    {
+      first = 0;
+      len = 1;
+    }
+  else if (c < 0x800)
+    {
+      first = 0xc0;
+      len = 2;
+    }
+  else if (c < 0x10000)
+    {
+      first = 0xe0;
+      len = 3;
+    }
+  else if (c < 0x200000)
+    {
+      first = 0xf0;
+      len = 4;
+    }
+  else if (c < 0x4000000)
+    {
+      first = 0xf8;
+      len = 5;
+    }
+  else
+    {
+      first = 0xfc;
+      len = 6;
+    }
+
+  if (outbuf)
+    {
+      for (i = len - 1; i > 0; --i)
+	{
+	  outbuf[i] = (c & 0x3f) | 0x80;
+	  c >>= 6;
+	}
+      outbuf[0] = c | first;
+    }
+
+  return len;
+}
+
+/*
+ * g_utf8_to_ucs4_fast:
+ * @str: a UTF-8 encoded string
+ * @len: the maximum length of @str to use. If @len < 0, then
+ *       the string is nul-terminated.
+ * @items_written: location to store the number of characters in the
+ *                 result, or %NULL.
+ *
+ * Convert a string from UTF-8 to a 32-bit fixed width
+ * representation as UCS-4, assuming valid UTF-8 input.
+ * This function is roughly twice as fast as g_utf8_to_ucs4()
+ * but does no error checking on the input.
+ *
+ * Return value: a pointer to a newly allocated UCS-4 string.
+ *               This value must be freed with g_free().
+ **/
+static gunichar *
+g_utf8_to_ucs4_fast (const gchar * str, glong len, glong * items_written)
+{
+  gint j, charlen;
+  gunichar *result;
+  gint n_chars, i;
+  const gchar *p;
+
+  g_return_val_if_fail (str != NULL, NULL);
+
+  p = str;
+  n_chars = 0;
+  if (len < 0)
+    {
+      while (*p)
+	{
+	  p = g_utf8_next_char (p);
+	  ++n_chars;
+	}
+    }
+  else
+    {
+      while (p < str + len && *p)
+	{
+	  p = g_utf8_next_char (p);
+	  ++n_chars;
+	}
+    }
+
+  result = g_new (gunichar, n_chars + 1);
+  if (!result)
+    return NULL;
+
+  p = str;
+  for (i = 0; i < n_chars; i++)
+    {
+      gunichar wc = ((unsigned char *) p)[0];
+
+      if (wc < 0x80)
+	{
+	  result[i] = wc;
+	  p++;
+	}
+      else
+	{
+	  if (wc < 0xe0)
+	    {
+	      charlen = 2;
+	      wc &= 0x1f;
+	    }
+	  else if (wc < 0xf0)
+	    {
+	      charlen = 3;
+	      wc &= 0x0f;
+	    }
+	  else if (wc < 0xf8)
+	    {
+	      charlen = 4;
+	      wc &= 0x07;
+	    }
+	  else if (wc < 0xfc)
+	    {
+	      charlen = 5;
+	      wc &= 0x03;
+	    }
+	  else
+	    {
+	      charlen = 6;
+	      wc &= 0x01;
+	    }
+
+	  for (j = 1; j < charlen; j++)
+	    {
+	      wc <<= 6;
+	      wc |= ((unsigned char *) p)[j] & 0x3f;
+	    }
+
+	  result[i] = wc;
+	  p += charlen;
+	}
+    }
+  result[i] = 0;
+
+  if (items_written)
+    *items_written = i;
+
+  return result;
+}
+
+/*
+ * g_ucs4_to_utf8:
+ * @str: a UCS-4 encoded string
+ * @len: the maximum length of @str to use. If @len < 0, then
+ *       the string is terminated with a 0 character.
+ * @items_read: location to store number of characters read read, or %NULL.
+ * @items_written: location to store number of bytes written or %NULL.
+ *                 The value here stored does not include the trailing 0
+ *                 byte.
+ * @error: location to store the error occuring, or %NULL to ignore
+ *         errors. Any of the errors in #GConvertError other than
+ *         %G_CONVERT_ERROR_NO_CONVERSION may occur.
+ *
+ * Convert a string from a 32-bit fixed width representation as UCS-4.
+ * to UTF-8. The result will be terminated with a 0 byte.
+ *
+ * Return value: a pointer to a newly allocated UTF-8 string.
+ *               This value must be freed with g_free(). If an
+ *               error occurs, %NULL will be returned and
+ *               @error set.
+ **/
+static gchar *
+g_ucs4_to_utf8 (const gunichar * str,
+		glong len,
+		glong * items_read, glong * items_written, GError ** error)
+{
+  gint result_length;
+  gchar *result = NULL;
+  gchar *p;
+  gint i;
+
+  result_length = 0;
+  for (i = 0; len < 0 || i < len; i++)
+    {
+      if (!str[i])
+	break;
+
+      if (str[i] >= 0x80000000)
+	{
+	  if (items_read)
+	    *items_read = i;
+
+	  g_set_error (error, G_CONVERT_ERROR,
+		       G_CONVERT_ERROR_ILLEGAL_SEQUENCE,
+		       _("Character out of range for UTF-8"));
+	  goto err_out;
+	}
+
+      result_length += UTF8_LENGTH (str[i]);
+    }
+
+  result = g_malloc (result_length + 1);
+  if (!result)
+    return NULL;
+  p = result;
+
+  i = 0;
+  while (p < result + result_length)
+    p += g_unichar_to_utf8 (str[i++], p);
+
+  *p = '\0';
+
+  if (items_written)
+    *items_written = p - result;
+
+err_out:
+  if (items_read)
+    *items_read = i;
+
+  return result;
+}
+
+/* Code from GLIB gunidecomp.c starts here. */
+
+#include "gunidecomp.h"
+#include "gunicomp.h"
+
+#define CC_PART1(Page, Char) \
+  ((combining_class_table_part1[Page] >= G_UNICODE_MAX_TABLE_INDEX) \
+   ? (combining_class_table_part1[Page] - G_UNICODE_MAX_TABLE_INDEX) \
+   : (cclass_data[combining_class_table_part1[Page]][Char]))
+
+#define CC_PART2(Page, Char) \
+  ((combining_class_table_part2[Page] >= G_UNICODE_MAX_TABLE_INDEX) \
+   ? (combining_class_table_part2[Page] - G_UNICODE_MAX_TABLE_INDEX) \
+   : (cclass_data[combining_class_table_part2[Page]][Char]))
+
+#define COMBINING_CLASS(Char) \
+  (((Char) <= G_UNICODE_LAST_CHAR_PART1) \
+   ? CC_PART1 ((Char) >> 8, (Char) & 0xff) \
+   : (((Char) >= 0xe0000 && (Char) <= G_UNICODE_LAST_CHAR) \
+      ? CC_PART2 (((Char) - 0xe0000) >> 8, (Char) & 0xff) \
+      : 0))
+
+/* constants for hangul syllable [de]composition */
+#define SBase 0xAC00
+#define LBase 0x1100
+#define VBase 0x1161
+#define TBase 0x11A7
+#define LCount 19
+#define VCount 21
+#define TCount 28
+#define NCount (VCount * TCount)
+#define SCount (LCount * NCount)
+
+/*
+ * g_unicode_canonical_ordering:
+ * @string: a UCS-4 encoded string.
+ * @len: the maximum length of @string to use.
+ *
+ * Computes the canonical ordering of a string in-place. 
+ * This rearranges decomposed characters in the string
+ * according to their combining classes.  See the Unicode
+ * manual for more information.
+ **/
+static void
+g_unicode_canonical_ordering (gunichar * string, gsize len)
+{
+  gsize i;
+  int swap = 1;
+
+  while (swap)
+    {
+      int last;
+      swap = 0;
+      last = COMBINING_CLASS (string[0]);
+      for (i = 0; i < len - 1; ++i)
+	{
+	  int next = COMBINING_CLASS (string[i + 1]);
+	  if (next != 0 && last > next)
+	    {
+	      gsize j;
+	      /* Percolate item leftward through string.  */
+	      for (j = i + 1; j > 0; --j)
+		{
+		  gunichar t;
+		  if (COMBINING_CLASS (string[j - 1]) <= next)
+		    break;
+		  t = string[j];
+		  string[j] = string[j - 1];
+		  string[j - 1] = t;
+		  swap = 1;
+		}
+	      /* We're re-entering the loop looking at the old
+	         character again.  */
+	      next = last;
+	    }
+	  last = next;
+	}
+    }
+}
+
+/* http://www.unicode.org/unicode/reports/tr15/#Hangul
+ * r should be null or have sufficient space. Calling with r == NULL will
+ * only calculate the result_len; however, a buffer with space for three
+ * characters will always be big enough. */
+static void
+decompose_hangul (gunichar s, gunichar * r, gsize * result_len)
+{
+  gint SIndex = s - SBase;
+
+  /* not a hangul syllable */
+  if (SIndex < 0 || SIndex >= SCount)
+    {
+      if (r)
+	r[0] = s;
+      *result_len = 1;
+    }
+  else
+    {
+      gunichar L = LBase + SIndex / NCount;
+      gunichar V = VBase + (SIndex % NCount) / TCount;
+      gunichar T = TBase + SIndex % TCount;
+
+      if (r)
+	{
+	  r[0] = L;
+	  r[1] = V;
+	}
+
+      if (T != TBase)
+	{
+	  if (r)
+	    r[2] = T;
+	  *result_len = 3;
+	}
+      else
+	*result_len = 2;
+    }
+}
+
+/* returns a pointer to a null-terminated UTF-8 string */
+static const gchar *
+find_decomposition (gunichar ch, gboolean compat)
+{
+  int start = 0;
+  int end = G_N_ELEMENTS (decomp_table);
+
+  if (ch >= decomp_table[start].ch && ch <= decomp_table[end - 1].ch)
+    {
+      while (TRUE)
+	{
+	  int half = (start + end) / 2;
+	  if (ch == decomp_table[half].ch)
+	    {
+	      int offset;
+
+	      if (compat)
+		{
+		  offset = decomp_table[half].compat_offset;
+		  if (offset == G_UNICODE_NOT_PRESENT_OFFSET)
+		    offset = decomp_table[half].canon_offset;
+		}
+	      else
+		{
+		  offset = decomp_table[half].canon_offset;
+		  if (offset == G_UNICODE_NOT_PRESENT_OFFSET)
+		    return NULL;
+		}
+
+	      return &(decomp_expansion_string[offset]);
+	    }
+	  else if (half == start)
+	    break;
+	  else if (ch > decomp_table[half].ch)
+	    start = half;
+	  else
+	    end = half;
+	}
+    }
+
+  return NULL;
+}
+
+/* L,V => LV and LV,T => LVT  */
+static gboolean
+combine_hangul (gunichar a, gunichar b, gunichar * result)
+{
+  gint LIndex = a - LBase;
+  gint SIndex = a - SBase;
+
+  gint VIndex = b - VBase;
+  gint TIndex = b - TBase;
+
+  if (0 <= LIndex && LIndex < LCount && 0 <= VIndex && VIndex < VCount)
+    {
+      *result = SBase + (LIndex * VCount + VIndex) * TCount;
+      return TRUE;
+    }
+  else if (0 <= SIndex && SIndex < SCount && (SIndex % TCount) == 0
+	   && 0 <= TIndex && TIndex <= TCount)
+    {
+      *result = a + TIndex;
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+#define CI(Page, Char) \
+  ((compose_table[Page] >= G_UNICODE_MAX_TABLE_INDEX) \
+   ? (compose_table[Page] - G_UNICODE_MAX_TABLE_INDEX) \
+   : (compose_data[compose_table[Page]][Char]))
+
+#define COMPOSE_INDEX(Char) \
+     ((((Char) >> 8) > (COMPOSE_TABLE_LAST)) ? 0 : CI((Char) >> 8, (Char) & 0xff))
+
+static gboolean
+combine (gunichar a, gunichar b, gunichar * result)
+{
+  gushort index_a, index_b;
+
+  if (combine_hangul (a, b, result))
+    return TRUE;
+
+  index_a = COMPOSE_INDEX (a);
+
+  if (index_a >= COMPOSE_FIRST_SINGLE_START && index_a < COMPOSE_SECOND_START)
+    {
+      if (b == compose_first_single[index_a - COMPOSE_FIRST_SINGLE_START][0])
+	{
+	  *result =
+	    compose_first_single[index_a - COMPOSE_FIRST_SINGLE_START][1];
+	  return TRUE;
+	}
+      else
+	return FALSE;
+    }
+
+  index_b = COMPOSE_INDEX (b);
+
+  if (index_b >= COMPOSE_SECOND_SINGLE_START)
+    {
+      if (a ==
+	  compose_second_single[index_b - COMPOSE_SECOND_SINGLE_START][0])
+	{
+	  *result =
+	    compose_second_single[index_b - COMPOSE_SECOND_SINGLE_START][1];
+	  return TRUE;
+	}
+      else
+	return FALSE;
+    }
+
+  if (index_a >= COMPOSE_FIRST_START && index_a < COMPOSE_FIRST_SINGLE_START
+      && index_b >= COMPOSE_SECOND_START
+      && index_b < COMPOSE_SECOND_SINGLE_START)
+    {
+      gunichar res =
+	compose_array[index_a - COMPOSE_FIRST_START][index_b -
+						     COMPOSE_SECOND_START];
+
+      if (res)
+	{
+	  *result = res;
+	  return TRUE;
+	}
+    }
+
+  return FALSE;
+}
+
+static gunichar *
+_g_utf8_normalize_wc (const gchar * str, gssize max_len, GNormalizeMode mode)
+{
+  gsize n_wc;
+  gunichar *wc_buffer;
+  const char *p;
+  gsize last_start;
+  gboolean do_compat = (mode == G_NORMALIZE_NFKC || mode == G_NORMALIZE_NFKD);
+  gboolean do_compose = (mode == G_NORMALIZE_NFC || mode == G_NORMALIZE_NFKC);
+
+  n_wc = 0;
+  p = str;
+  while ((max_len < 0 || p < str + max_len) && *p)
+    {
+      const gchar *decomp;
+      gunichar wc = g_utf8_get_char (p);
+
+      if (wc >= 0xac00 && wc <= 0xd7af)
+	{
+	  gsize result_len;
+	  decompose_hangul (wc, NULL, &result_len);
+	  n_wc += result_len;
+	}
+      else
+	{
+	  decomp = find_decomposition (wc, do_compat);
+
+	  if (decomp)
+	    n_wc += g_utf8_strlen (decomp, -1);
+	  else
+	    n_wc++;
+	}
+
+      p = g_utf8_next_char (p);
+    }
+
+  wc_buffer = g_new (gunichar, n_wc + 1);
+  if (!wc_buffer)
+    return NULL;
+
+  last_start = 0;
+  n_wc = 0;
+  p = str;
+  while ((max_len < 0 || p < str + max_len) && *p)
+    {
+      gunichar wc = g_utf8_get_char (p);
+      const gchar *decomp;
+      int cc;
+      gsize old_n_wc = n_wc;
+
+      if (wc >= 0xac00 && wc <= 0xd7af)
+	{
+	  gsize result_len;
+	  decompose_hangul (wc, wc_buffer + n_wc, &result_len);
+	  n_wc += result_len;
+	}
+      else
+	{
+	  decomp = find_decomposition (wc, do_compat);
+
+	  if (decomp)
+	    {
+	      const char *pd;
+	      for (pd = decomp; *pd != '\0'; pd = g_utf8_next_char (pd))
+		wc_buffer[n_wc++] = g_utf8_get_char (pd);
+	    }
+	  else
+	    wc_buffer[n_wc++] = wc;
+	}
+
+      if (n_wc > 0)
+	{
+	  cc = COMBINING_CLASS (wc_buffer[old_n_wc]);
+
+	  if (cc == 0)
+	    {
+	      g_unicode_canonical_ordering (wc_buffer + last_start,
+					    n_wc - last_start);
+	      last_start = old_n_wc;
+	    }
+	}
+
+      p = g_utf8_next_char (p);
+    }
+
+  if (n_wc > 0)
+    {
+      g_unicode_canonical_ordering (wc_buffer + last_start,
+				    n_wc - last_start);
+      last_start = n_wc;
+    }
+
+  wc_buffer[n_wc] = 0;
+
+  /* All decomposed and reordered */
+
+  if (do_compose && n_wc > 0)
+    {
+      gsize i, j;
+      int last_cc = 0;
+      last_start = 0;
+
+      for (i = 0; i < n_wc; i++)
+	{
+	  int cc = COMBINING_CLASS (wc_buffer[i]);
+
+	  if (i > 0 &&
+	      (last_cc == 0 || last_cc != cc) &&
+	      combine (wc_buffer[last_start], wc_buffer[i],
+		       &wc_buffer[last_start]))
+	    {
+	      for (j = i + 1; j < n_wc; j++)
+		wc_buffer[j - 1] = wc_buffer[j];
+	      n_wc--;
+	      i--;
+
+	      if (i == last_start)
+		last_cc = 0;
+	      else
+		last_cc = COMBINING_CLASS (wc_buffer[i - 1]);
+
+	      continue;
+	    }
+
+	  if (cc == 0)
+	    last_start = i;
+
+	  last_cc = cc;
+	}
+    }
+
+  wc_buffer[n_wc] = 0;
+
+  return wc_buffer;
+}
+
+/*
+ * g_utf8_normalize:
+ * @str: a UTF-8 encoded string.
+ * @len: length of @str, in bytes, or -1 if @str is nul-terminated.
+ * @mode: the type of normalization to perform.
+ *
+ * Converts a string into canonical form, standardizing
+ * such issues as whether a character with an accent
+ * is represented as a base character and combining
+ * accent or as a single precomposed character. You
+ * should generally call g_utf8_normalize() before
+ * comparing two Unicode strings.
+ *
+ * The normalization mode %G_NORMALIZE_DEFAULT only
+ * standardizes differences that do not affect the
+ * text content, such as the above-mentioned accent
+ * representation. %G_NORMALIZE_ALL also standardizes
+ * the "compatibility" characters in Unicode, such
+ * as SUPERSCRIPT THREE to the standard forms
+ * (in this case DIGIT THREE). Formatting information
+ * may be lost but for most text operations such
+ * characters should be considered the same.
+ * For example, g_utf8_collate() normalizes
+ * with %G_NORMALIZE_ALL as its first step.
+ *
+ * %G_NORMALIZE_DEFAULT_COMPOSE and %G_NORMALIZE_ALL_COMPOSE
+ * are like %G_NORMALIZE_DEFAULT and %G_NORMALIZE_ALL,
+ * but returned a result with composed forms rather
+ * than a maximally decomposed form. This is often
+ * useful if you intend to convert the string to
+ * a legacy encoding or pass it to a system with
+ * less capable Unicode handling.
+ *
+ * Return value: a newly allocated string, that is the
+ *   normalized form of @str.
+ **/
+static gchar *
+g_utf8_normalize (const gchar * str, gssize len, GNormalizeMode mode)
+{
+  gunichar *result_wc = _g_utf8_normalize_wc (str, len, mode);
+  gchar *result;
+
+  result = g_ucs4_to_utf8 (result_wc, -1, NULL, NULL, NULL);
+  g_free (result_wc);
+
+  return result;
+}
+
+/* Public Libidn API starts here. */
+
+/**
+ * stringprep_utf8_to_unichar:
+ * @p: a pointer to Unicode character encoded as UTF-8
+ *
+ * Converts a sequence of bytes encoded as UTF-8 to a Unicode character.
+ * If @p does not point to a valid UTF-8 encoded character, results are
+ * undefined.
+ *
+ * Return value: the resulting character.
+ **/
+uint32_t
+stringprep_utf8_to_unichar (const char *p)
+{
+  return g_utf8_get_char (p);
+}
+
+/**
+ * stringprep_unichar_to_utf8:
+ * @c: a ISO10646 character code
+ * @outbuf: output buffer, must have at least 6 bytes of space.
+ *       If %NULL, the length will be computed and returned
+ *       and nothing will be written to @outbuf.
+ *
+ * Converts a single character to UTF-8.
+ *
+ * Return value: number of bytes written.
+ **/
+int
+stringprep_unichar_to_utf8 (uint32_t c, char *outbuf)
+{
+  return g_unichar_to_utf8 (c, outbuf);
+}
+
+/**
+ * stringprep_utf8_to_ucs4:
+ * @str: a UTF-8 encoded string
+ * @len: the maximum length of @str to use. If @len < 0, then
+ *       the string is nul-terminated.
+ * @items_written: location to store the number of characters in the
+ *                 result, or %NULL.
+ *
+ * Convert a string from UTF-8 to a 32-bit fixed width
+ * representation as UCS-4, assuming valid UTF-8 input.
+ * This function does no error checking on the input.
+ *
+ * Return value: a pointer to a newly allocated UCS-4 string.
+ *               This value must be freed with free().
+ **/
+uint32_t *
+stringprep_utf8_to_ucs4 (const char *str, ssize_t len, size_t * items_written)
+{
+  return g_utf8_to_ucs4_fast (str, (glong) len, (glong *) items_written);
+}
+
+/**
+ * stringprep_ucs4_to_utf8:
+ * @str: a UCS-4 encoded string
+ * @len: the maximum length of @str to use. If @len < 0, then
+ *       the string is terminated with a 0 character.
+ * @items_read: location to store number of characters read read, or %NULL.
+ * @items_written: location to store number of bytes written or %NULL.
+ *                 The value here stored does not include the trailing 0
+ *                 byte.
+ *
+ * Convert a string from a 32-bit fixed width representation as UCS-4.
+ * to UTF-8. The result will be terminated with a 0 byte.
+ *
+ * Return value: a pointer to a newly allocated UTF-8 string.
+ *               This value must be freed with free(). If an
+ *               error occurs, %NULL will be returned and
+ *               @error set.
+ **/
+char *
+stringprep_ucs4_to_utf8 (const uint32_t * str, ssize_t len,
+			 size_t * items_read, size_t * items_written)
+{
+  return g_ucs4_to_utf8 (str, len, (glong *) items_read,
+			 (glong *) items_written, NULL);
+}
+
+/**
+ * stringprep_utf8_nfkc_normalize:
+ * @str: a UTF-8 encoded string.
+ * @len: length of @str, in bytes, or -1 if @str is nul-terminated.
+ *
+ * Converts a string into canonical form, standardizing
+ * such issues as whether a character with an accent
+ * is represented as a base character and combining
+ * accent or as a single precomposed character.
+ *
+ * The normalization mode is NFKC (ALL COMPOSE).  It standardizes
+ * differences that do not affect the text content, such as the
+ * above-mentioned accent representation. It standardizes the
+ * "compatibility" characters in Unicode, such as SUPERSCRIPT THREE to
+ * the standard forms (in this case DIGIT THREE). Formatting
+ * information may be lost but for most text operations such
+ * characters should be considered the same. It returns a result with
+ * composed forms rather than a maximally decomposed form.
+ *
+ * Return value: a newly allocated string, that is the
+ *   NFKC normalized form of @str.
+ **/
+char *
+stringprep_utf8_nfkc_normalize (const char *str, ssize_t len)
+{
+  return g_utf8_normalize (str, len, G_NORMALIZE_NFKC);
+}
+
+/**
+ * stringprep_ucs4_nfkc_normalize:
+ * @str: a Unicode string.
+ * @len: length of @str array, or -1 if @str is nul-terminated.
+ *
+ * Converts UCS4 string into UTF-8 and runs
+ * stringprep_utf8_nfkc_normalize().
+ *
+ * Return value: a newly allocated Unicode string, that is the NFKC
+ *   normalized form of @str.
+ **/
+uint32_t *
+stringprep_ucs4_nfkc_normalize (uint32_t * str, ssize_t len)
+{
+  char *p;
+  uint32_t *result_wc;
+
+  p = stringprep_ucs4_to_utf8 (str, len, 0, 0);
+  result_wc = _g_utf8_normalize_wc (p, -1, G_NORMALIZE_NFKC);
+  free (p);
+
+  return result_wc;
+}