/* Copyright (c) 2000, 2023, Oracle and/or its affiliates. All rights
 * reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.

   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, version 2.0, 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 St, Fifth Floor, Boston, MA 02110-1301  USA */

#include <my_global.h>
#include <m_ctype.h>
#include <my_xml.h>
#include <m_string.h>


/*

  This files implements routines which parse XML based
  character set and collation description files.
  
  Unicode collations are encoded according to
  
    Unicode Technical Standard #35
    Locale Data Markup Language (LDML)
    http://www.unicode.org/reports/tr35/
  
  and converted into ICU string according to
  
    Collation Customization
    http://oss.software.ibm.com/icu/userguide/Collate_Customization.html
  
*/


/*
  Avoid using my_snprintf
  We cannot use my_snprintf() here, because ctype.o is
  used to build conf_to_src, which must require minimun
  dependency.
*/

#undef my_snprinf
#define my_snprintf "We cannot use my_snprintf in this file"


int (*my_string_stack_guard)(int)= NULL;

static char *mstr(char *str,const char *src,size_t l1,size_t l2)
{
  l1= l1<l2 ? l1 : l2;
  memcpy(str,src,l1);
  str[l1]='\0';
  return str;
}

struct my_cs_file_section_st
{
  int        state;
  const char *str;
};

#define _CS_MISC	1
#define _CS_ID		2
#define _CS_CSNAME	3
#define _CS_FAMILY	4
#define _CS_ORDER	5
#define _CS_COLNAME	6
#define _CS_FLAG	7
#define _CS_CHARSET	8
#define _CS_COLLATION	9
#define _CS_UPPERMAP	10
#define _CS_LOWERMAP	11
#define _CS_UNIMAP	12
#define _CS_COLLMAP	13
#define _CS_CTYPEMAP	14
#define _CS_PRIMARY_ID	15
#define _CS_BINARY_ID	16
#define _CS_CSDESCRIPT	17


/* Special purpose commands */
#define _CS_UCA_VERSION                 100
#define _CS_CL_SUPPRESS_CONTRACTIONS    101
#define _CS_CL_OPTIMIZE                 102
#define _CS_CL_SHIFT_AFTER_METHOD       103


/* Collation Settings */
#define _CS_ST_SETTINGS                 200
#define _CS_ST_STRENGTH                 201
#define _CS_ST_ALTERNATE                202
#define _CS_ST_BACKWARDS                203
#define _CS_ST_NORMALIZATION            204
#define _CS_ST_CASE_LEVEL               205
#define _CS_ST_CASE_FIRST               206
#define _CS_ST_HIRAGANA_QUATERNARY      207
#define _CS_ST_NUMERIC                  208
#define _CS_ST_VARIABLE_TOP             209
#define _CS_ST_MATCH_BOUNDARIES         210
#define _CS_ST_MATCH_STYLE              211


/* Rules */
#define _CS_RULES                       300
#define _CS_RESET                       301
#define _CS_DIFF1                       302
#define _CS_DIFF2                       303
#define _CS_DIFF3                       304
#define _CS_DIFF4                       305
#define _CS_IDENTICAL                   306

/* Rules: Expansions */
#define _CS_EXP_X                       320
#define _CS_EXP_EXTEND                  321
#define _CS_EXP_DIFF1                   322
#define _CS_EXP_DIFF2                   323
#define _CS_EXP_DIFF3                   324
#define _CS_EXP_DIFF4                   325
#define _CS_EXP_IDENTICAL               326

/* Rules: Abbreviating Ordering Specifications */
#define _CS_A_DIFF1                     351
#define _CS_A_DIFF2                     352
#define _CS_A_DIFF3                     353
#define _CS_A_DIFF4                     354
#define _CS_A_IDENTICAL                 355

/* Rules: previous context */
#define _CS_CONTEXT                     370

/* Rules: Placing Characters Before Others*/
#define _CS_RESET_BEFORE 380

/* Rules: Logical Reset Positions */
#define _CS_RESET_FIRST_PRIMARY_IGNORABLE     401
#define _CS_RESET_LAST_PRIMARY_IGNORABLE      402
#define _CS_RESET_FIRST_SECONDARY_IGNORABLE   403
#define _CS_RESET_LAST_SECONDARY_IGNORABLE    404
#define _CS_RESET_FIRST_TERTIARY_IGNORABLE    405
#define _CS_RESET_LAST_TERTIARY_IGNORABLE     406
#define _CS_RESET_FIRST_TRAILING              407
#define _CS_RESET_LAST_TRAILING               408
#define _CS_RESET_FIRST_VARIABLE              409
#define _CS_RESET_LAST_VARIABLE               410
#define _CS_RESET_FIRST_NON_IGNORABLE         411
#define _CS_RESET_LAST_NON_IGNORABLE          412



static struct my_cs_file_section_st sec[] =
{
  {_CS_MISC,		"xml"},
  {_CS_MISC,		"xml/version"},
  {_CS_MISC,		"xml/encoding"},
  {_CS_MISC,		"charsets"},
  {_CS_MISC,		"charsets/max-id"},
  {_CS_MISC,		"charsets/copyright"},
  {_CS_MISC,		"charsets/description"},
  {_CS_CHARSET,		"charsets/charset"},
  {_CS_PRIMARY_ID,	"charsets/charset/primary-id"},
  {_CS_BINARY_ID,	"charsets/charset/binary-id"},
  {_CS_CSNAME,		"charsets/charset/name"},
  {_CS_FAMILY,		"charsets/charset/family"},
  {_CS_CSDESCRIPT,	"charsets/charset/description"},
  {_CS_MISC,		"charsets/charset/alias"},
  {_CS_MISC,		"charsets/charset/ctype"},
  {_CS_CTYPEMAP,	"charsets/charset/ctype/map"},
  {_CS_MISC,		"charsets/charset/upper"},
  {_CS_UPPERMAP,	"charsets/charset/upper/map"},
  {_CS_MISC,		"charsets/charset/lower"},
  {_CS_LOWERMAP,	"charsets/charset/lower/map"},
  {_CS_MISC,		"charsets/charset/unicode"},
  {_CS_UNIMAP,		"charsets/charset/unicode/map"},
  {_CS_COLLATION,	"charsets/charset/collation"},
  {_CS_COLNAME,		"charsets/charset/collation/name"},
  {_CS_ID,		"charsets/charset/collation/id"},
  {_CS_ORDER,		"charsets/charset/collation/order"},
  {_CS_FLAG,		"charsets/charset/collation/flag"},
  {_CS_COLLMAP,		"charsets/charset/collation/map"},

  /* Special purpose commands */
  {_CS_UCA_VERSION,              "charsets/charset/collation/version"},
  {_CS_CL_SUPPRESS_CONTRACTIONS, "charsets/charset/collation/suppress_contractions"},
  {_CS_CL_OPTIMIZE,              "charsets/charset/collation/optimize"},
  {_CS_CL_SHIFT_AFTER_METHOD,    "charsets/charset/collation/shift-after-method"},

  /* Collation Settings */
  {_CS_ST_SETTINGS,              "charsets/charset/collation/settings"},
  {_CS_ST_STRENGTH,              "charsets/charset/collation/settings/strength"},
  {_CS_ST_ALTERNATE,             "charsets/charset/collation/settings/alternate"},
  {_CS_ST_BACKWARDS,             "charsets/charset/collation/settings/backwards"},
  {_CS_ST_NORMALIZATION,         "charsets/charset/collation/settings/normalization"},
  {_CS_ST_CASE_LEVEL,            "charsets/charset/collation/settings/caseLevel"},
  {_CS_ST_CASE_FIRST,            "charsets/charset/collation/settings/caseFirst"},
  {_CS_ST_HIRAGANA_QUATERNARY,   "charsets/charset/collation/settings/hiraganaQuaternary"},
  {_CS_ST_NUMERIC,               "charsets/charset/collation/settings/numeric"},
  {_CS_ST_VARIABLE_TOP,          "charsets/charset/collation/settings/variableTop"},
  {_CS_ST_MATCH_BOUNDARIES,      "charsets/charset/collation/settings/match-boundaries"},
  {_CS_ST_MATCH_STYLE,           "charsets/charset/collation/settings/match-style"},

  /* Rules */
  {_CS_RULES,           "charsets/charset/collation/rules"},
  {_CS_RESET,           "charsets/charset/collation/rules/reset"},
  {_CS_DIFF1,           "charsets/charset/collation/rules/p"},
  {_CS_DIFF2,           "charsets/charset/collation/rules/s"},
  {_CS_DIFF3,           "charsets/charset/collation/rules/t"},
  {_CS_DIFF4,           "charsets/charset/collation/rules/q"},
  {_CS_IDENTICAL,       "charsets/charset/collation/rules/i"},

  /* Rules: expansions */
  {_CS_EXP_X,           "charsets/charset/collation/rules/x"},
  {_CS_EXP_EXTEND,      "charsets/charset/collation/rules/x/extend"},
  {_CS_EXP_DIFF1,       "charsets/charset/collation/rules/x/p"},
  {_CS_EXP_DIFF2,       "charsets/charset/collation/rules/x/s"},
  {_CS_EXP_DIFF3,       "charsets/charset/collation/rules/x/t"},
  {_CS_EXP_DIFF4,       "charsets/charset/collation/rules/x/q"},
  {_CS_EXP_IDENTICAL,   "charsets/charset/collation/rules/x/i"},
  
  /* Rules: previous context */
  {_CS_CONTEXT,         "charsets/charset/collation/rules/x/context"},

  /* Rules: Abbreviating Ordering Specifications */
  {_CS_A_DIFF1,         "charsets/charset/collation/rules/pc"},
  {_CS_A_DIFF2,         "charsets/charset/collation/rules/sc"},
  {_CS_A_DIFF3,         "charsets/charset/collation/rules/tc"},
  {_CS_A_DIFF4,         "charsets/charset/collation/rules/qc"},
  {_CS_A_IDENTICAL,     "charsets/charset/collation/rules/ic"},

  /* Rules: Placing Characters Before Others*/
  {_CS_RESET_BEFORE,    "charsets/charset/collation/rules/reset/before"},

  /* Rules: Logical Reset Positions */
  {_CS_RESET_FIRST_NON_IGNORABLE,       "charsets/charset/collation/rules/reset/first_non_ignorable"},
  {_CS_RESET_LAST_NON_IGNORABLE,        "charsets/charset/collation/rules/reset/last_non_ignorable"},
  {_CS_RESET_FIRST_PRIMARY_IGNORABLE,   "charsets/charset/collation/rules/reset/first_primary_ignorable"},
  {_CS_RESET_LAST_PRIMARY_IGNORABLE,    "charsets/charset/collation/rules/reset/last_primary_ignorable"},
  {_CS_RESET_FIRST_SECONDARY_IGNORABLE, "charsets/charset/collation/rules/reset/first_secondary_ignorable"},
  {_CS_RESET_LAST_SECONDARY_IGNORABLE,  "charsets/charset/collation/rules/reset/last_secondary_ignorable"},
  {_CS_RESET_FIRST_TERTIARY_IGNORABLE,  "charsets/charset/collation/rules/reset/first_tertiary_ignorable"},
  {_CS_RESET_LAST_TERTIARY_IGNORABLE,   "charsets/charset/collation/rules/reset/last_tertiary_ignorable"},
  {_CS_RESET_FIRST_TRAILING,            "charsets/charset/collation/rules/reset/first_trailing"},
  {_CS_RESET_LAST_TRAILING,             "charsets/charset/collation/rules/reset/last_trailing"},
  {_CS_RESET_FIRST_VARIABLE,            "charsets/charset/collation/rules/reset/first_variable"},
  {_CS_RESET_LAST_VARIABLE,             "charsets/charset/collation/rules/reset/last_variable"},

  {0,	NULL}
};

static struct my_cs_file_section_st * cs_file_sec(const char *attr, size_t len)
{
  struct my_cs_file_section_st *s;
  for (s= sec; s->str; s++)
  {
    if (!strncmp(attr, s->str, len) && s->str[len] == 0)
      return s;
  }
  return NULL;
}

#define MY_CS_CSDESCR_SIZE	64
#define MY_CS_TAILORING_SIZE	32*1024
#define MY_CS_UCA_VERSION_SIZE  64
#define MY_CS_CONTEXT_SIZE      64

typedef struct my_cs_file_info
{
  char   csname[MY_CS_NAME_SIZE];
  char   name[MY_CS_NAME_SIZE];
  uchar  ctype[MY_CS_CTYPE_TABLE_SIZE];
  uchar  to_lower[MY_CS_TO_LOWER_TABLE_SIZE];
  uchar  to_upper[MY_CS_TO_UPPER_TABLE_SIZE];
  uchar  sort_order[MY_CS_SORT_ORDER_TABLE_SIZE];
  uint16 tab_to_uni[MY_CS_TO_UNI_TABLE_SIZE];
  char   comment[MY_CS_CSDESCR_SIZE];
  char  *tailoring;
  size_t tailoring_length;
  size_t tailoring_alloced_length;
  char   context[MY_CS_CONTEXT_SIZE];
  CHARSET_INFO cs;
  MY_CHARSET_LOADER *loader;
} MY_CHARSET_FILE;


static void
my_charset_file_reset_charset(MY_CHARSET_FILE *i)
{
  memset(&i->cs, 0, sizeof(i->cs));
}


static void
my_charset_file_reset_collation(MY_CHARSET_FILE *i)
{
  i->tailoring_length= 0;
  i->context[0]= '\0';
}


static void
my_charset_file_init(MY_CHARSET_FILE *i)
{
  my_charset_file_reset_charset(i);
  my_charset_file_reset_collation(i);
  i->tailoring= NULL;
  i->tailoring_alloced_length= 0;
}


static void
my_charset_file_free(MY_CHARSET_FILE *i)
{
  i->loader->mem_free(i->tailoring);
}


static int
my_charset_file_tailoring_realloc(MY_CHARSET_FILE *i, size_t newlen)
{
  if (i->tailoring_alloced_length > newlen ||
      (i->tailoring= i->loader->mem_realloc(i->tailoring,
                                       (i->tailoring_alloced_length=
                                        (newlen + 32*1024)))))
  {
    return MY_XML_OK;
  }
  return MY_XML_ERROR;
}


static int fill_uchar(uchar *a,uint size,const char *str, size_t len)
{
  uint i= 0;
  const char *s, *b, *e=str+len;
  
  for (s=str ; s < e ; i++)
  { 
    for ( ; (s < e) && strchr(" \t\r\n",s[0]); s++) ;
    b=s;
    for ( ; (s < e) && !strchr(" \t\r\n",s[0]); s++) ;
    if (s == b || i > size)
      break;
    a[i]= (uchar) strtoul(b,NULL,16);
  }
  return 0;
}

static int fill_uint16(uint16 *a,uint size,const char *str, size_t len)
{
  uint i= 0;
  
  const char *s, *b, *e=str+len;
  for (s=str ; s < e ; i++)
  { 
    for ( ; (s < e) && strchr(" \t\r\n",s[0]); s++) ;
    b=s;
    for ( ; (s < e) && !strchr(" \t\r\n",s[0]); s++) ;
    if (s == b || i > size)
      break;
    a[i]= (uint16) strtol(b,NULL,16);
  }
  return 0;
}




static int
tailoring_append(MY_XML_PARSER *st,
                 const char *fmt, size_t len, const char *attr)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *) st->user_data;
  size_t newlen= i->tailoring_length + len + 64; /* 64 for format */ 
  if (MY_XML_OK == my_charset_file_tailoring_realloc(i, newlen))
  {
    char *dst= i->tailoring + i->tailoring_length;
    sprintf(dst, fmt, (int) len, attr);
    i->tailoring_length+= strlen(dst);
    return MY_XML_OK;
  }
  return MY_XML_ERROR;
}


static int
tailoring_append2(MY_XML_PARSER *st,
                  const char *fmt,
                  size_t len1, const char *attr1,
                  size_t len2, const char *attr2)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *) st->user_data;
  size_t newlen= i->tailoring_length + len1 + len2 + 64; /* 64 for format */
  if (MY_XML_OK == my_charset_file_tailoring_realloc(i, newlen))
  {
    char *dst= i->tailoring + i->tailoring_length;
    sprintf(dst, fmt, (int) len1, attr1, (int) len2, attr2);
    i->tailoring_length+= strlen(dst);
    return MY_XML_OK;
  }
  return MY_XML_ERROR;
}


static size_t
scan_one_character(const char *s, const char *e, my_wc_t *wc)
{
  CHARSET_INFO *cs= &my_charset_utf8_general_ci;
  if (s >= e)
    return 0;

  /* Escape sequence: \uXXXX */
  if (s[0] == '\\' && s + 2 < e && s[1] == 'u' && my_isxdigit(cs, s[2]))
  {
    size_t len= 3; /* We have at least one digit */
    for (s+= 3; s < e && my_isxdigit(cs, s[0]); s++, len++)
    {
    }
    wc[0]= 0;
    return len;
  }
  else if ((s[0] & 0x80) == 0) /* 7-bit character */
  {
    wc[0]= 0;
    return 1;
  }
  else /* Non-escaped character */
  {
    int rc= cs->cset->mb_wc(cs, wc, (uchar *) s, (uchar *) e);
    if (rc > 0)
      return (size_t) rc;
  }
  return 0;
}


static int
tailoring_append_abbreviation(MY_XML_PARSER *st,
                              const char *fmt, size_t len, const char *attr)
{
  size_t clen;
  const char *attrend= attr + len;
  my_wc_t wc;

  for ( ; (clen= scan_one_character(attr, attrend, &wc)) > 0; attr+= clen)
  {
    assert(attr < attrend);
    if (tailoring_append(st, fmt, clen, attr) != MY_XML_OK)
      return MY_XML_ERROR;
  }
  return MY_XML_OK;
}


static int cs_enter(MY_XML_PARSER *st,const char *attr, size_t len)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *)st->user_data;
  struct my_cs_file_section_st *s= cs_file_sec(attr,len);
  int state= s ? s->state : 0;
  
  switch (state) {
  case 0:
    i->loader->reporter(WARNING_LEVEL, "Unknown LDML tag: '%.*s'", len, attr);
    break;

  case _CS_CHARSET:
    my_charset_file_reset_charset(i);
    break;

  case _CS_COLLATION:
    my_charset_file_reset_collation(i);
    break;

  case _CS_RESET:
    return tailoring_append(st, " &", 0, NULL);

  default:
    break;
  }
  return MY_XML_OK;
}


static int cs_leave(MY_XML_PARSER *st,const char *attr, size_t len)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *)st->user_data;
  struct my_cs_file_section_st *s= cs_file_sec(attr,len);
  int    state= s ? s->state : 0;
  int    rc;
  
  switch(state){
  case _CS_COLLATION:
    if (i->tailoring_length)
      i->cs.tailoring= i->tailoring;
    rc= i->loader->add_collation ? i->loader->add_collation(&i->cs) : MY_XML_OK;
    break;

  /* Rules: Logical Reset Positions */
  case _CS_RESET_FIRST_NON_IGNORABLE:
    rc= tailoring_append(st, "[first non-ignorable]", 0, NULL);
    break;

  case _CS_RESET_LAST_NON_IGNORABLE:
    rc= tailoring_append(st, "[last non-ignorable]", 0, NULL);
    break;

  case _CS_RESET_FIRST_PRIMARY_IGNORABLE:
    rc= tailoring_append(st, "[first primary ignorable]", 0, NULL);
    break;

  case _CS_RESET_LAST_PRIMARY_IGNORABLE:
    rc= tailoring_append(st, "[last primary ignorable]", 0, NULL);
    break;

  case _CS_RESET_FIRST_SECONDARY_IGNORABLE:
    rc= tailoring_append(st, "[first secondary ignorable]", 0, NULL);
    break;

  case _CS_RESET_LAST_SECONDARY_IGNORABLE:
    rc= tailoring_append(st, "[last secondary ignorable]", 0, NULL);
    break;

  case _CS_RESET_FIRST_TERTIARY_IGNORABLE:
    rc= tailoring_append(st, "[first tertiary ignorable]", 0, NULL);
    break;

  case _CS_RESET_LAST_TERTIARY_IGNORABLE:
    rc= tailoring_append(st, "[last tertiary ignorable]", 0, NULL);
    break;

  case _CS_RESET_FIRST_TRAILING:
    rc= tailoring_append(st, "[first trailing]", 0, NULL);
    break;

  case _CS_RESET_LAST_TRAILING:
    rc= tailoring_append(st, "[last trailing]", 0, NULL);
    break;

  case _CS_RESET_FIRST_VARIABLE:
    rc= tailoring_append(st, "[first variable]", 0, NULL);
    break;

  case _CS_RESET_LAST_VARIABLE:
    rc= tailoring_append(st, "[last variable]", 0, NULL);
    break;

  default:
    rc=MY_XML_OK;
  }
  return rc;
}


static const char *diff_fmt[5]=
{
  "<%.*s",
  "<<%.*s",
  "<<<%.*s",
  "<<<<%.*s",
  "=%.*s"
};


static const char *context_diff_fmt[5]=
{
  "<%.*s|%.*s",
  "<<%.*s|%.*s",
  "<<<%.*s|%.*s",
  "<<<<%.*s|%.*s",
  "=%.*s|%.*s"
};


static int cs_value(MY_XML_PARSER *st,const char *attr, size_t len)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *)st->user_data;
  struct my_cs_file_section_st *s;
  int    state= (int)((s= cs_file_sec(st->attr.start,
                                      st->attr.end - st->attr.start)) ?
                      s->state : 0);
  int rc= MY_XML_OK;

  switch (state) {
  case _CS_MISC:
  case _CS_FAMILY:
  case _CS_ORDER:
    break;
  case _CS_ID:
    i->cs.number= strtol(attr,(char**)NULL,10);
    break;
  case _CS_BINARY_ID:
    i->cs.binary_number= strtol(attr,(char**)NULL,10);
    break;
  case _CS_PRIMARY_ID:
    i->cs.primary_number= strtol(attr,(char**)NULL,10);
    break;
  case _CS_COLNAME:
    i->cs.name=mstr(i->name,attr,len,MY_CS_NAME_SIZE-1);
    break;
  case _CS_CSNAME:
    i->cs.csname=mstr(i->csname,attr,len,MY_CS_NAME_SIZE-1);
    break;
  case _CS_CSDESCRIPT:
    i->cs.comment=mstr(i->comment,attr,len,MY_CS_CSDESCR_SIZE-1);
    break;
  case _CS_FLAG:
    if (!strncmp("primary",attr,len))
      i->cs.state|= MY_CS_PRIMARY;
    else if (!strncmp("binary",attr,len))
      i->cs.state|= MY_CS_BINSORT;
    else if (!strncmp("compiled",attr,len))
      i->cs.state|= MY_CS_COMPILED;
    break;
  case _CS_UPPERMAP:
    fill_uchar(i->to_upper,MY_CS_TO_UPPER_TABLE_SIZE,attr,len);
    i->cs.to_upper=i->to_upper;
    break;
  case _CS_LOWERMAP:
    fill_uchar(i->to_lower,MY_CS_TO_LOWER_TABLE_SIZE,attr,len);
    i->cs.to_lower=i->to_lower;
    break;
  case _CS_UNIMAP:
    fill_uint16(i->tab_to_uni,MY_CS_TO_UNI_TABLE_SIZE,attr,len);
    i->cs.tab_to_uni=i->tab_to_uni;
    break;
  case _CS_COLLMAP:
    fill_uchar(i->sort_order,MY_CS_SORT_ORDER_TABLE_SIZE,attr,len);
    i->cs.sort_order=i->sort_order;
    break;
  case _CS_CTYPEMAP:
    fill_uchar(i->ctype,MY_CS_CTYPE_TABLE_SIZE,attr,len);
    i->cs.ctype=i->ctype;
    break;

  /* Special purpose commands */
  case _CS_UCA_VERSION:
    rc= tailoring_append(st, "[version %.*s]", len, attr);
    break;

  case _CS_CL_SUPPRESS_CONTRACTIONS:
    rc= tailoring_append(st, "[suppress contractions %.*s]", len, attr);
    break;

  case _CS_CL_OPTIMIZE:
    rc= tailoring_append(st, "[optimize %.*s]", len, attr);
    break;

  case _CS_CL_SHIFT_AFTER_METHOD:
    rc= tailoring_append(st, "[shift-after-method %.*s]", len, attr);
    break;

  /* Collation Settings */
  case _CS_ST_STRENGTH:
    /* 1, 2, 3, 4, 5, or primary, secondary, tertiary, quaternary, identical */
    rc= tailoring_append(st, "[strength %.*s]", len, attr);
    break;

  case _CS_ST_ALTERNATE:
    /* non-ignorable, shifted */
    rc= tailoring_append(st, "[alternate %.*s]", len, attr);
    break;

  case _CS_ST_BACKWARDS:
    /* on, off, 2 */
    rc= tailoring_append(st, "[backwards %.*s]", len, attr);
    break;

  case _CS_ST_NORMALIZATION:
    /*
      TODO for WL#896: check collations for normalization: vi.xml
      We want precomposed characters work well at this point.
    */
    /* on, off */
    rc= tailoring_append(st, "[normalization %.*s]", len, attr);
    break;

  case _CS_ST_CASE_LEVEL:
    /* on, off */
    rc= tailoring_append(st, "[caseLevel %.*s]", len, attr);
    break;

  case _CS_ST_CASE_FIRST:
    /* upper, lower, off */
    rc= tailoring_append(st, "[caseFirst %.*s]", len, attr);
    break;

  case _CS_ST_HIRAGANA_QUATERNARY:
    /* on, off */
    rc= tailoring_append(st, "[hiraganaQ %.*s]", len, attr);
    break;

  case _CS_ST_NUMERIC:
    /* on, off */
    rc= tailoring_append(st, "[numeric %.*s]", len, attr);
    break;

  case _CS_ST_VARIABLE_TOP:
    /* TODO for WL#896: check value format */
    rc= tailoring_append(st, "[variableTop %.*s]", len, attr);
    break;

  case _CS_ST_MATCH_BOUNDARIES:
    /* none, whole-character, whole-word */
    rc= tailoring_append(st, "[match-boundaries %.*s]", len, attr);
    break;

  case _CS_ST_MATCH_STYLE:
    /* minimal, medial, maximal */
    rc= tailoring_append(st, "[match-style %.*s]", len, attr);
    break;


  /* Rules */
  case _CS_RESET:
    rc= tailoring_append(st, "%.*s", len, attr);
    break;

  case _CS_DIFF1:
  case _CS_DIFF2:
  case _CS_DIFF3:
  case _CS_DIFF4:
  case _CS_IDENTICAL:
    rc= tailoring_append(st, diff_fmt[state - _CS_DIFF1], len, attr);
    break;


  /* Rules: Expansion */
  case _CS_EXP_EXTEND:
    rc= tailoring_append(st, " / %.*s", len, attr);
    break;

  case _CS_EXP_DIFF1:
  case _CS_EXP_DIFF2:
  case _CS_EXP_DIFF3:
  case _CS_EXP_DIFF4:
  case _CS_EXP_IDENTICAL:
    if (i->context[0])
    {
      rc= tailoring_append2(st, context_diff_fmt[state - _CS_EXP_DIFF1],
                            strlen(i->context), i->context, len, attr);
      i->context[0]= 0;
    }
    else
      rc= tailoring_append(st, diff_fmt[state  - _CS_EXP_DIFF1], len, attr);
    break;

  /* Rules: Context */
  case _CS_CONTEXT:
    if (len < sizeof(i->context))
    {
      memcpy(i->context, attr, len);
      i->context[len]= '\0';
    }
    break;

  /* Rules: Abbreviating Ordering Specifications */
  case _CS_A_DIFF1:
  case _CS_A_DIFF2:
  case _CS_A_DIFF3:
  case _CS_A_DIFF4:
  case _CS_A_IDENTICAL:
    rc= tailoring_append_abbreviation(st, diff_fmt[state - _CS_A_DIFF1], len, attr);
    break;

  /* Rules: Placing Characters Before Others */
  case _CS_RESET_BEFORE:
    /*
      TODO for WL#896: Add this check into text customization parser:
      It is an error if the strength of the before relation is not identical
      to the relation after the reset. We'll need this for WL#896.
    */
    rc= tailoring_append(st, "[before %.*s]", len, attr);
    break;


  default:
    break;
  }

  return rc;
}


my_bool
my_parse_charset_xml(MY_CHARSET_LOADER *loader, const char *buf, size_t len)
{
  MY_XML_PARSER p;
  struct my_cs_file_info info;
  my_bool rc;
  
  my_charset_file_init(&info);
  my_xml_parser_create(&p);
  my_xml_set_enter_handler(&p,cs_enter);
  my_xml_set_value_handler(&p,cs_value);
  my_xml_set_leave_handler(&p,cs_leave);
  info.loader= loader;
  my_xml_set_user_data(&p, (void *) &info);
  rc= (my_xml_parse(&p,buf,len) == MY_XML_OK) ? FALSE : TRUE;
  my_xml_parser_free(&p);
  my_charset_file_free(&info);
  if (rc != MY_XML_OK)
  {
    const char *errstr= my_xml_error_string(&p);
    if (sizeof(loader->error) > 32 + strlen(errstr))
    {
      /* We cannot use my_snprintf() here. See previous comment. */
      sprintf(loader->error, "at line %d pos %d: %s",
                my_xml_error_lineno(&p)+1,
                (int) my_xml_error_pos(&p),
                my_xml_error_string(&p));
    }
  }
  return rc;
}


/*
  Check repertoire: detect pure ascii strings
*/
uint
my_string_repertoire(const CHARSET_INFO *cs, const char *str, size_t length)
{
  const char *strend= str + length;
  if (cs->mbminlen == 1)
  {
    for ( ; str < strend; str++)
    {
      if (((uchar) *str) > 0x7F)
        return MY_REPERTOIRE_UNICODE30;
    }
  }
  else
  {
    my_wc_t wc;
    int chlen;
    for (;
         (chlen= cs->cset->mb_wc(cs, &wc, (uchar*) str, (uchar*) strend)) > 0;
         str+= chlen)
    {
      if (wc > 0x7F)
        return MY_REPERTOIRE_UNICODE30;
    }
  }
  return MY_REPERTOIRE_ASCII;
}


/*
  Returns repertoire for charset
*/
uint my_charset_repertoire(const CHARSET_INFO *cs)
{
  return cs->state & MY_CS_PUREASCII ?
    MY_REPERTOIRE_ASCII : MY_REPERTOIRE_UNICODE30;
}


/*
  Detect whether a character set is ASCII compatible.

  Returns TRUE for:
  
  - all 8bit character sets whose Unicode mapping of 0x7B is '{'
    (ignores swe7 which maps 0x7B to "LATIN LETTER A WITH DIAERESIS")
  
  - all multi-byte character sets having mbminlen == 1
    (ignores ucs2 whose mbminlen is 2)
  
  TODO:
  
  When merging to 5.2, this function should be changed
  to check a new flag MY_CS_NONASCII, 
  
     return (cs->flag & MY_CS_NONASCII) ? 0 : 1;
  
  This flag was previously added into 5.2 under terms
  of WL#3759 "Optimize identifier conversion in client-server protocol"
  especially to mark character sets not compatible with ASCII.
  
  We won't backport this flag to 5.0 or 5.1.
  This function is Ok for 5.0 and 5.1, because we're not going
  to introduce new tricky character sets between 5.0 and 5.2.
*/
my_bool
my_charset_is_ascii_based(const CHARSET_INFO *cs)
{
  return 
    (cs->mbmaxlen == 1 && cs->tab_to_uni && cs->tab_to_uni['{'] == '{') ||
    (cs->mbminlen == 1 && cs->mbmaxlen > 1);
}


/*
  Detect if a character set is 8bit,
  and it is pure ascii, i.e. doesn't have
  characters outside U+0000..U+007F
  This functions is shared between "conf_to_src"
  and dynamic charsets loader in "mysqld".
*/
my_bool
my_charset_is_8bit_pure_ascii(const CHARSET_INFO *cs)
{
  size_t code;
  if (!cs->tab_to_uni)
    return 0;
  for (code= 0; code < 256; code++)
  {
    if (cs->tab_to_uni[code] > 0x7F)
      return 0;
  }
  return 1;
}


/*
  Shared function between conf_to_src and mysys.
  Check if a 8bit character set is compatible with
  ascii on the range 0x00..0x7F.
*/
my_bool
my_charset_is_ascii_compatible(const CHARSET_INFO *cs)
{
  uint i;
  if (!cs->tab_to_uni)
    return 1;
  for (i= 0; i < 128; i++)
  {
    if (cs->tab_to_uni[i] != i)
      return 0;
  }
  return 1;
}


/*
  Convert a string between two character sets.
  'to' must be large enough to store (form_length * to_cs->mbmaxlen) bytes.

  @param  to[OUT]       Store result here
  @param  to_length     Size of "to" buffer
  @param  to_cs         Character set of result string
  @param  from          Copy from here
  @param  from_length   Length of the "from" string
  @param  from_cs       Character set of the "from" string
  @param  errors[OUT]   Number of conversion errors

  @return Number of bytes copied to 'to' string
*/

static size_t
my_convert_internal(char *to, size_t to_length,
                    const CHARSET_INFO *to_cs,
                    const char *from, size_t from_length,
                    const CHARSET_INFO *from_cs, uint *errors)
{
  int         cnvres;
  my_wc_t     wc;
  const uchar *from_end= (const uchar*) from + from_length;
  char *to_start= to;
  uchar *to_end= (uchar*) to + to_length;
  my_charset_conv_mb_wc mb_wc= from_cs->cset->mb_wc;
  my_charset_conv_wc_mb wc_mb= to_cs->cset->wc_mb;
  uint error_count= 0;

  while (1)
  {
    if ((cnvres= (*mb_wc)(from_cs, &wc, (uchar*) from, from_end)) > 0)
      from+= cnvres;
    else if (cnvres == MY_CS_ILSEQ)
    {
      error_count++;
      from++;
      wc= '?';
    }
    else if (cnvres > MY_CS_TOOSMALL)
    {
      /*
        A correct multibyte sequence detected
        But it doesn't have Unicode mapping.
      */
      error_count++;
      from+= (-cnvres);
      wc= '?';
    }
    else
      break;  // Not enough characters

outp:
    if ((cnvres= (*wc_mb)(to_cs, wc, (uchar*) to, to_end)) > 0)
      to+= cnvres;
    else if (cnvres == MY_CS_ILUNI && wc != '?')
    {
      error_count++;
      wc= '?';
      goto outp;
    }
    else
      break;
  }
  *errors= error_count;
  return (uint32) (to - to_start);
}


/*
  Convert a string between two character sets.
   Optimized for quick copying of ASCII characters in the range 0x00..0x7F.
  'to' must be large enough to store (form_length * to_cs->mbmaxlen) bytes.

  @param  to[OUT]       Store result here
  @param  to_length     Size of "to" buffer
  @param  to_cs         Character set of result string
  @param  from          Copy from here
  @param  from_length   Length of the "from" string
  @param  from_cs       Character set of the "from" string
  @param  errors[OUT]   Number of conversion errors

  @return Number of bytes copied to 'to' string
*/

size_t
my_convert(char *to, size_t to_length, const CHARSET_INFO *to_cs,
           const char *from, size_t from_length,
           const CHARSET_INFO *from_cs, uint *errors)
{
  size_t length, length2;
  /*
    If any of the character sets is not ASCII compatible,
    immediately switch to slow mb_wc->wc_mb method.
  */
  if ((to_cs->state | from_cs->state) & MY_CS_NONASCII)
    return my_convert_internal(to, to_length, to_cs,
                               from, from_length, from_cs, errors);

  length= length2= MY_MIN(to_length, from_length);

#if defined(__i386__)
  /*
    Special loop for i386, it allows to refer to a
    non-aligned memory block as UINT32, which makes
    it possible to copy four bytes at once. This
    gives about 10% performance improvement comparing
    to byte-by-byte loop.
  */
  for ( ; length >= 4; length-= 4, from+= 4, to+= 4)
  {
    if ((*(uint32*)from) & 0x80808080)
      break;
    *((uint32*) to)= *((const uint32*) from);
  }
#endif /* __i386__ */

  for (; ; *to++= *from++, length--)
  {
    if (!length)
    {
      *errors= 0;
      return length2;
    }
    if (*((unsigned char*) from) > 0x7F) /* A non-ASCII character */
    {
      size_t copied_length= length2 - length;
      to_length-= copied_length;
      from_length-= copied_length;
      return copied_length + my_convert_internal(to, to_length, to_cs,
                                                 from, from_length, from_cs,
                                                 errors);
    }
  }

  assert(FALSE); // Should never get to here
  return 0;           // Make compiler happy
}

/**
  Get the length of the first code in given sequence of chars.
  This func is introduced because we can't determine the length by
  checking the first byte only for gb18030, so we first try my_mbcharlen,
  and then my_mbcharlen_2 if necessary to get the length

  @param[in]  cs   charset_info
  @param[in]  s    start of the char sequence
  @param[in]  e    end of the char sequence
  @return     The length of the first code, or 0 for invalid code
*/
uint
my_mbcharlen_ptr(const CHARSET_INFO *cs, const char *s, const char *e)
{
  uint len= my_mbcharlen(cs, (uchar) *s);
  if (len == 0 && my_mbmaxlenlen(cs) == 2 && s + 1 < e)
  {
    len= my_mbcharlen_2(cs, (uchar) *s, (uchar) *(s + 1));
    /* It could be either a valid multi-byte GB18030 code, or invalid
    gb18030 code if return value is 0 */
    assert(len == 0 || len == 2 || len == 4);
  }

  return len;
}