root/ext/standard/html.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. get_next_char
  2. php_next_utf8_char
  3. determine_charset
  4. php_utf32_utf8
  5. php_mb2_int_to_char
  6. php_mb3_int_to_char
  7. unimap_bsearch
  8. map_from_unicode
  9. map_to_unicode
  10. unicode_cp_is_allowed
  11. numeric_entity_is_allowed
  12. process_numeric_entity
  13. process_named_entity_html
  14. resolve_named_entity_html
  15. write_octet_sequence
  16. traverse_for_entities
  17. unescape_inverse_map
  18. determine_entity_table
  19. php_unescape_html_entities
  20. php_escape_html_entities
  21. find_entity_for_char
  22. find_entity_for_char_basic
  23. php_escape_html_entities_ex
  24. php_html_entities
  25. register_html_constants
  26. PHP_FUNCTION
  27. PHP_FUNCTION
  28. PHP_FUNCTION
  29. PHP_FUNCTION
  30. write_s3row_data
  31. PHP_FUNCTION

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2015 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Rasmus Lerdorf <rasmus@php.net>                             |
   |          Jaakko Hyvätti <jaakko.hyvatti@iki.fi>                      |
   |          Wez Furlong    <wez@thebrainroom.com>                       |
   |          Gustavo Lopes  <cataphract@php.net>                         |
   +----------------------------------------------------------------------+
*/

/* $Id$ */

/*
 * HTML entity resources:
 *
 * http://www.unicode.org/Public/MAPPINGS/OBSOLETE/UNI2SGML.TXT
 *
 * XHTML 1.0 DTD
 * http://www.w3.org/TR/2002/REC-xhtml1-20020801/dtds.html#h-A2
 *
 * From HTML 4.01 strict DTD:
 * http://www.w3.org/TR/html4/HTMLlat1.ent
 * http://www.w3.org/TR/html4/HTMLsymbol.ent
 * http://www.w3.org/TR/html4/HTMLspecial.ent
 *
 * HTML 5:
 * http://dev.w3.org/html5/spec/Overview.html#named-character-references
 */

#include "php.h"
#if PHP_WIN32
#include "config.w32.h"
#else
#include <php_config.h>
#endif
#include "php_standard.h"
#include "php_string.h"
#include "SAPI.h"
#if HAVE_LOCALE_H
#include <locale.h>
#endif
#if HAVE_LANGINFO_H
#include <langinfo.h>
#endif

#include <zend_hash.h>
#include "html_tables.h"

/* Macro for disabling flag of translation of non-basic entities where this isn't supported.
 * Not appropriate for html_entity_decode/htmlspecialchars_decode */
#define LIMIT_ALL(all, doctype, charset) do { \
        (all) = (all) && !CHARSET_PARTIAL_SUPPORT((charset)) && ((doctype) != ENT_HTML_DOC_XML1); \
} while (0)

#define MB_FAILURE(pos, advance) do { \
        *cursor = pos + (advance); \
        *status = FAILURE; \
        return 0; \
} while (0)

#define CHECK_LEN(pos, chars_need) ((str_len - (pos)) >= (chars_need))

/* valid as single byte character or leading byte */
#define utf8_lead(c)  ((c) < 0x80 || ((c) >= 0xC2 && (c) <= 0xF4))
/* whether it's actually valid depends on other stuff;
 * this macro cannot check for non-shortest forms, surrogates or
 * code points above 0x10FFFF */
#define utf8_trail(c) ((c) >= 0x80 && (c) <= 0xBF)

#define gb2312_lead(c) ((c) != 0x8E && (c) != 0x8F && (c) != 0xA0 && (c) != 0xFF)
#define gb2312_trail(c) ((c) >= 0xA1 && (c) <= 0xFE)

#define sjis_lead(c) ((c) != 0x80 && (c) != 0xA0 && (c) < 0xFD)
#define sjis_trail(c) ((c) >= 0x40  && (c) != 0x7F && (c) < 0xFD)

/* {{{ get_next_char
 */
static inline unsigned int get_next_char(
                enum entity_charset charset,
                const unsigned char *str,
                size_t str_len,
                size_t *cursor,
                int *status)
{
        size_t pos = *cursor;
        unsigned int this_char = 0;

        *status = SUCCESS;
        assert(pos <= str_len);

        if (!CHECK_LEN(pos, 1))
                MB_FAILURE(pos, 1);

        switch (charset) {
        case cs_utf_8:
                {
                        /* We'll follow strategy 2. from section 3.6.1 of UTR #36:
                         * "In a reported illegal byte sequence, do not include any
                         *  non-initial byte that encodes a valid character or is a leading
                         *  byte for a valid sequence." */
                        unsigned char c;
                        c = str[pos];
                        if (c < 0x80) {
                                this_char = c;
                                pos++;
                        } else if (c < 0xc2) {
                                MB_FAILURE(pos, 1);
                        } else if (c < 0xe0) {
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);

                                if (!utf8_trail(str[pos + 1])) {
                                        MB_FAILURE(pos, utf8_lead(str[pos + 1]) ? 1 : 2);
                                }
                                this_char = ((c & 0x1f) << 6) | (str[pos + 1] & 0x3f);
                                if (this_char < 0x80) { /* non-shortest form */
                                        MB_FAILURE(pos, 2);
                                }
                                pos += 2;
                        } else if (c < 0xf0) {
                                size_t avail = str_len - pos;

                                if (avail < 3 ||
                                                !utf8_trail(str[pos + 1]) || !utf8_trail(str[pos + 2])) {
                                        if (avail < 2 || utf8_lead(str[pos + 1]))
                                                MB_FAILURE(pos, 1);
                                        else if (avail < 3 || utf8_lead(str[pos + 2]))
                                                MB_FAILURE(pos, 2);
                                        else
                                                MB_FAILURE(pos, 3);
                                }

                                this_char = ((c & 0x0f) << 12) | ((str[pos + 1] & 0x3f) << 6) | (str[pos + 2] & 0x3f);
                                if (this_char < 0x800) { /* non-shortest form */
                                        MB_FAILURE(pos, 3);
                                } else if (this_char >= 0xd800 && this_char <= 0xdfff) { /* surrogate */
                                        MB_FAILURE(pos, 3);
                                }
                                pos += 3;
                        } else if (c < 0xf5) {
                                size_t avail = str_len - pos;

                                if (avail < 4 ||
                                                !utf8_trail(str[pos + 1]) || !utf8_trail(str[pos + 2]) ||
                                                !utf8_trail(str[pos + 3])) {
                                        if (avail < 2 || utf8_lead(str[pos + 1]))
                                                MB_FAILURE(pos, 1);
                                        else if (avail < 3 || utf8_lead(str[pos + 2]))
                                                MB_FAILURE(pos, 2);
                                        else if (avail < 4 || utf8_lead(str[pos + 3]))
                                                MB_FAILURE(pos, 3);
                                        else
                                                MB_FAILURE(pos, 4);
                                }
                                
                                this_char = ((c & 0x07) << 18) | ((str[pos + 1] & 0x3f) << 12) | ((str[pos + 2] & 0x3f) << 6) | (str[pos + 3] & 0x3f);
                                if (this_char < 0x10000 || this_char > 0x10FFFF) { /* non-shortest form or outside range */
                                        MB_FAILURE(pos, 4);
                                }
                                pos += 4;
                        } else {
                                MB_FAILURE(pos, 1);
                        }
                }
                break;

        case cs_big5:
                /* reference http://demo.icu-project.org/icu-bin/convexp?conv=big5 */
                {
                        unsigned char c = str[pos];
                        if (c >= 0x81 && c <= 0xFE) {
                                unsigned char next;
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);

                                next = str[pos + 1];

                                if ((next >= 0x40 && next <= 0x7E) ||
                                                (next >= 0xA1 && next <= 0xFE)) {
                                        this_char = (c << 8) | next;
                                } else {
                                        MB_FAILURE(pos, 1);
                                }
                                pos += 2;
                        } else {
                                this_char = c;
                                pos += 1;
                        }
                }
                break;

        case cs_big5hkscs:
                {
                        unsigned char c = str[pos];
                        if (c >= 0x81 && c <= 0xFE) {
                                unsigned char next;
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);

                                next = str[pos + 1];

                                if ((next >= 0x40 && next <= 0x7E) ||
                                                (next >= 0xA1 && next <= 0xFE)) {
                                        this_char = (c << 8) | next;
                                } else if (next != 0x80 && next != 0xFF) {
                                        MB_FAILURE(pos, 1);
                                } else {
                                        MB_FAILURE(pos, 2);
                                }
                                pos += 2;
                        } else {
                                this_char = c;
                                pos += 1;
                        }
                }
                break;

        case cs_gb2312: /* EUC-CN */
                {
                        unsigned char c = str[pos];
                        if (c >= 0xA1 && c <= 0xFE) {
                                unsigned char next;
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);

                                next = str[pos + 1];

                                if (gb2312_trail(next)) {
                                        this_char = (c << 8) | next;
                                } else if (gb2312_lead(next)) {
                                        MB_FAILURE(pos, 1);
                                } else {
                                        MB_FAILURE(pos, 2);
                                }
                                pos += 2;
                        } else if (gb2312_lead(c)) {
                                this_char = c;
                                pos += 1;
                        } else {
                                MB_FAILURE(pos, 1);
                        }
                }
                break;

        case cs_sjis:
                {
                        unsigned char c = str[pos];
                        if ((c >= 0x81 && c <= 0x9F) || (c >= 0xE0 && c <= 0xFC)) {
                                unsigned char next;
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);

                                next = str[pos + 1];

                                if (sjis_trail(next)) {
                                        this_char = (c << 8) | next;
                                } else if (sjis_lead(next)) {
                                        MB_FAILURE(pos, 1);
                                } else {
                                        MB_FAILURE(pos, 2);
                                }
                                pos += 2;
                        } else if (c < 0x80 || (c >= 0xA1 && c <= 0xDF)) {
                                this_char = c;
                                pos += 1;
                        } else {
                                MB_FAILURE(pos, 1);
                        }
                }
                break;

        case cs_eucjp:
                {
                        unsigned char c = str[pos];

                        if (c >= 0xA1 && c <= 0xFE) {
                                unsigned next;
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);
                                next = str[pos + 1];

                                if (next >= 0xA1 && next <= 0xFE) {
                                        /* this a jis kanji char */
                                        this_char = (c << 8) | next;
                                } else {
                                        MB_FAILURE(pos, (next != 0xA0 && next != 0xFF) ? 1 : 2);
                                }
                                pos += 2;
                        } else if (c == 0x8E) {
                                unsigned next;
                                if (!CHECK_LEN(pos, 2))
                                        MB_FAILURE(pos, 1);

                                next = str[pos + 1];
                                if (next >= 0xA1 && next <= 0xDF) {
                                        /* JIS X 0201 kana */
                                        this_char = (c << 8) | next;
                                } else {
                                        MB_FAILURE(pos, (next != 0xA0 && next != 0xFF) ? 1 : 2);
                                }
                                pos += 2;
                        } else if (c == 0x8F) {
                                size_t avail = str_len - pos;

                                if (avail < 3 || !(str[pos + 1] >= 0xA1 && str[pos + 1] <= 0xFE) ||
                                                !(str[pos + 2] >= 0xA1 && str[pos + 2] <= 0xFE)) {
                                        if (avail < 2 || (str[pos + 1] != 0xA0 && str[pos + 1] != 0xFF))
                                                MB_FAILURE(pos, 1);
                                        else if (avail < 3 || (str[pos + 2] != 0xA0 && str[pos + 2] != 0xFF))
                                                MB_FAILURE(pos, 2);
                                        else
                                                MB_FAILURE(pos, 3);
                                } else {
                                        /* JIS X 0212 hojo-kanji */
                                        this_char = (c << 16) | (str[pos + 1] << 8) | str[pos + 2];
                                }
                                pos += 3;
                        } else if (c != 0xA0 && c != 0xFF) {
                                /* character encoded in 1 code unit */
                                this_char = c;
                                pos += 1;
                        } else {
                                MB_FAILURE(pos, 1);
                        }
                }
                break;
        default:
                /* single-byte charsets */
                this_char = str[pos++];
                break;
        }

        *cursor = pos;
        return this_char;
}
/* }}} */

/* {{{ php_next_utf8_char
 * Public interface for get_next_char used with UTF-8 */
 PHPAPI unsigned int php_next_utf8_char(
                const unsigned char *str,
                size_t str_len,
                size_t *cursor,
                int *status)
{
        return get_next_char(cs_utf_8, str, str_len, cursor, status);
}
/* }}} */

/* {{{ entity_charset determine_charset
 * returns the charset identifier based on current locale or a hint.
 * defaults to UTF-8 */
static enum entity_charset determine_charset(char *charset_hint TSRMLS_DC)
{
        int i;
        enum entity_charset charset = cs_utf_8;
        int len = 0;
        const zend_encoding *zenc;

        /* Default is now UTF-8 */
        if (charset_hint == NULL)
                return cs_utf_8;

        if ((len = strlen(charset_hint)) != 0) {
                goto det_charset;
        }

        zenc = zend_multibyte_get_internal_encoding(TSRMLS_C);
        if (zenc != NULL) {
                charset_hint = (char *)zend_multibyte_get_encoding_name(zenc);
                if (charset_hint != NULL && (len=strlen(charset_hint)) != 0) {
                        if ((len == 4) /* sizeof (none|auto|pass) */ &&
                                        (!memcmp("pass", charset_hint, 4) ||
                                         !memcmp("auto", charset_hint, 4) ||
                                         !memcmp("auto", charset_hint, 4))) {
                                charset_hint = NULL;
                                len = 0;
                        } else {
                                goto det_charset;
                        }
                }
        }

        charset_hint = SG(default_charset);
        if (charset_hint != NULL && (len=strlen(charset_hint)) != 0) {
                goto det_charset;
        }

        /* try to detect the charset for the locale */
#if HAVE_NL_LANGINFO && HAVE_LOCALE_H && defined(CODESET)
        charset_hint = nl_langinfo(CODESET);
        if (charset_hint != NULL && (len=strlen(charset_hint)) != 0) {
                goto det_charset;
        }
#endif

#if HAVE_LOCALE_H
        /* try to figure out the charset from the locale */
        {
                char *localename;
                char *dot, *at;

                /* lang[_territory][.codeset][@modifier] */
                localename = setlocale(LC_CTYPE, NULL);

                dot = strchr(localename, '.');
                if (dot) {
                        dot++;
                        /* locale specifies a codeset */
                        at = strchr(dot, '@');
                        if (at)
                                len = at - dot;
                        else
                                len = strlen(dot);
                        charset_hint = dot;
                } else {
                        /* no explicit name; see if the name itself
                         * is the charset */
                        charset_hint = localename;
                        len = strlen(charset_hint);
                }
        }
#endif

det_charset:

        if (charset_hint) {
                int found = 0;
                
                /* now walk the charset map and look for the codeset */
                for (i = 0; charset_map[i].codeset; i++) {
                        if (len == strlen(charset_map[i].codeset) && strncasecmp(charset_hint, charset_map[i].codeset, len) == 0) {
                                charset = charset_map[i].charset;
                                found = 1;
                                break;
                        }
                }
                if (!found) {
                        php_error_docref(NULL TSRMLS_CC, E_WARNING, "charset `%s' not supported, assuming utf-8",
                                        charset_hint);
                }
        }
        return charset;
}
/* }}} */

/* {{{ php_utf32_utf8 */
static inline size_t php_utf32_utf8(unsigned char *buf, unsigned k)
{
        size_t retval = 0;

        /* assert(0x0 <= k <= 0x10FFFF); */

        if (k < 0x80) {
                buf[0] = k;
                retval = 1;
        } else if (k < 0x800) {
                buf[0] = 0xc0 | (k >> 6);
                buf[1] = 0x80 | (k & 0x3f);
                retval = 2;
        } else if (k < 0x10000) {
                buf[0] = 0xe0 | (k >> 12);
                buf[1] = 0x80 | ((k >> 6) & 0x3f);
                buf[2] = 0x80 | (k & 0x3f);
                retval = 3;
        } else {
                buf[0] = 0xf0 | (k >> 18);
                buf[1] = 0x80 | ((k >> 12) & 0x3f);
                buf[2] = 0x80 | ((k >> 6) & 0x3f);
                buf[3] = 0x80 | (k & 0x3f);
                retval = 4;
        }
        /* UTF-8 has been restricted to max 4 bytes since RFC 3629 */

        return retval;
}
/* }}} */

/* {{{ php_mb2_int_to_char
 * Convert back big endian int representation of sequence of one or two 8-bit code units. */
static inline size_t php_mb2_int_to_char(unsigned char *buf, unsigned k)
{
        assert(k <= 0xFFFFU);
        /* one or two bytes */
        if (k <= 0xFFU) { /* 1 */
                buf[0] = k;
                return 1U;
        } else { /* 2 */
                buf[0] = k >> 8;
                buf[1] = k & 0xFFU;
                return 2U;
        }
}
/* }}} */

/* {{{ php_mb3_int_to_char
 * Convert back big endian int representation of sequence of one to three 8-bit code units.
 * For EUC-JP. */
static inline size_t php_mb3_int_to_char(unsigned char *buf, unsigned k)
{
        assert(k <= 0xFFFFFFU);
        /* one to three bytes */
        if (k <= 0xFFU) { /* 1 */
                buf[0] = k;
                return 1U;
        } else if (k <= 0xFFFFU) { /* 2 */
                buf[0] = k >> 8;
                buf[1] = k & 0xFFU;
                return 2U;
        } else {
                buf[0] = k >> 16;
                buf[1] = (k >> 8) & 0xFFU;
                buf[2] = k & 0xFFU;
                return 3U;
        }
}
/* }}} */


/* {{{ unimap_bsearc_cmp
 * Binary search of unicode code points in unicode <--> charset mapping.
 * Returns the code point in the target charset (whose mapping table was given) or 0 if
 * the unicode code point is not in the table.
 */
static inline unsigned char unimap_bsearch(const uni_to_enc *table, unsigned code_key_a, size_t num)
{
        const uni_to_enc *l = table,
                                         *h = &table[num-1],
                                         *m;
        unsigned short code_key;

        /* we have no mappings outside the BMP */
        if (code_key_a > 0xFFFFU)
                return 0;

        code_key = (unsigned short) code_key_a;
        
        while (l <= h) {
                m = l + (h - l) / 2;
                if (code_key < m->un_code_point)
                        h = m - 1;
                else if (code_key > m->un_code_point)
                        l = m + 1;
                else
                        return m->cs_code;
        }
        return 0;
}
/* }}} */

/* {{{ map_from_unicode */
static inline int map_from_unicode(unsigned code, enum entity_charset charset, unsigned *res)
{
        unsigned char found;
        const uni_to_enc *table;
        size_t table_size;

        switch (charset) {
        case cs_8859_1:
                /* identity mapping of code points to unicode */
                if (code > 0xFF) {
                        return FAILURE;
                } 
                *res = code;
                break;

        case cs_8859_5:
                if (code <= 0xA0 || code == 0xAD /* soft hyphen */) {
                        *res = code;
                } else if (code == 0x2116) {
                        *res = 0xF0; /* numero sign */
                } else if (code == 0xA7) {
                        *res = 0xFD; /* section sign */
                } else if (code >= 0x0401 && code <= 0x044F) {
                        if (code == 0x040D || code == 0x0450 || code == 0x045D)
                                return FAILURE;
                        *res = code - 0x360;
                } else {
                        return FAILURE;
                }
                break;
                
        case cs_8859_15:
                if (code < 0xA4 || (code > 0xBE && code <= 0xFF)) {
                        *res = code;
                } else { /* between A4 and 0xBE */
                        found = unimap_bsearch(unimap_iso885915,
                                code, sizeof(unimap_iso885915) / sizeof(*unimap_iso885915));
                        if (found)
                                *res = found;
                        else
                                return FAILURE;
                }
                break;

        case cs_cp1252:
                if (code <= 0x7F || (code >= 0xA0 && code <= 0xFF)) {
                        *res = code;
                } else {
                        found = unimap_bsearch(unimap_win1252,
                                code, sizeof(unimap_win1252) / sizeof(*unimap_win1252));
                        if (found)
                                *res = found;
                        else
                                return FAILURE;
                }
                break;

        case cs_macroman:
                if (code == 0x7F)
                        return FAILURE;
                table = unimap_macroman;
                table_size = sizeof(unimap_macroman) / sizeof(*unimap_macroman);
                goto table_over_7F;
        case cs_cp1251:
                table = unimap_win1251;
                table_size = sizeof(unimap_win1251) / sizeof(*unimap_win1251);
                goto table_over_7F;
        case cs_koi8r:
                table = unimap_koi8r;
                table_size = sizeof(unimap_koi8r) / sizeof(*unimap_koi8r);
                goto table_over_7F;
        case cs_cp866:
                table = unimap_cp866;
                table_size = sizeof(unimap_cp866) / sizeof(*unimap_cp866);
                
table_over_7F:
                if (code <= 0x7F) {
                        *res = code;
                } else {
                        found = unimap_bsearch(table, code, table_size);
                        if (found)
                                *res = found;
                        else
                                return FAILURE;
                }
                break;

        /* from here on, only map the possible characters in the ASCII range.
         * to improve support here, it's a matter of building the unicode mappings.
         * See <http://www.unicode.org/Public/6.0.0/ucd/Unihan.zip> */
        case cs_sjis:
        case cs_eucjp:
                /* we interpret 0x5C as the Yen symbol. This is not universal.
                 * See <http://www.w3.org/Submission/japanese-xml/#ambiguity_of_yen> */
                if (code >= 0x20 && code <= 0x7D) {
                        if (code == 0x5C)
                                return FAILURE;
                        *res = code;
                } else {
                        return FAILURE;
                }
                break;

        case cs_big5:
        case cs_big5hkscs:
        case cs_gb2312:
                if (code >= 0x20 && code <= 0x7D) {
                        *res = code;
                } else {
                        return FAILURE;
                }
                break;

        default:
                return FAILURE;
        }

        return SUCCESS;
}
/* }}} */

/* {{{ */
static inline void map_to_unicode(unsigned code, const enc_to_uni *table, unsigned *res)
{
        /* only single byte encodings are currently supported; assumed code <= 0xFF */
        *res = table->inner[ENT_ENC_TO_UNI_STAGE1(code)]->uni_cp[ENT_ENC_TO_UNI_STAGE2(code)];
}
/* }}} */

/* {{{ unicode_cp_is_allowed */
static inline int unicode_cp_is_allowed(unsigned uni_cp, int document_type)
{
        /* XML 1.0                              HTML 4.01                       HTML 5
         * 0x09..0x0A                   0x09..0x0A                      0x09..0x0A
         * 0x0D                                 0x0D                            0x0C..0x0D
         * 0x0020..0xD7FF               0x20..0x7E                      0x20..0x7E
         *                                              0x00A0..0xD7FF          0x00A0..0xD7FF
         * 0xE000..0xFFFD               0xE000..0x10FFFF        0xE000..0xFDCF
         * 0x010000..0x10FFFF                                           0xFDF0..0x10FFFF (*)
         *
         * (*) exclude code points where ((code & 0xFFFF) >= 0xFFFE)
         *
         * References:
         * XML 1.0:   <http://www.w3.org/TR/REC-xml/#charsets>
         * HTML 4.01: <http://www.w3.org/TR/1999/PR-html40-19990824/sgml/sgmldecl.html>
         * HTML 5:    <http://dev.w3.org/html5/spec/Overview.html#preprocessing-the-input-stream>
         *
         * Not sure this is the relevant part for HTML 5, though. I opted to
         * disallow the characters that would result in a parse error when
         * preprocessing of the input stream. See also section 8.1.3.
         * 
         * It's unclear if XHTML 1.0 allows C1 characters. I'll opt to apply to
         * XHTML 1.0 the same rules as for XML 1.0.
         * See <http://cmsmcq.com/2007/C1.xml>.
         */

        switch (document_type) {
        case ENT_HTML_DOC_HTML401:
                return (uni_cp >= 0x20 && uni_cp <= 0x7E) ||
                        (uni_cp == 0x0A || uni_cp == 0x09 || uni_cp == 0x0D) ||
                        (uni_cp >= 0xA0 && uni_cp <= 0xD7FF) ||
                        (uni_cp >= 0xE000 && uni_cp <= 0x10FFFF);
        case ENT_HTML_DOC_HTML5:
                return (uni_cp >= 0x20 && uni_cp <= 0x7E) ||
                        (uni_cp >= 0x09 && uni_cp <= 0x0D && uni_cp != 0x0B) || /* form feed U+0C allowed */
                        (uni_cp >= 0xA0 && uni_cp <= 0xD7FF) ||
                        (uni_cp >= 0xE000 && uni_cp <= 0x10FFFF &&
                                ((uni_cp & 0xFFFF) < 0xFFFE) && /* last two of each plane (nonchars) disallowed */
                                (uni_cp < 0xFDD0 || uni_cp > 0xFDEF)); /* U+FDD0-U+FDEF (nonchars) disallowed */
        case ENT_HTML_DOC_XHTML:
        case ENT_HTML_DOC_XML1:
                return (uni_cp >= 0x20 && uni_cp <= 0xD7FF) ||
                        (uni_cp == 0x0A || uni_cp == 0x09 || uni_cp == 0x0D) ||
                        (uni_cp >= 0xE000 && uni_cp <= 0x10FFFF && uni_cp != 0xFFFE && uni_cp != 0xFFFF);
        default:
                return 1;
        }
}
/* }}} */

/* {{{ unicode_cp_is_allowed */
static inline int numeric_entity_is_allowed(unsigned uni_cp, int document_type)
{
        /* less restrictive than unicode_cp_is_allowed */
        switch (document_type) {
        case ENT_HTML_DOC_HTML401:
                /* all non-SGML characters (those marked with UNUSED in DESCSET) should be
                 * representable with numeric entities */
                return uni_cp <= 0x10FFFF;
        case ENT_HTML_DOC_HTML5:
                /* 8.1.4. The numeric character reference forms described above are allowed to
                 * reference any Unicode code point other than U+0000, U+000D, permanently
                 * undefined Unicode characters (noncharacters), and control characters other
                 * than space characters (U+0009, U+000A, U+000C and U+000D) */
                /* seems to allow surrogate characters, then */
                return (uni_cp >= 0x20 && uni_cp <= 0x7E) ||
                        (uni_cp >= 0x09 && uni_cp <= 0x0C && uni_cp != 0x0B) || /* form feed U+0C allowed, but not U+0D */
                        (uni_cp >= 0xA0 && uni_cp <= 0x10FFFF &&
                                ((uni_cp & 0xFFFF) < 0xFFFE) && /* last two of each plane (nonchars) disallowed */
                                (uni_cp < 0xFDD0 || uni_cp > 0xFDEF)); /* U+FDD0-U+FDEF (nonchars) disallowed */
        case ENT_HTML_DOC_XHTML:
        case ENT_HTML_DOC_XML1:
                /* OTOH, XML 1.0 requires "character references to match the production for Char
                 * See <http://www.w3.org/TR/REC-xml/#NT-CharRef> */
                return unicode_cp_is_allowed(uni_cp, document_type);
        default:
                return 1;
        }
}
/* }}} */

/* {{{ process_numeric_entity
 * Auxiliary function to traverse_for_entities.
 * On input, *buf should point to the first character after # and on output, it's the last
 * byte read, no matter if there was success or insuccess. 
 */
static inline int process_numeric_entity(const char **buf, unsigned *code_point)
{
        long code_l;
        int hexadecimal = (**buf == 'x' || **buf == 'X'); /* TODO: XML apparently disallows "X" */
        char *endptr;

        if (hexadecimal && (**buf != '\0'))
                (*buf)++;
                        
        /* strtol allows whitespace and other stuff in the beginning
                * we're not interested */
        if ((hexadecimal && !isxdigit(**buf)) ||
                        (!hexadecimal && !isdigit(**buf))) {
                return FAILURE;
        }

        code_l = strtol(*buf, &endptr, hexadecimal ? 16 : 10);
        /* we're guaranteed there were valid digits, so *endptr > buf */
        *buf = endptr;

        if (**buf != ';')
                return FAILURE;

        /* many more are invalid, but that depends on whether it's HTML
         * (and which version) or XML. */
        if (code_l > 0x10FFFFL)
                return FAILURE;

        if (code_point != NULL)
                *code_point = (unsigned)code_l;

        return SUCCESS;
}
/* }}} */

/* {{{ process_named_entity */
static inline int process_named_entity_html(const char **buf, const char **start, size_t *length)
{
        *start = *buf;

        /* "&" is represented by a 0x26 in all supported encodings. That means
         * the byte after represents a character or is the leading byte of an
         * sequence of 8-bit code units. If in the ranges below, it represents
         * necessarily a alpha character because none of the supported encodings
         * has an overlap with ASCII in the leading byte (only on the second one) */
        while ((**buf >= 'a' && **buf <= 'z') ||
                        (**buf >= 'A' && **buf <= 'Z') ||
                        (**buf >= '0' && **buf <= '9')) {
                (*buf)++;
        }

        if (**buf != ';')
                return FAILURE;

        /* cast to size_t OK as the quantity is always non-negative */
        *length = *buf - *start;

        if (*length == 0)
                return FAILURE;

        return SUCCESS;
}
/* }}} */

/* {{{ resolve_named_entity_html */
static inline int resolve_named_entity_html(const char *start, size_t length, const entity_ht *ht, unsigned *uni_cp1, unsigned *uni_cp2)
{
        const entity_cp_map *s;
        ulong hash = zend_inline_hash_func(start, length);

        s = ht->buckets[hash % ht->num_elems];
        while (s->entity) {
                if (s->entity_len == length) {
                        if (memcmp(start, s->entity, length) == 0) {
                                *uni_cp1 = s->codepoint1;
                                *uni_cp2 = s->codepoint2;
                                return SUCCESS;
                        }
                }
                s++;
        }
        return FAILURE;
}
/* }}} */

static inline size_t write_octet_sequence(unsigned char *buf, enum entity_charset charset, unsigned code) {
        /* code is not necessarily a unicode code point */
        switch (charset) {
        case cs_utf_8:
                return php_utf32_utf8(buf, code);

        case cs_8859_1:
        case cs_cp1252:
        case cs_8859_15:
        case cs_koi8r:
        case cs_cp1251:
        case cs_8859_5:
        case cs_cp866:
        case cs_macroman:
                /* single byte stuff */
                *buf = code;
                return 1;

        case cs_big5:
        case cs_big5hkscs:
        case cs_sjis:
        case cs_gb2312:
                /* we don't have complete unicode mappings for these yet in entity_decode,
                 * and we opt to pass through the octet sequences for these in htmlentities
                 * instead of converting to an int and then converting back. */
#if 0
                return php_mb2_int_to_char(buf, code);
#else
#ifdef ZEND_DEBUG
                assert(code <= 0xFFU);
#endif
                *buf = code;
                return 1;
#endif

        case cs_eucjp:
#if 0 /* idem */
                return php_mb2_int_to_char(buf, code);
#else
#ifdef ZEND_DEBUG
                assert(code <= 0xFFU);
#endif
                *buf = code;
                return 1;
#endif

        default:
                assert(0);
                return 0;
        }
}

/* {{{ traverse_for_entities
 * Auxiliary function to php_unescape_html_entities().
 * - The argument "all" determines if all numeric entities are decode or only those
 *   that correspond to quotes (depending on quote_style).
 */
/* maximum expansion (factor 1.2) for HTML 5 with &nGt; and &nLt; */
/* +2 is 1 because of rest (probably unnecessary), 1 because of terminating 0 */
#define TRAVERSE_FOR_ENTITIES_EXPAND_SIZE(oldlen) ((oldlen) + (oldlen) / 5 + 2)
static void traverse_for_entities(
        const char *old,
        size_t oldlen,
        char *ret, /* should have allocated TRAVERSE_FOR_ENTITIES_EXPAND_SIZE(olden) */
        size_t *retlen,
        int all,
        int flags,
        const entity_ht *inv_map,
        enum entity_charset charset)
{
        const char *p,
                           *lim;
        char       *q;
        int doctype = flags & ENT_HTML_DOC_TYPE_MASK;

        lim = old + oldlen; /* terminator address */
        assert(*lim == '\0');

        for (p = old, q = ret; p < lim;) {
                unsigned code, code2 = 0;
                const char *next = NULL; /* when set, next > p, otherwise possible inf loop */

                /* Shift JIS, Big5 and HKSCS use multi-byte encodings where an
                 * ASCII range byte can be part of a multi-byte sequence.
                 * However, they start at 0x40, therefore if we find a 0x26 byte,
                 * we're sure it represents the '&' character. */

                /* assumes there are no single-char entities */
                if (p[0] != '&' || (p + 3 >= lim)) {
                        *(q++) = *(p++);
                        continue;
                }

                /* now p[3] is surely valid and is no terminator */

                /* numerical entity */
                if (p[1] == '#') {
                        next = &p[2];
                        if (process_numeric_entity(&next, &code) == FAILURE)
                                goto invalid_code;

                        /* If we're in htmlspecialchars_decode, we're only decoding entities
                         * that represent &, <, >, " and '. Is this one of them? */
                        if (!all && (code > 63U ||
                                        stage3_table_be_apos_00000[code].data.ent.entity == NULL))
                                goto invalid_code;

                        /* are we allowed to decode this entity in this document type?
                         * HTML 5 is the only that has a character that cannot be used in 
                         * a numeric entity but is allowed literally (U+000D). The
                         * unoptimized version would be ... || !numeric_entity_is_allowed(code) */
                        if (!unicode_cp_is_allowed(code, doctype) ||
                                        (doctype == ENT_HTML_DOC_HTML5 && code == 0x0D))
                                goto invalid_code;
                } else {
                        const char *start;
                        size_t ent_len;

                        next = &p[1];
                        start = next;

                        if (process_named_entity_html(&next, &start, &ent_len) == FAILURE)
                                goto invalid_code;

                        if (resolve_named_entity_html(start, ent_len, inv_map, &code, &code2) == FAILURE) {
                                if (doctype == ENT_HTML_DOC_XHTML && ent_len == 4 && start[0] == 'a'
                                                        && start[1] == 'p' && start[2] == 'o' && start[3] == 's') {
                                        /* uses html4 inv_map, which doesn't include apos;. This is a
                                         * hack to support it */
                                        code = (unsigned) '\'';
                                } else {
                                        goto invalid_code;
                                }
                        }
                }
                
                assert(*next == ';');
                
                if (((code == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) ||
                                (code == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE)))
                                /* && code2 == '\0' always true for current maps */)
                        goto invalid_code;

                /* UTF-8 doesn't need mapping (ISO-8859-1 doesn't either, but
                 * the call is needed to ensure the codepoint <= U+00FF)  */
                if (charset != cs_utf_8) {
                        /* replace unicode code point */
                        if (map_from_unicode(code, charset, &code) == FAILURE || code2 != 0)
                                goto invalid_code; /* not representable in target charset */
                }

                q += write_octet_sequence(q, charset, code);
                if (code2) {
                        q += write_octet_sequence(q, charset, code2);
                }

                /* jump over the valid entity; may go beyond size of buffer; np */
                p = next + 1;
                continue;

invalid_code:
                for (; p < next; p++) {
                        *(q++) = *p;
                }
        }
        
        *q = '\0';
        *retlen = (size_t)(q - ret);
}
/* }}} */

/* {{{ unescape_inverse_map */
static const entity_ht *unescape_inverse_map(int all, int flags)
{
        int document_type = flags & ENT_HTML_DOC_TYPE_MASK;

        if (all) {
                switch (document_type) {
                case ENT_HTML_DOC_HTML401:
                case ENT_HTML_DOC_XHTML: /* but watch out for &apos;...*/
                        return &ent_ht_html4;
                case ENT_HTML_DOC_HTML5:
                        return &ent_ht_html5;
                default:
                        return &ent_ht_be_apos;
                }
        } else {
                switch (document_type) {
                case ENT_HTML_DOC_HTML401:
                        return &ent_ht_be_noapos;
                default:
                        return &ent_ht_be_apos;
                }
        }
}
/* }}} */

/* {{{ determine_entity_table
 * Entity table to use. Note that entity tables are defined in terms of
 * unicode code points */
static entity_table_opt determine_entity_table(int all, int doctype)
{
        entity_table_opt retval = {NULL};

        assert(!(doctype == ENT_HTML_DOC_XML1 && all));
        
        if (all) {
                retval.ms_table = (doctype == ENT_HTML_DOC_HTML5) ?
                        entity_ms_table_html5 : entity_ms_table_html4;
        } else {
                retval.table = (doctype == ENT_HTML_DOC_HTML401) ?
                        stage3_table_be_noapos_00000 : stage3_table_be_apos_00000;
        }
        return retval;
}
/* }}} */

/* {{{ php_unescape_html_entities
 * The parameter "all" should be true to decode all possible entities, false to decode
 * only the basic ones, i.e., those in basic_entities_ex + the numeric entities
 * that correspond to quotes.
 */
PHPAPI char *php_unescape_html_entities(unsigned char *old, size_t oldlen, size_t *newlen, int all, int flags, char *hint_charset TSRMLS_DC)
{
        size_t retlen;
        char *ret;
        enum entity_charset charset;
        const entity_ht *inverse_map = NULL;
        size_t new_size = TRAVERSE_FOR_ENTITIES_EXPAND_SIZE(oldlen);

        if (all) {
                charset = determine_charset(hint_charset TSRMLS_CC);
        } else {
                charset = cs_8859_1; /* charset shouldn't matter, use ISO-8859-1 for performance */
        }

        /* don't use LIMIT_ALL! */

        if (oldlen > new_size) {
                /* overflow, refuse to do anything */
                ret = estrndup((char*)old, oldlen);
                retlen = oldlen;
                goto empty_source;
        }
        ret = emalloc(new_size);
        *ret = '\0';
        retlen = oldlen;
        if (retlen == 0) {
                goto empty_source;
        }
        
        inverse_map = unescape_inverse_map(all, flags);
        
        /* replace numeric entities */
        traverse_for_entities(old, oldlen, ret, &retlen, all, flags, inverse_map, charset);

empty_source:   
        *newlen = retlen;
        return ret;
}
/* }}} */

PHPAPI char *php_escape_html_entities(unsigned char *old, size_t oldlen, size_t *newlen, int all, int flags, char *hint_charset TSRMLS_DC)
{
        return php_escape_html_entities_ex(old, oldlen, newlen, all, flags, hint_charset, 1 TSRMLS_CC);
}

/* {{{ find_entity_for_char */
static inline void find_entity_for_char(
        unsigned int k,
        enum entity_charset charset,
        const entity_stage1_row *table,
        const unsigned char **entity,
        size_t *entity_len,
        unsigned char *old,
        size_t oldlen,
        size_t *cursor)
{
        unsigned stage1_idx = ENT_STAGE1_INDEX(k);
        const entity_stage3_row *c;
        
        if (stage1_idx > 0x1D) {
                *entity     = NULL;
                *entity_len = 0;
                return;
        }

        c = &table[stage1_idx][ENT_STAGE2_INDEX(k)][ENT_STAGE3_INDEX(k)];

        if (!c->ambiguous) {
                *entity     = (const unsigned char *)c->data.ent.entity;
                *entity_len = c->data.ent.entity_len;
        } else {
                /* peek at next char */
                size_t   cursor_before  = *cursor;
                int              status                 = SUCCESS;
                unsigned next_char;

                if (!(*cursor < oldlen))
                        goto no_suitable_2nd;

                next_char = get_next_char(charset, old, oldlen, cursor, &status); 

                if (status == FAILURE)
                        goto no_suitable_2nd;

                {
                        const entity_multicodepoint_row *s, *e;

                        s = &c->data.multicodepoint_table[1];
                        e = s - 1 + c->data.multicodepoint_table[0].leading_entry.size;
                        /* we could do a binary search but it's not worth it since we have
                         * at most two entries... */
                        for ( ; s <= e; s++) {
                                if (s->normal_entry.second_cp == next_char) {
                                        *entity     = s->normal_entry.entity;
                                        *entity_len = s->normal_entry.entity_len;
                                        return;
                                }
                        }
                }
no_suitable_2nd:
                *cursor = cursor_before;
                *entity = (const unsigned char *)
                        c->data.multicodepoint_table[0].leading_entry.default_entity;
                *entity_len = c->data.multicodepoint_table[0].leading_entry.default_entity_len;
        }       
}
/* }}} */

/* {{{ find_entity_for_char_basic */
static inline void find_entity_for_char_basic(
        unsigned int k,
        const entity_stage3_row *table,
        const unsigned char **entity,
        size_t *entity_len)
{
        if (k >= 64U) {
                *entity     = NULL;
                *entity_len = 0;
                return;
        }

        *entity     = table[k].data.ent.entity;
        *entity_len = table[k].data.ent.entity_len;
}
/* }}} */

/* {{{ php_escape_html_entities
 */
PHPAPI char *php_escape_html_entities_ex(unsigned char *old, size_t oldlen, size_t *newlen, int all, int flags, char *hint_charset, zend_bool double_encode TSRMLS_DC)
{
        size_t cursor, maxlen, len;
        char *replaced;
        enum entity_charset charset = determine_charset(hint_charset TSRMLS_CC);
        int doctype = flags & ENT_HTML_DOC_TYPE_MASK;
        entity_table_opt entity_table;
        const enc_to_uni *to_uni_table = NULL;
        const entity_ht *inv_map = NULL; /* used for !double_encode */
        /* only used if flags includes ENT_HTML_IGNORE_ERRORS or ENT_HTML_SUBSTITUTE_DISALLOWED_CHARS */
        const unsigned char *replacement = NULL;
        size_t replacement_len = 0;

        if (all) { /* replace with all named entities */
                if (CHARSET_PARTIAL_SUPPORT(charset)) {
                        php_error_docref0(NULL TSRMLS_CC, E_STRICT, "Only basic entities "
                                "substitution is supported for multi-byte encodings other than UTF-8; "
                                "functionality is equivalent to htmlspecialchars");
                }
                LIMIT_ALL(all, doctype, charset);
        }
        entity_table = determine_entity_table(all, doctype);
        if (all && !CHARSET_UNICODE_COMPAT(charset)) {
                to_uni_table = enc_to_uni_index[charset];
        }

        if (!double_encode) {
                /* first arg is 1 because we want to identify valid named entities
                 * even if we are only encoding the basic ones */
                inv_map = unescape_inverse_map(1, flags);
        }

        if (flags & (ENT_HTML_SUBSTITUTE_ERRORS | ENT_HTML_SUBSTITUTE_DISALLOWED_CHARS)) {
                if (charset == cs_utf_8) {
                        replacement = (const unsigned char*)"\xEF\xBF\xBD";
                        replacement_len = sizeof("\xEF\xBF\xBD") - 1;
                } else {
                        replacement = (const unsigned char*)"&#xFFFD;";
                        replacement_len = sizeof("&#xFFFD;") - 1;
                }
        }

        /* initial estimate */
        if (oldlen < 64) {
                maxlen = 128;   
        } else {
                maxlen = 2 * oldlen;
                if (maxlen < oldlen) {
                        zend_error_noreturn(E_ERROR, "Input string is too long");
                        return NULL;
                }
        }

        replaced = emalloc(maxlen + 1); /* adding 1 is safe: maxlen is even */
        len = 0;
        cursor = 0;
        while (cursor < oldlen) {
                const unsigned char *mbsequence = NULL;
                size_t mbseqlen                                 = 0,
                       cursor_before                    = cursor;
                int status                                              = SUCCESS;
                unsigned int this_char                  = get_next_char(charset, old, oldlen, &cursor, &status);

                /* guarantee we have at least 40 bytes to write.
                 * In HTML5, entities may take up to 33 bytes */
                if (len > maxlen - 40) { /* maxlen can never be smaller than 128 */
                        replaced = safe_erealloc(replaced, maxlen , 1, 128 + 1);
                        maxlen += 128;
                }

                if (status == FAILURE) {
                        /* invalid MB sequence */
                        if (flags & ENT_HTML_IGNORE_ERRORS) {
                                continue;
                        } else if (flags & ENT_HTML_SUBSTITUTE_ERRORS) {
                                memcpy(&replaced[len], replacement, replacement_len);
                                len += replacement_len;
                                continue;
                        } else {
                                efree(replaced);
                                *newlen = 0;
                                return STR_EMPTY_ALLOC();
                        }
                } else { /* SUCCESS */
                        mbsequence = &old[cursor_before];
                        mbseqlen = cursor - cursor_before;
                }

                if (this_char != '&') { /* no entity on this position */
                        const unsigned char *rep        = NULL;
                        size_t                          rep_len = 0;

                        if (((this_char == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) ||
                                        (this_char == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE))))
                                goto pass_char_through;

                        if (all) { /* false that CHARSET_PARTIAL_SUPPORT(charset) */
                                if (to_uni_table != NULL) {
                                        /* !CHARSET_UNICODE_COMPAT therefore not UTF-8; since UTF-8
                                         * is the only multibyte encoding with !CHARSET_PARTIAL_SUPPORT,
                                         * we're using a single byte encoding */
                                        map_to_unicode(this_char, to_uni_table, &this_char);
                                        if (this_char == 0xFFFF) /* no mapping; pass through */
                                                goto pass_char_through;
                                }
                                /* the cursor may advance */
                                find_entity_for_char(this_char, charset, entity_table.ms_table, &rep,
                                        &rep_len, old, oldlen, &cursor);
                        } else {
                                find_entity_for_char_basic(this_char, entity_table.table, &rep, &rep_len);
                        }

                        if (rep != NULL) {
                                replaced[len++] = '&';
                                memcpy(&replaced[len], rep, rep_len);
                                len += rep_len;
                                replaced[len++] = ';';
                        } else {
                                /* we did not find an entity for this char.
                                 * check for its validity, if its valid pass it unchanged */
                                if (flags & ENT_HTML_SUBSTITUTE_DISALLOWED_CHARS) {
                                        if (CHARSET_UNICODE_COMPAT(charset)) {
                                                if (!unicode_cp_is_allowed(this_char, doctype)) {
                                                        mbsequence = replacement;
                                                        mbseqlen = replacement_len;
                                                }
                                        } else if (to_uni_table) {
                                                if (!all) /* otherwise we already did this */
                                                        map_to_unicode(this_char, to_uni_table, &this_char);
                                                if (!unicode_cp_is_allowed(this_char, doctype)) {
                                                        mbsequence = replacement;
                                                        mbseqlen = replacement_len;
                                                }
                                        } else {
                                                /* not a unicode code point, unless, coincidentally, it's in
                                                 * the 0x20..0x7D range (except 0x5C in sjis). We know nothing
                                                 * about other code points, because we have no tables. Since
                                                 * Unicode code points in that range are not disallowed in any
                                                 * document type, we could do nothing. However, conversion
                                                 * tables frequently map 0x00-0x1F to the respective C0 code
                                                 * points. Let's play it safe and admit that's the case */
                                                if (this_char <= 0x7D &&
                                                                !unicode_cp_is_allowed(this_char, doctype)) {
                                                        mbsequence = replacement;
                                                        mbseqlen = replacement_len;
                                                }
                                        }
                                }
pass_char_through:
                                if (mbseqlen > 1) {
                                        memcpy(replaced + len, mbsequence, mbseqlen);
                                        len += mbseqlen;
                                } else {
                                        replaced[len++] = mbsequence[0];
                                }
                        }
                } else { /* this_char == '&' */
                        if (double_encode) {
encode_amp:
                                memcpy(&replaced[len], "&amp;", sizeof("&amp;") - 1);
                                len += sizeof("&amp;") - 1;
                        } else { /* no double encode */
                                /* check if entity is valid */
                                size_t ent_len; /* not counting & or ; */
                                /* peek at next char */
                                if (old[cursor] == '#') { /* numeric entity */
                                        unsigned code_point;
                                        int valid;
                                        char *pos = (char*)&old[cursor+1];
                                        valid = process_numeric_entity((const char **)&pos, &code_point);
                                        if (valid == FAILURE)
                                                goto encode_amp;
                                        if (flags & ENT_HTML_SUBSTITUTE_DISALLOWED_CHARS) {
                                                if (!numeric_entity_is_allowed(code_point, doctype))
                                                        goto encode_amp;
                                        }
                                        ent_len = pos - (char*)&old[cursor];
                                } else { /* named entity */
                                        /* check for vality of named entity */
                                        const char *start = &old[cursor],
                                                           *next = start;
                                        unsigned   dummy1, dummy2;

                                        if (process_named_entity_html(&next, &start, &ent_len) == FAILURE)
                                                goto encode_amp;
                                        if (resolve_named_entity_html(start, ent_len, inv_map, &dummy1, &dummy2) == FAILURE) {
                                                if (!(doctype == ENT_HTML_DOC_XHTML && ent_len == 4 && start[0] == 'a'
                                                                        && start[1] == 'p' && start[2] == 'o' && start[3] == 's')) {
                                                        /* uses html4 inv_map, which doesn't include apos;. This is a
                                                         * hack to support it */
                                                        goto encode_amp;
                                                }
                                        }
                                }
                                /* checks passed; copy entity to result */
                                /* entity size is unbounded, we may need more memory */
                                /* at this point maxlen - len >= 40 */
                                if (maxlen - len < ent_len + 2 /* & and ; */) {
                                        /* ent_len < oldlen, which is certainly <= SIZE_MAX/2 */
                                        replaced = safe_erealloc(replaced, maxlen, 1, ent_len + 128 + 1);
                                        maxlen += ent_len + 128;
                                }
                                replaced[len++] = '&';
                                memcpy(&replaced[len], &old[cursor], ent_len);
                                len += ent_len;
                                replaced[len++] = ';';
                                cursor += ent_len + 1;
                        }
                }
        }
        replaced[len] = '\0';
        *newlen = len;

        return replaced;
}
/* }}} */

/* {{{ php_html_entities
 */
static void php_html_entities(INTERNAL_FUNCTION_PARAMETERS, int all)
{
        char *str, *hint_charset = NULL;
        int str_len, hint_charset_len = 0;
        size_t new_len;
        long flags = ENT_COMPAT;
        char *replaced;
        zend_bool double_encode = 1;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|ls!b", &str, &str_len, &flags, &hint_charset, &hint_charset_len, &double_encode) == FAILURE) {
                return;
        }

        replaced = php_escape_html_entities_ex(str, str_len, &new_len, all, (int) flags, hint_charset, double_encode TSRMLS_CC);
        RETVAL_STRINGL(replaced, (int)new_len, 0);
}
/* }}} */

#define HTML_SPECIALCHARS       0
#define HTML_ENTITIES           1

/* {{{ register_html_constants
 */
void register_html_constants(INIT_FUNC_ARGS)
{
        REGISTER_LONG_CONSTANT("HTML_SPECIALCHARS", HTML_SPECIALCHARS, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("HTML_ENTITIES", HTML_ENTITIES, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_COMPAT", ENT_COMPAT, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_QUOTES", ENT_QUOTES, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_NOQUOTES", ENT_NOQUOTES, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_IGNORE", ENT_IGNORE, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_SUBSTITUTE", ENT_SUBSTITUTE, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_DISALLOWED", ENT_DISALLOWED, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_HTML401", ENT_HTML401, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_XML1", ENT_XML1, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_XHTML", ENT_XHTML, CONST_PERSISTENT|CONST_CS);
        REGISTER_LONG_CONSTANT("ENT_HTML5", ENT_HTML5, CONST_PERSISTENT|CONST_CS);
}
/* }}} */

/* {{{ proto string htmlspecialchars(string string [, int quote_style[, string charset[, bool double_encode]]])
   Convert special characters to HTML entities */
PHP_FUNCTION(htmlspecialchars)
{
        php_html_entities(INTERNAL_FUNCTION_PARAM_PASSTHRU, 0);
}
/* }}} */

/* {{{ proto string htmlspecialchars_decode(string string [, int quote_style])
   Convert special HTML entities back to characters */
PHP_FUNCTION(htmlspecialchars_decode)
{
        char *str;
        int str_len;
        size_t new_len = 0;
        long quote_style = ENT_COMPAT;
        char *replaced;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|l", &str, &str_len, &quote_style) == FAILURE) {
                return;
        }

        replaced = php_unescape_html_entities(str, str_len, &new_len, 0 /*!all*/, quote_style, NULL TSRMLS_CC);
        if (replaced) {
                RETURN_STRINGL(replaced, (int)new_len, 0);
        }
        RETURN_FALSE;
}
/* }}} */

/* {{{ proto string html_entity_decode(string string [, int quote_style][, string charset])
   Convert all HTML entities to their applicable characters */
PHP_FUNCTION(html_entity_decode)
{
        char *str, *hint_charset = NULL;
        int str_len, hint_charset_len = 0;
        size_t new_len = 0;
        long quote_style = ENT_COMPAT;
        char *replaced;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|ls", &str, &str_len,
                                                          &quote_style, &hint_charset, &hint_charset_len) == FAILURE) {
                return;
        }

        replaced = php_unescape_html_entities(str, str_len, &new_len, 1 /*all*/, quote_style, hint_charset TSRMLS_CC);
        if (replaced) {
                RETURN_STRINGL(replaced, (int)new_len, 0);
        }
        RETURN_FALSE;
}
/* }}} */


/* {{{ proto string htmlentities(string string [, int quote_style[, string charset[, bool double_encode]]])
   Convert all applicable characters to HTML entities */
PHP_FUNCTION(htmlentities)
{
        php_html_entities(INTERNAL_FUNCTION_PARAM_PASSTHRU, 1);
}
/* }}} */

/* {{{ write_s3row_data */
static inline void write_s3row_data(
        const entity_stage3_row *r,
        unsigned orig_cp,
        enum entity_charset charset,
        zval *arr)
{
        char key[9] = ""; /* two unicode code points in UTF-8 */
        char entity[LONGEST_ENTITY_LENGTH + 2] = {'&'};
        size_t written_k1;

        written_k1 = write_octet_sequence(key, charset, orig_cp);

        if (!r->ambiguous) {
                size_t l = r->data.ent.entity_len;
                memcpy(&entity[1], r->data.ent.entity, l);
                entity[l + 1] = ';';
                add_assoc_stringl_ex(arr, key, written_k1 + 1, entity, l + 2, 1);
        } else {
                unsigned i,
                             num_entries;
                const entity_multicodepoint_row *mcpr = r->data.multicodepoint_table;

                if (mcpr[0].leading_entry.default_entity != NULL) {
                        size_t l = mcpr[0].leading_entry.default_entity_len;
                        memcpy(&entity[1], mcpr[0].leading_entry.default_entity, l);
                        entity[l + 1] = ';';
                        add_assoc_stringl_ex(arr, key, written_k1 + 1, entity, l + 2, 1);
                }
                num_entries = mcpr[0].leading_entry.size;
                for (i = 1; i <= num_entries; i++) {
                        size_t   l,
                                     written_k2;
                        unsigned uni_cp,
                                         spe_cp;

                        uni_cp = mcpr[i].normal_entry.second_cp;
                        l = mcpr[i].normal_entry.entity_len;

                        if (!CHARSET_UNICODE_COMPAT(charset)) {
                                if (map_from_unicode(uni_cp, charset, &spe_cp) == FAILURE)
                                        continue; /* non representable in this charset */
                        } else {
                                spe_cp = uni_cp;
                        }
                        
                        written_k2 = write_octet_sequence(&key[written_k1], charset, spe_cp);
                        memcpy(&entity[1], mcpr[i].normal_entry.entity, l);
                        entity[l + 1] = ';';
                        entity[l + 1] = '\0';
                        add_assoc_stringl_ex(arr, key, written_k1 + written_k2 + 1, entity, l + 1, 1);
                }
        }
}
/* }}} */

/* {{{ proto array get_html_translation_table([int table [, int flags [, string charset_hint]]])
   Returns the internal translation table used by htmlspecialchars and htmlentities */
PHP_FUNCTION(get_html_translation_table)
{
        long all = HTML_SPECIALCHARS,
                 flags = ENT_COMPAT;
        int doctype;
        entity_table_opt entity_table;
        const enc_to_uni *to_uni_table = NULL;
        char *charset_hint = NULL;
        int charset_hint_len;
        enum entity_charset charset;

        /* in this function we have to jump through some loops because we're
         * getting the translated table from data structures that are optimized for
         * random access, not traversal */

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|lls",
                        &all, &flags, &charset_hint, &charset_hint_len) == FAILURE) {
                return;
        }

        charset = determine_charset(charset_hint TSRMLS_CC);
        doctype = flags & ENT_HTML_DOC_TYPE_MASK;
        LIMIT_ALL(all, doctype, charset);

        array_init(return_value);
        
        entity_table = determine_entity_table(all, doctype);
        if (all && !CHARSET_UNICODE_COMPAT(charset)) {
                to_uni_table = enc_to_uni_index[charset];
        }

        if (all) { /* HTML_ENTITIES (actually, any non-zero value for 1st param) */
                const entity_stage1_row *ms_table = entity_table.ms_table;

                if (CHARSET_UNICODE_COMPAT(charset)) {
                        unsigned i, j, k,
                                         max_i, max_j, max_k;
                        /* no mapping to unicode required */
                        if (CHARSET_SINGLE_BYTE(charset)) { /* ISO-8859-1 */
                                max_i = 1; max_j = 4; max_k = 64;
                        } else {
                                max_i = 0x1E; max_j = 64; max_k = 64;
                        }

                        for (i = 0; i < max_i; i++) {
                                if (ms_table[i] == empty_stage2_table)
                                        continue;
                                for (j = 0; j < max_j; j++) {
                                        if (ms_table[i][j] == empty_stage3_table)
                                                continue;
                                        for (k = 0; k < max_k; k++) {
                                                const entity_stage3_row *r = &ms_table[i][j][k];
                                                unsigned code;

                                                if (r->data.ent.entity == NULL)
                                                        continue;

                                                code = ENT_CODE_POINT_FROM_STAGES(i, j, k);
                                                if (((code == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) ||
                                                                (code == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE))))
                                                        continue;
                                                write_s3row_data(r, code, charset, return_value);
                                        }
                                }
                        }
                } else {
                        /* we have to iterate through the set of code points for this
                         * encoding and map them to unicode code points */
                        unsigned i;
                        for (i = 0; i <= 0xFF; i++) {
                                const entity_stage3_row *r;
                                unsigned uni_cp;

                                /* can be done before mapping, they're invariant */
                                if (((i == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) ||
                                                (i == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE))))
                                        continue;

                                map_to_unicode(i, to_uni_table, &uni_cp);
                                r = &ms_table[ENT_STAGE1_INDEX(uni_cp)][ENT_STAGE2_INDEX(uni_cp)][ENT_STAGE3_INDEX(uni_cp)];
                                if (r->data.ent.entity == NULL)
                                        continue;

                                write_s3row_data(r, i, charset, return_value);
                        }
                }
        } else {
                /* we could use sizeof(stage3_table_be_apos_00000) as well */
                unsigned          j,
                                          numelems = sizeof(stage3_table_be_noapos_00000) /
                                                        sizeof(*stage3_table_be_noapos_00000);

                for (j = 0; j < numelems; j++) {
                        const entity_stage3_row *r = &entity_table.table[j];
                        if (r->data.ent.entity == NULL)
                                continue;

                        if (((j == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) ||
                                        (j == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE))))
                                continue;

                        /* charset is indifferent, used cs_8859_1 for efficiency */
                        write_s3row_data(r, j, cs_8859_1, return_value);
                }
        }
}
/* }}} */

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: sw=4 ts=4 fdm=marker
 * vim<600: sw=4 ts=4
 */

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