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- #include <assert.h>
- #include <stdio.h>
- #include <string.h>
- #include "buffer.h"
- #include "houdini.h"
- #include "utf8.h"
- #include "entities.inc"
- /* Binary tree lookup code for entities added by JGM */
- static const unsigned char *S_lookup(int i, int low, int hi,
- const unsigned char *s, int len) {
- int j;
- int cmp =
- strncmp((const char *)s, (const char *)cmark_entities[i].entity, len);
- if (cmp == 0 && cmark_entities[i].entity[len] == 0) {
- return (const unsigned char *)cmark_entities[i].bytes;
- } else if (cmp <= 0 && i > low) {
- j = i - ((i - low) / 2);
- if (j == i)
- j -= 1;
- return S_lookup(j, low, i - 1, s, len);
- } else if (cmp > 0 && i < hi) {
- j = i + ((hi - i) / 2);
- if (j == i)
- j += 1;
- return S_lookup(j, i + 1, hi, s, len);
- } else {
- return NULL;
- }
- }
- static const unsigned char *S_lookup_entity(const unsigned char *s, int len) {
- return S_lookup(CMARK_NUM_ENTITIES / 2, 0, CMARK_NUM_ENTITIES - 1, s, len);
- }
- bufsize_t houdini_unescape_ent(cmark_strbuf *ob, const uint8_t *src,
- bufsize_t size) {
- bufsize_t i = 0;
- if (size >= 3 && src[0] == '#') {
- int codepoint = 0;
- int num_digits = 0;
- if (_isdigit(src[1])) {
- for (i = 1; i < size && _isdigit(src[i]); ++i) {
- codepoint = (codepoint * 10) + (src[i] - '0');
- if (codepoint >= 0x110000) {
- // Keep counting digits but
- // avoid integer overflow.
- codepoint = 0x110000;
- }
- }
- num_digits = i - 1;
- }
- else if (src[1] == 'x' || src[1] == 'X') {
- for (i = 2; i < size && _isxdigit(src[i]); ++i) {
- codepoint = (codepoint * 16) + ((src[i] | 32) % 39 - 9);
- if (codepoint >= 0x110000) {
- // Keep counting digits but
- // avoid integer overflow.
- codepoint = 0x110000;
- }
- }
- num_digits = i - 2;
- }
- if (num_digits >= 1 && num_digits <= 8 && i < size && src[i] == ';') {
- if (codepoint == 0 || (codepoint >= 0xD800 && codepoint < 0xE000) ||
- codepoint >= 0x110000) {
- codepoint = 0xFFFD;
- }
- cmark_utf8proc_encode_char(codepoint, ob);
- return i + 1;
- }
- }
- else {
- if (size > CMARK_ENTITY_MAX_LENGTH)
- size = CMARK_ENTITY_MAX_LENGTH;
- for (i = CMARK_ENTITY_MIN_LENGTH; i < size; ++i) {
- if (src[i] == ' ')
- break;
- if (src[i] == ';') {
- const unsigned char *entity = S_lookup_entity(src, i);
- if (entity != NULL) {
- cmark_strbuf_puts(ob, (const char *)entity);
- return i + 1;
- }
- break;
- }
- }
- }
- return 0;
- }
- int houdini_unescape_html(cmark_strbuf *ob, const uint8_t *src,
- bufsize_t size) {
- bufsize_t i = 0, org, ent;
- while (i < size) {
- org = i;
- while (i < size && src[i] != '&')
- i++;
- if (likely(i > org)) {
- if (unlikely(org == 0)) {
- if (i >= size)
- return 0;
- cmark_strbuf_grow(ob, HOUDINI_UNESCAPED_SIZE(size));
- }
- cmark_strbuf_put(ob, src + org, i - org);
- }
- /* escaping */
- if (i >= size)
- break;
- i++;
- ent = houdini_unescape_ent(ob, src + i, size - i);
- i += ent;
- /* not really an entity */
- if (ent == 0)
- cmark_strbuf_putc(ob, '&');
- }
- return 1;
- }
- void houdini_unescape_html_f(cmark_strbuf *ob, const uint8_t *src,
- bufsize_t size) {
- if (!houdini_unescape_html(ob, src, size))
- cmark_strbuf_put(ob, src, size);
- }
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