Fixing markdown licensing && compilation issues.

include/cmark/houdini_html_u.c

@@ -0,0 +1,149 @@
+#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);
+}