--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hoedown/src/autolink.c	Wed Feb 24 20:54:52 2016 +0100
@@ -0,0 +1,281 @@
+#include "autolink.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#ifndef _MSC_VER
+#include <strings.h>
+#else
+#define strncasecmp	_strnicmp
+#endif
+
+int
+hoedown_autolink_is_safe(const uint8_t *data, size_t size)
+{
+	static const size_t valid_uris_count = 6;
+	static const char *valid_uris[] = {
+		"http://", "https://", "/", "#", "ftp://", "mailto:"
+	};
+	static const size_t valid_uris_size[] = { 7, 8, 1, 1, 6, 7 };
+	size_t i;
+
+	for (i = 0; i < valid_uris_count; ++i) {
+		size_t len = valid_uris_size[i];
+
+		if (size > len &&
+			strncasecmp((char *)data, valid_uris[i], len) == 0 &&
+			isalnum(data[len]))
+			return 1;
+	}
+
+	return 0;
+}
+
+static size_t
+autolink_delim(uint8_t *data, size_t link_end, size_t max_rewind, size_t size)
+{
+	uint8_t cclose, copen = 0;
+	size_t i;
+
+	for (i = 0; i < link_end; ++i)
+		if (data[i] == '<') {
+			link_end = i;
+			break;
+		}
+
+	while (link_end > 0) {
+		if (strchr("?!.,:", data[link_end - 1]) != NULL)
+			link_end--;
+
+		else if (data[link_end - 1] == ';') {
+			size_t new_end = link_end - 2;
+
+			while (new_end > 0 && isalpha(data[new_end]))
+				new_end--;
+
+			if (new_end < link_end - 2 && data[new_end] == '&')
+				link_end = new_end;
+			else
+				link_end--;
+		}
+		else break;
+	}
+
+	if (link_end == 0)
+		return 0;
+
+	cclose = data[link_end - 1];
+
+	switch (cclose) {
+	case '"':	copen = '"'; break;
+	case '\'':	copen = '\''; break;
+	case ')':	copen = '('; break;
+	case ']':	copen = '['; break;
+	case '}':	copen = '{'; break;
+	}
+
+	if (copen != 0) {
+		size_t closing = 0;
+		size_t opening = 0;
+		size_t i = 0;
+
+		/* Try to close the final punctuation sign in this same line;
+		 * if we managed to close it outside of the URL, that means that it's
+		 * not part of the URL. If it closes inside the URL, that means it
+		 * is part of the URL.
+		 *
+		 * Examples:
+		 *
+		 *	foo http://www.pokemon.com/Pikachu_(Electric) bar
+		 *		=> http://www.pokemon.com/Pikachu_(Electric)
+		 *
+		 *	foo (http://www.pokemon.com/Pikachu_(Electric)) bar
+		 *		=> http://www.pokemon.com/Pikachu_(Electric)
+		 *
+		 *	foo http://www.pokemon.com/Pikachu_(Electric)) bar
+		 *		=> http://www.pokemon.com/Pikachu_(Electric))
+		 *
+		 *	(foo http://www.pokemon.com/Pikachu_(Electric)) bar
+		 *		=> foo http://www.pokemon.com/Pikachu_(Electric)
+		 */
+
+		while (i < link_end) {
+			if (data[i] == copen)
+				opening++;
+			else if (data[i] == cclose)
+				closing++;
+
+			i++;
+		}
+
+		if (closing != opening)
+			link_end--;
+	}
+
+	return link_end;
+}
+
+static size_t
+check_domain(uint8_t *data, size_t size, int allow_short)
+{
+	size_t i, np = 0;
+
+	if (!isalnum(data[0]))
+		return 0;
+
+	for (i = 1; i < size - 1; ++i) {
+		if (strchr(".:", data[i]) != NULL) np++;
+		else if (!isalnum(data[i]) && data[i] != '-') break;
+	}
+
+	if (allow_short) {
+		/* We don't need a valid domain in the strict sense (with
+		 * least one dot; so just make sure it's composed of valid
+		 * domain characters and return the length of the the valid
+		 * sequence. */
+		return i;
+	} else {
+		/* a valid domain needs to have at least a dot.
+		 * that's as far as we get */
+		return np ? i : 0;
+	}
+}
+
+size_t
+hoedown_autolink__www(
+	size_t *rewind_p,
+	hoedown_buffer *link,
+	uint8_t *data,
+	size_t max_rewind,
+	size_t size,
+	unsigned int flags)
+{
+	size_t link_end;
+
+	if (max_rewind > 0 && !ispunct(data[-1]) && !isspace(data[-1]))
+		return 0;
+
+	if (size < 4 || memcmp(data, "www.", strlen("www.")) != 0)
+		return 0;
+
+	link_end = check_domain(data, size, 0);
+
+	if (link_end == 0)
+		return 0;
+
+	while (link_end < size && !isspace(data[link_end]))
+		link_end++;
+
+	link_end = autolink_delim(data, link_end, max_rewind, size);
+
+	if (link_end == 0)
+		return 0;
+
+	hoedown_buffer_put(link, data, link_end);
+	*rewind_p = 0;
+
+	return (int)link_end;
+}
+
+size_t
+hoedown_autolink__email(
+	size_t *rewind_p,
+	hoedown_buffer *link,
+	uint8_t *data,
+	size_t max_rewind,
+	size_t size,
+	unsigned int flags)
+{
+	size_t link_end, rewind;
+	int nb = 0, np = 0;
+
+	for (rewind = 0; rewind < max_rewind; ++rewind) {
+		uint8_t c = data[-1 - rewind];
+
+		if (isalnum(c))
+			continue;
+
+		if (strchr(".+-_", c) != NULL)
+			continue;
+
+		break;
+	}
+
+	if (rewind == 0)
+		return 0;
+
+	for (link_end = 0; link_end < size; ++link_end) {
+		uint8_t c = data[link_end];
+
+		if (isalnum(c))
+			continue;
+
+		if (c == '@')
+			nb++;
+		else if (c == '.' && link_end < size - 1)
+			np++;
+		else if (c != '-' && c != '_')
+			break;
+	}
+
+	if (link_end < 2 || nb != 1 || np == 0 ||
+		!isalpha(data[link_end - 1]))
+		return 0;
+
+	link_end = autolink_delim(data, link_end, max_rewind, size);
+
+	if (link_end == 0)
+		return 0;
+
+	hoedown_buffer_put(link, data - rewind, link_end + rewind);
+	*rewind_p = rewind;
+
+	return link_end;
+}
+
+size_t
+hoedown_autolink__url(
+	size_t *rewind_p,
+	hoedown_buffer *link,
+	uint8_t *data,
+	size_t max_rewind,
+	size_t size,
+	unsigned int flags)
+{
+	size_t link_end, rewind = 0, domain_len;
+
+	if (size < 4 || data[1] != '/' || data[2] != '/')
+		return 0;
+
+	while (rewind < max_rewind && isalpha(data[-1 - rewind]))
+		rewind++;
+
+	if (!hoedown_autolink_is_safe(data - rewind, size + rewind))
+		return 0;
+
+	link_end = strlen("://");
+
+	domain_len = check_domain(
+		data + link_end,
+		size - link_end,
+		flags & HOEDOWN_AUTOLINK_SHORT_DOMAINS);
+
+	if (domain_len == 0)
+		return 0;
+
+	link_end += domain_len;
+	while (link_end < size && !isspace(data[link_end]))
+		link_end++;
+
+	link_end = autolink_delim(data, link_end, max_rewind, size);
+
+	if (link_end == 0)
+		return 0;
+
+	hoedown_buffer_put(link, data - rewind, link_end + rewind);
+	*rewind_p = rewind;
+
+	return link_end;
+}