From fc48dfc0a557b6a66178b074907010f72a4b6a53 Mon Sep 17 00:00:00 2001
From: luca0N! <luca0n@luca0n.com>
Date: Wed, 30 Mar 2022 15:19:03 -0300
Subject: [PATCH] Ignore markdown when reading HTML comments

---
 src/MarkdownParser.cxx | 56 ++++++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/src/MarkdownParser.cxx b/src/MarkdownParser.cxx
index ea633a2..8d19a2b 100644
--- a/src/MarkdownParser.cxx
+++ b/src/MarkdownParser.cxx
@@ -81,17 +81,19 @@ std::string make_html(std::filesystem::path const &path) {
 	     tag_li = false,
 	     tag_ul = false,
 		 tag_s = false,
+		 tag_comment = false,
 	     newline = true,
 	     manualBreak = false,
 	     // Used to ignore spaces at the beginning of header titles.
 	     ignoreSpace = false;
+	unsigned short char_skip = 0;
 
 	// For counting sub-headers (h1, h2, h3, and so on)
 	int tag_h = 0;
 	while (fgets(buf, buflen, mdFile) != NULL) {
 		manualBreak = false;
 
-		if (tag_p && buf[0] == '\n') {
+		if (!tag_comment && tag_p && buf[0] == '\n') {
 			// Empty newline; end paragraph.
 			html += "</p>\n";
 			tag_p = false;
@@ -107,9 +109,13 @@ std::string make_html(std::filesystem::path const &path) {
 
 		// Read character by character
 		for (int x = 0; x < buflen; x++) {
+			if (char_skip > 0) {
+					char_skip--;
+					continue;
+			}
 			char c = buf[x];
 			if (c == '\0') break;
-			else if (c == '\n') {
+			else if (!tag_comment && c == '\n') {
 				// The next buffer iteration will hold the
 				// first (buflen) bytes of the next new line.
 				newline = true;
@@ -131,16 +137,27 @@ std::string make_html(std::filesystem::path const &path) {
 			// Start paragraph if newline and no
 			// special characters were matched.
 
-			if (!tag_p && newline && x == 0 &&
-					c != '#' && c != '-')
+			if (!tag_comment && (!tag_p && newline && x == 0 &&
+					c != '#' && c != '-'))
 				html += "<p>",
 				     tag_p = true;
 
 			switch (c) {
+				case '<':
+						// Check for HTML comment
+						if (buf[x+1] == '!' &&
+							buf[x+2] == '-' &&
+							buf[x+3] == '-')
+								char_skip = 3,
+								tag_comment = true,
+								html += "<!--";
+						else
+								append(c);
+						break;
 				case '*':
 					// Bold check
 					// Check whether this character has been escaped.
-					if (buf[x-1] == '\\') {
+					if (tag_comment || buf[x-1] == '\\') {
 						append(&c);
 						break;
 					}
@@ -153,7 +170,7 @@ std::string make_html(std::filesystem::path const &path) {
 					// Check whether this character has
 					// been escaped.
 					
-					if (buf[x-1] == '\\') {
+					if (tag_comment || buf[x-1] == '\\') {
 						append(&c);
 						break;
 					}
@@ -167,7 +184,7 @@ std::string make_html(std::filesystem::path const &path) {
 					// Headers must be declared at the
 					// beginning of a new line. Ignore it
 					// if this is not a new line.
-					if (!newline) {
+					if (tag_comment || !newline) {
 						append(&c);
 						break;
 					}
@@ -213,11 +230,10 @@ std::string make_html(std::filesystem::path const &path) {
 						ignoreSpace = true;
 						break;
 					}
-
 					break;
 				case '~':
 					// Escape character
-					if (x > 0 && buf[x-1] == '\\') {
+					if (tag_comment || (x > 0 && buf[x-1] == '\\')) {
 						append(c);
 						break;
 					}
@@ -230,8 +246,16 @@ std::string make_html(std::filesystem::path const &path) {
 					append(c);
 					break;
 				case '-':
-					if (x != 0) {
-						append('-');
+					if (tag_comment &&
+						buf[x+1] == '-' &&
+						buf[x+2] == '>') {
+							tag_comment = false,
+							html += "-->",
+							char_skip = 2;
+							continue;
+					}
+					if (tag_comment || x != 0) {
+						append(c);
 						break;
 					}
 
@@ -243,7 +267,7 @@ std::string make_html(std::filesystem::path const &path) {
 					break;
 				case '[':
 					// Hyperlink text declaration has begun
-					if (tag_a != NONE) {
+					if (tag_comment || tag_a != NONE) {
 						// Cannot add hyperlinks inside of hyperlinks;
 						append(&c);
 						break;
@@ -254,7 +278,7 @@ std::string make_html(std::filesystem::path const &path) {
 					break;
 				case ']':
 					// Hyperlink text declaration ended
-					if (tag_a != READING_CONTENTS) {
+					if (tag_comment || tag_a != READING_CONTENTS) {
 						// Ignore if not reading hyperlink.
 						append(&c);
 						break;
@@ -263,7 +287,7 @@ std::string make_html(std::filesystem::path const &path) {
 					break;
 				case '(':
 					// Hyperlink address declaration has begun
-					if (tag_a != EXPECTING_URL) {
+					if (tag_comment || tag_a != EXPECTING_URL) {
 						append(&c);
 						break;
 					}
@@ -271,7 +295,7 @@ std::string make_html(std::filesystem::path const &path) {
 					break;
 				case ')':
 					// Hyperlink address declaration ended
-					if (tag_a != READING_URL) {
+					if (tag_comment || tag_a != READING_URL) {
 						append(&c);
 						break;
 					}
@@ -283,7 +307,7 @@ std::string make_html(std::filesystem::path const &path) {
 					append("</a>");
 					break;
 				case ' ':
-					if (ignoreSpace) {
+					if (!tag_comment && ignoreSpace) {
 						ignoreSpace = false;
 						break;
 					} else append(" ");