From d921a2b1443876ab701059460f34d8eb0ffe1e1d Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Fri, 11 Oct 2024 16:54:56 -0400
Subject: [PATCH] Escape LF in board file, refuse to store or print control
 chars

---
 internal/bulb/bulb.ha | 49 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 39 insertions(+), 10 deletions(-)

diff --git a/internal/bulb/bulb.ha b/internal/bulb/bulb.ha
index 805016e..2ab0fe1 100644
--- a/internal/bulb/bulb.ha
+++ b/internal/bulb/bulb.ha
@@ -1,3 +1,4 @@
+use ascii;
 use bufio;
 use fs;
 use fmt;
@@ -40,8 +41,37 @@ export fn read(output: io::handle, board: str, number: int) (void | error) = {
 	// we add 1 to account for the blank line that will always be at the
 	// bottom
 	seek_to_nth_last_line(file, number + 1)?;
-	// TODO don't copy control characters!
-	io::copy(output, file)?;
+	
+	static let output_wbuf: [os::BUFSZ]u8 = [0...];
+	let output = bufio::init(output, [], output_wbuf);
+	let file   = bufio::newscanner(file);
+	defer bufio::finish(&file);
+
+	let saw_escape = false;
+	for (true) {
+		let byte = match (bufio::scan_byte(&file)?) {
+		case let byte: u8 => yield byte;
+		case io::EOF      => break;
+		};
+
+		if (byte == '\x1b') {
+			saw_escape = true;
+		} else {
+			if (byte == '\n') {
+				if (saw_escape) {
+					fmt::fprint(&output, "\n  ")?;
+				} else {
+					fmt::fprint(&output, "\n")?;
+				};
+			} else if (!ascii::iscntrl(byte: rune)) {
+				let fake_buffer: [1]u8 = [byte];
+				io::write(&output, fake_buffer)?;
+			};
+			saw_escape = false;
+		};
+	};
+	
+	bufio::flush(&output)?;
 };
 
 export fn post(input: io::handle, board: str, user_name: (str | void)) (void | error) = {
@@ -56,27 +86,26 @@ export fn post(input: io::handle, board: str, user_name: (str | void)) (void | e
 	};
 
 	static let file_wbuf: [os::BUFSZ]u8 = [0...];
-	let file = bufio::init(file, [], file_wbuf);
-	let scanner = bufio::newscanner(input);
-	defer bufio::finish(&scanner);
+	let file  = bufio::init(file, [], file_wbuf);
+	let input = bufio::newscanner(input);
+	defer bufio::finish(&input);
 
 	let saw_break = false;
 	fmt::fprintf(&file, "{}: ", user)?;
 	for (true) {
-		let byte = match (bufio::scan_byte(&scanner)?) {
+		let byte = match (bufio::scan_byte(&input)?) {
 		case let byte: u8 => yield byte;
 		case io::EOF      => break;
 		};
 		
 		if (saw_break) {
-			fmt::fprint(&file, "\n  ")?;
+			fmt::fprint(&file, "\x1b\n")?;
 			saw_break = false;
 		};
 
-		switch (byte) {
-		case '\n' =>
+		if (byte == '\n') {
 			saw_break = true;
-		case =>
+		} else if (!ascii::iscntrl(byte: rune)) {
 			let fake_buffer: [1]u8 = [byte];
 			io::write(&file, fake_buffer)?;
 		};