From 819351eab3fc4c2f1d7adc8c3e753312ea83dcc9 Mon Sep 17 00:00:00 2001
From: Wessie <github@wessie.info>
Date: Wed, 24 Jan 2024 12:20:50 +0100
Subject: [PATCH] Fix #63

Logic race condition, if the decode goroutine can run before the caller
can the channel returned might not have a receiver yet and then the
select/default construct will drop the event and close the channel.

The caller then ends up with a zero-value decodedEvent where
decodedEvent.err and decodedEvent.event are both nil which passes the
err check at line 434 and might enter line 440 where decodedEvent.event
is then used as-is with no additional check for it being nil.
---
 conn.go | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/conn.go b/conn.go
index c32eca6..2ae1831 100644
--- a/conn.go
+++ b/conn.go
@@ -150,35 +150,24 @@ type decodedEvent struct {
 }
 
 func (c *ircConn) decode() <-chan decodedEvent {
-	ch := make(chan decodedEvent)
+	ch := make(chan decodedEvent, 1)
 
 	go func() {
 		defer close(ch)
 
 		line, err := c.io.ReadString(delim)
 		if err != nil {
-			select {
-			case ch <- decodedEvent{err: err}:
-			default:
-			}
-
+			ch <- decodedEvent{err: err}
 			return
 		}
 
 		event := ParseEvent(line)
 		if event == nil {
-			select {
-			case ch <- decodedEvent{err: ErrParseEvent{Line: line}}:
-			default:
-			}
-
+			ch <- decodedEvent{err: ErrParseEvent{Line: line}}
 			return
 		}
 
-		select {
-		case ch <- decodedEvent{event: event}:
-		default:
-		}
+		ch <- decodedEvent{event: event}
 	}()
 
 	return ch