fix: don't panic on short errors

0x416e746f6e · 0x416e746f6e · commit 3c264de1e072 · 2025-07-12T17:22:05.000+02:00
diff --git a/proxy/websocket.go b/proxy/websocket.go
@@ -392,10 +392,15 @@ func (p *Websocket) closeWebsocket(conn *websocket.Conn, reason error) error {
 		)
 	}
 
+	msg := []byte(reason.Error())
+	if len(msg) > 125 {
+		// maxControlFramePayloadSize == 125
+		msg = msg[:125]
+	}
+
 	return errors.Join(
 		conn.WriteControl(
-			// maxControlFramePayloadSize == 125
-			websocket.CloseMessage, []byte(reason.Error())[:125], utils.Deadline(p.cfg.proxy.ControlTimeout),
+			websocket.CloseMessage, msg, utils.Deadline(p.cfg.proxy.ControlTimeout),
 		),
 		conn.Close(),
 	)

Original file line number	Diff line number	Diff line change
`@@ -392,10 +392,15 @@ func (p Websocket) closeWebsocket(conn websocket.Conn, reason error) error {`
`392`	`392`	`)`
`393`	`393`	`}`
`394`	`394`
	`395`	`+ msg := []byte(reason.Error())`
	`396`	`+ if len(msg) > 125 {`
	`397`	`+ // maxControlFramePayloadSize == 125`
	`398`	`+ msg = msg[:125]`
	`399`	`+ }`
	`400`	`+`
`395`	`401`	`return errors.Join(`
`396`	`402`	`conn.WriteControl(`
`397`		`- // maxControlFramePayloadSize == 125`
`398`		`- websocket.CloseMessage, []byte(reason.Error())[:125], utils.Deadline(p.cfg.proxy.ControlTimeout),`
	`403`	`+ websocket.CloseMessage, msg, utils.Deadline(p.cfg.proxy.ControlTimeout),`
`399`	`404`	`),`
`400`	`405`	`conn.Close(),`
`401`	`406`	`)`