From 40358d406dec1d08fe0ed3c188db97713a77e41d Mon Sep 17 00:00:00 2001
From: Oliver Gugger <gugger@gmail.com>
Date: Tue, 29 Mar 2022 18:15:43 +0200
Subject: [PATCH] lnrpc: fix websocket proxy data race

Was discovered in a race unit test in lightning node connect that uses
the websocket proxy to connect to the hashmail server on the client
side.
By not shadowing the err variable we end up reading and writing to the
same variable from two different goroutines, which causes the data race.
---
 lnrpc/websocket_proxy.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lnrpc/websocket_proxy.go b/lnrpc/websocket_proxy.go
index 803cf6c36..7aaa9b1f2 100644
--- a/lnrpc/websocket_proxy.go
+++ b/lnrpc/websocket_proxy.go
@@ -253,7 +253,7 @@ func (p *WebsocketProxy) upgradeToWebSocketProxy(w http.ResponseWriter,
 				payload = newPayload
 			}
 
-			_, err = requestForwarder.Write(payload)
+			_, err := requestForwarder.Write(payload)
 			if err != nil {
 				p.logger.Errorf("WS: error writing message "+
 					"to upstream http server: %v", err)
@@ -338,7 +338,7 @@ func (p *WebsocketProxy) upgradeToWebSocketProxy(w http.ResponseWriter,
 			continue
 		}
 
-		err = conn.WriteMessage(
+		err := conn.WriteMessage(
 			websocket.TextMessage, responseForwarder.Bytes(),
 		)
 		if err != nil {