From 0f239307dbe6f4520eb7715529c595eedba0b050 Mon Sep 17 00:00:00 2001
From: Roderik van der Veer <roderik@settlemint.com>
Date: Thu, 25 Nov 2021 14:56:46 +0100
Subject: [PATCH] backport
 https://github.com/http-party/node-http-proxy/pull/1552

---
 lib/http-proxy/passes/ws-incoming.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/http-proxy/passes/ws-incoming.js b/lib/http-proxy/passes/ws-incoming.js
index 270f23f45..e5787f297 100644
--- a/lib/http-proxy/passes/ws-incoming.js
+++ b/lib/http-proxy/passes/ws-incoming.js
@@ -111,7 +111,7 @@ module.exports = {
     proxyReq.on('error', onOutgoingError);
     proxyReq.on('response', function (res) {
       // if upgrade event isn't going to happen, close the socket
-      if (!res.upgrade) {
+      if (!res.upgrade && socket.readyState !== "closed") {
         socket.write(createHttpHeader('HTTP/' + res.httpVersion + ' ' + res.statusCode + ' ' + res.statusMessage, res.headers));
         res.pipe(socket);
       }