From e8b7b50f8607dc63704787ce07c066c8c385ff15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=BDiga=20Kokelj?= <ziga.kokelj@gmail.com>
Date: Wed, 22 Nov 2023 10:54:51 +0100
Subject: [PATCH] Prevent concurrent writes to a websocket connection (#1656)

---
 tools/walletextension/userconn/user_conn.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/walletextension/userconn/user_conn.go b/tools/walletextension/userconn/user_conn.go
index e9bbc640ff..4acb9ebf2f 100644
--- a/tools/walletextension/userconn/user_conn.go
+++ b/tools/walletextension/userconn/user_conn.go
@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
+	"sync"
 
 	"github.com/ten-protocol/go-ten/go/common/log"
 
@@ -39,6 +40,7 @@ type userConnWS struct {
 	isClosed bool
 	logger   gethlog.Logger
 	req      *http.Request
+	mu       sync.Mutex
 }
 
 func NewUserConnHTTP(resp http.ResponseWriter, req *http.Request, logger gethlog.Logger) UserConn {
@@ -106,6 +108,9 @@ func (w *userConnWS) ReadRequest() ([]byte, error) {
 }
 
 func (w *userConnWS) WriteResponse(msg []byte) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
 	err := w.conn.WriteMessage(websocket.TextMessage, msg)
 	if err != nil {
 		if websocket.IsCloseError(err) || strings.Contains(string(msg), "EOF") {