From 371cecdb849875dc40c2d21eb0bd085814c5c30a Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Fri, 3 Apr 2026 12:30:06 -0300
Subject: [PATCH] guard against nil connections on write to protect against
 concurrent listener removals.

---
 khatru/websocket.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/khatru/websocket.go b/khatru/websocket.go
index c5b984e..40484c6 100644
--- a/khatru/websocket.go
+++ b/khatru/websocket.go
@@ -2,6 +2,7 @@ package khatru
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"sync"
 
@@ -31,6 +32,9 @@ type WebSocket struct {
 }
 
 func (ws *WebSocket) WriteJSON(any any) error {
+	if ws == nil {
+		return fmt.Errorf("connection doesn't exist")
+	}
 	ws.mutex.Lock()
 	err := ws.conn.WriteJSON(any)
 	ws.mutex.Unlock()