From 015f590298406585e66b2afe01a2da13c3fcf04c Mon Sep 17 00:00:00 2001
From: PlumBlossomMaid <108660099+PlumBlossomMaid@users.noreply.github.com>
Date: Sun, 12 Apr 2026 03:57:13 +0800
Subject: [PATCH] Prevent sending headers if already sent

---
 lua/express/misc/finalhandler.lua | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lua/express/misc/finalhandler.lua b/lua/express/misc/finalhandler.lua
index 6c6697b..c314d68 100644
--- a/lua/express/misc/finalhandler.lua
+++ b/lua/express/misc/finalhandler.lua
@@ -32,6 +32,9 @@ local createHtmlDocument = function(message)
 end
 
 local send = function(req, res, status, headers, msg)
+    if res.pg_res._headersSended then
+        return
+    end
 	local body = createHtmlDocument(msg)
 
 	if status then