From 8af820e60e777ed4318a198091c25474ae81d816 Mon Sep 17 00:00:00 2001
From: Aziz Rmadi <46684200+armadi1809@users.noreply.github.com>
Date: Thu, 30 Jan 2025 23:21:51 -0600
Subject: [PATCH] fixed write header bug in case of errors in index html
 (#4185)

---
 webserver/handlers/index.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/webserver/handlers/index.go b/webserver/handlers/index.go
index fb75c2982..dc4419333 100644
--- a/webserver/handlers/index.go
+++ b/webserver/handlers/index.go
@@ -108,9 +108,15 @@ func renderIndexHtml(w http.ResponseWriter, nonce string) {
 		return
 	}
 
-	if err := index.Execute(w, content); err != nil {
+	// Use a buffer to ensure that we do not write a partial response header before checking for errors
+	var buf bytes.Buffer
+	if err := index.Execute(&buf, content); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
 	}
+
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write(buf.Bytes())
 }
 
 // MetadataPage represents a server-rendered web page for bots and web scrapers.