From 960e5db2fefa1a3d5a7469ddd7f88f1fabfd174a Mon Sep 17 00:00:00 2001
From: Claude Bot <claude-bot@bun.sh>
Date: Fri, 16 Jan 2026 18:15:20 +0000
Subject: [PATCH] fix: use hasContentLen instead of hasContentLength for header
 removal

Use the post-headers flag (hasContentLen) that reflects the effective
headers after writeHead() obj headers are applied, rather than the
initial hasContentLength value.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 src/js/node/_http_server.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/js/node/_http_server.ts b/src/js/node/_http_server.ts
index d45cc321e3..dedd786ab9 100644
--- a/src/js/node/_http_server.ts
+++ b/src/js/node/_http_server.ts
@@ -1187,7 +1187,8 @@ function _writeHead(statusCode, reason, obj, response) {
       // Trailers cannot be used without chunked encoding
       if (response.hasHeader("trailer")) {
         // If "Trailer" header is explicitly set, that's an error
-        if (hasContentLength) {
+        // Use hasContentLen (not hasContentLength) to reflect current headers after obj applied
+        if (hasContentLen) {
           response.removeHeader("trailer");
         } else {
           response.removeHeader("content-length");