From a5ba28dda2c2ff0eb3201169ad3cf46d960e0c13 Mon Sep 17 00:00:00 2001
From: Brian White <mscdex@mscdex.net>
Date: Sun, 4 Jul 2021 07:14:22 -0400
Subject: [PATCH] stream: fix performance regression

PR-URL: https://github.com/nodejs/node/pull/39254
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/internal/streams/duplex.js | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/lib/internal/streams/duplex.js b/lib/internal/streams/duplex.js
index 3d65c15f201dd7..6916f954ac48c3 100644
--- a/lib/internal/streams/duplex.js
+++ b/lib/internal/streams/duplex.js
@@ -56,19 +56,23 @@ function Duplex(options) {
   Readable.call(this, options);
   Writable.call(this, options);
 
-  this.allowHalfOpen = options?.allowHalfOpen !== false;
+  if (options) {
+    this.allowHalfOpen = options.allowHalfOpen !== false;
 
-  if (options?.readable === false) {
-    this._readableState.readable = false;
-    this._readableState.ended = true;
-    this._readableState.endEmitted = true;
-  }
+    if (options.readable === false) {
+      this._readableState.readable = false;
+      this._readableState.ended = true;
+      this._readableState.endEmitted = true;
+    }
 
-  if (options?.writable === false) {
-    this._writableState.writable = false;
-    this._writableState.ending = true;
-    this._writableState.ended = true;
-    this._writableState.finished = true;
+    if (options.writable === false) {
+      this._writableState.writable = false;
+      this._writableState.ending = true;
+      this._writableState.ended = true;
+      this._writableState.finished = true;
+    }
+  } else {
+    this.allowHalfOpen = true;
   }
 }