From 8b5a8cf371f290ffd93c20042b9aa94f7e67ae4f Mon Sep 17 00:00:00 2001
From: Luigi Pinca <luigipinca@gmail.com>
Date: Sat, 2 Sep 2023 17:10:11 +0200
Subject: [PATCH] Do not deadlock on empty chunks

Refs: https://github.com/nodejs/node/issues/29758
Refs: https://github.com/nodejs/node/commit/f58e8eb103ff3087
---
 index.js      |  8 ++++++--
 test/index.js | 22 +++++++++++++++++++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index c0f1459..a5551aa 100644
--- a/index.js
+++ b/index.js
@@ -20,8 +20,12 @@ class DuplexSocket extends Duplex {
   }
 
   _write(chunk, encoding, callback) {
-    this[kOtherSide][kCallback] = callback;
-    this[kOtherSide].push(chunk);
+    if (chunk.length === 0) {
+      process.nextTick(callback);
+    } else {
+      this[kOtherSide].push(chunk);
+      this[kOtherSide][kCallback] = callback;
+    }
   }
 
   _final(callback) {
diff --git a/test/index.js b/test/index.js
index f5b800f..3150524 100644
--- a/test/index.js
+++ b/test/index.js
@@ -4,7 +4,7 @@ const DuplexPair = require('../');
 const assert = require('assert');
 
 describe('DuplexPair', function() {
-  it('passed data through', function() {
+  it('passes data through', function() {
     const pair = new DuplexPair({ encoding: 'utf8' });
     pair.socket1.write('Hello');
     assert.strictEqual(pair.socket1.read(), null);
@@ -18,4 +18,24 @@ describe('DuplexPair', function() {
     pair.socket2.end();
     assert.strictEqual(pair.socket1.read(), null);
   });
+
+  it('does not deadlock when writing empty chunks', function(done) {
+    const pair = new DuplexPair({ encoding: 'utf8' });
+
+    pair.socket2.resume();
+    pair.socket2.on('end', function() {
+      pair.socket2.write('Hello');
+      pair.socket2.write('');
+      pair.socket2.end();
+    });
+
+    pair.socket1.on('data', function(chunk) {
+      assert.strictEqual(chunk, 'Hello');
+    });
+    pair.socket1.on('end', function() {
+      done();
+    });
+
+    pair.socket1.end();
+  });
 });