From 9c655ac75dd78c909b1f713d72d85da043c57673 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCrg=C3=BCn=20Day=C4=B1o=C4=9Flu?= <hey@gurgun.day>
Date: Fri, 24 Oct 2025 23:03:32 +0200
Subject: [PATCH] buffer: add early return for zero-length concat calls

---
 benchmark/buffers/buffer-concat.js | 2 +-
 lib/buffer.js                      | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/benchmark/buffers/buffer-concat.js b/benchmark/buffers/buffer-concat.js
index 26edc649d8d349..51704978872940 100644
--- a/benchmark/buffers/buffer-concat.js
+++ b/benchmark/buffers/buffer-concat.js
@@ -3,7 +3,7 @@ const common = require('../common.js');
 
 const bench = common.createBenchmark(main, {
   pieces: [4, 16],
-  pieceSize: [1, 16, 256],
+  pieceSize: [0, 1, 16, 256],
   withTotalLength: [0, 1],
   n: [8e5],
 });
diff --git a/lib/buffer.js b/lib/buffer.js
index c9f45d333886d3..3148a6b4e4d9d3 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -590,6 +590,9 @@ Buffer.concat = function concat(list, length) {
     validateOffset(length, 'length');
   }
 
+  if (length === 0)
+    return new FastBuffer();
+
   const buffer = Buffer.allocUnsafe(length);
   let pos = 0;
   for (let i = 0; i < list.length; i++) {