0001-Support-array-ish-args-to-Buffer-ctor.patch

From 75d7f34fbee6b7ae4a65d9334c38ebd66de565bb Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Tue, 1 Feb 2011 00:06:44 -0800
Subject: [PATCH] Support array-ish args to Buffer ctor

Any array-ish thing (whether a Buffer, an Array, or just an object with
a numeric "length") is interpreted as a list of bytes.
---
 lib/buffer.js              |   10 ++++++++--
 test/simple/test-buffer.js |    8 ++++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/lib/buffer.js b/lib/buffer.js
index 2733947..7369807 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -139,8 +139,8 @@ function Buffer(subject, encoding, offset) {
       pool.used += this.length;
     }
 
-    // Assume object is an array
-    if (Array.isArray(subject)) {
+    // Treat array-ish objects as a byte array.
+    if (isArrayIsh(subject)) {
       for (var i = 0; i < this.length; i++) {
         this.parent[i + this.offset] = subject[i];
       }
@@ -153,6 +153,12 @@ function Buffer(subject, encoding, offset) {
   SlowBuffer.makeFastBuffer(this.parent, this, this.offset, this.length);
 }
 
+function isArrayIsh(subject) {
+  return Array.isArray(subject) || Buffer.isBuffer(subject) ||
+         subject && typeof subject === 'object' &&
+         typeof subject.length === 'number';
+}
+
 exports.SlowBuffer = SlowBuffer;
 exports.Buffer = Buffer;
 
diff --git a/test/simple/test-buffer.js b/test/simple/test-buffer.js
index e8756a7..2e7b990 100644
--- a/test/simple/test-buffer.js
+++ b/test/simple/test-buffer.js
@@ -216,6 +216,7 @@ assert.equal(d.length, 3);
 assert.equal(d[0], 23);
 assert.equal(d[1], 42);
 assert.equal(d[2], 255);
+assert.deepEqual(d, new Buffer(d));
 
 var e = new Buffer('über');
 console.error('uber: \'%s\'', e.toString());
@@ -225,6 +226,13 @@ var f = new Buffer('über', 'ascii');
 console.error('f.length: %d     (should be 4)', f.length);
 assert.deepEqual(f, new Buffer([252, 98, 101, 114]));
 
+var arrayIsh = {0: 0, 1: 1, 2: 2, 3: 3, length: 4};
+var g = new Buffer(arrayIsh);
+assert.deepEqual(g, new Buffer([0, 1, 2, 3]));
+var strArrayIsh = {0: '0', 1: '1', 2: '2', 3: '3', length: 4};
+g = new Buffer(strArrayIsh);
+assert.deepEqual(g, new Buffer([0, 1, 2, 3]));
+
 
 //
 // Test toString('base64')
-- 
1.7.2.3