buffer: fix creating from zero-length ArrayBuffer

RReverser · addaleax · commit 0e9e149da431 · 2016-06-13T17:10:33.000+02:00
Fixes regression where creating a new Buffer from an empty ArrayBuffer would fail. Ref: nodejs@85ab4a5 PR-URL: nodejs#7176 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com> Reviewed-By: Ron Korving <ron@ronkorving.nl>
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -257,7 +257,7 @@ function fromArrayBuffer(obj, byteOffset, length) {
 
   const maxLength = obj.byteLength - byteOffset;
 
-  if (maxLength <= 0)
+  if (maxLength < 0)
     throw new RangeError("'offset' is out of bounds");
 
   if (length === undefined) {
diff --git a/test/parallel/test-buffer-alloc.js b/test/parallel/test-buffer-alloc.js
@@ -1459,3 +1459,8 @@ const ubuf = Buffer.allocUnsafeSlow(10);
 assert(ubuf);
 assert(ubuf.buffer);
 assert.equal(ubuf.buffer.byteLength, 10);
+
+// Regression test
+assert.doesNotThrow(() => {
+  Buffer.from(new ArrayBuffer());
+});
