buffer: fix creating from zero-length ArrayBuffer

Fixes regression where creating a new Buffer from an empty ArrayBuffer would fail. Ref: 85ab4a5 PR-URL: #7176 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Сковорода Никита Андреевич <[email protected]> Reviewed-By: Ron Korving <[email protected]>

Author: RReverser

lib/buffer.js

@@ -218,7 +218,7 @@ function fromArrayBuffer(obj, byteOffset, length){
 
 constmaxLength=obj.byteLength-byteOffset;
 
-if(maxLength<=0)
+if(maxLength<0)
 thrownewRangeError("'offset' is out of bounds");
 
 if(length===undefined){

test/parallel/test-buffer-alloc.js

@@ -1458,3 +1458,8 @@ const ubuf = Buffer.allocUnsafeSlow(10);
 assert(ubuf);
 assert(ubuf.buffer);
 assert.equal(ubuf.buffer.byteLength,10);
+
+// Regression test
+assert.doesNotThrow(()=>{
+Buffer.from(newArrayBuffer());
+});