buffer: make Buffer work with resizable ArrayBuffer

Fixes: #52195 PR-URL: #55377 Reviewed-By: Robert Nagy <[email protected]> Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: Benjamin Gruenbaum <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: Matteo Collina <[email protected]>

Author: jasnell

lib/buffer.js

@@ -504,9 +504,7 @@ function fromArrayBuffer(obj, byteOffset, length){
 if(maxLength<0)
 thrownewERR_BUFFER_OUT_OF_BOUNDS('offset');
 
-if(length===undefined){
-length=maxLength;
-}else{
+if(length!==undefined){
 // Convert length to non-negative integer.
 length=+length;
 if(length>0){

test/parallel/test-buffer-resizable.js

@@ -0,0 +1,29 @@
+// Flags: --no-warnings
+'use strict';
+
+require('../common');
+const{ Buffer }=require('node:buffer');
+const{ strictEqual }=require('node:assert');
+const{ describe, it }=require('node:test');
+
+describe('Using resizable ArrayBuffer with Buffer...',()=>{
+it('works as expected',()=>{
+constab=newArrayBuffer(10,{maxByteLength: 20});
+constbuffer=Buffer.from(ab,1);
+strictEqual(buffer.byteLength,9);
+ab.resize(15);
+strictEqual(buffer.byteLength,14);
+ab.resize(5);
+strictEqual(buffer.byteLength,4);
+});
+
+it('works with the deprecated constructor also',()=>{
+constab=newArrayBuffer(10,{maxByteLength: 20});
+constbuffer=newBuffer(ab,1);
+strictEqual(buffer.byteLength,9);
+ab.resize(15);
+strictEqual(buffer.byteLength,14);
+ab.resize(5);
+strictEqual(buffer.byteLength,4);
+});
+});