nodejs/node

Version

v26.12.1

Platform

win32 x64 v26.12.1

Subsystem

vfs

What steps will reproduce the bug?

1. Create a ZIP archive containing two directories with conflicting filenames.

Save the following as zip-rename-repro.mjs:

import { ZipEntry, ZipBuffer, createZipArchive } from 'node:zlib'; import { ZipProvider, create } from 'node:vfs';

const entries = await Promise.all([ ZipEntry.create('src/file.txt', Buffer.from('Original A')), ZipEntry.create('dst/file.txt', Buffer.from('Original B')), ZipEntry.create('dst/keep.txt', Buffer.from('Keep this file')) ]);

const archive = Buffer.concat( await Array.fromAsync(createZipArchive(entries)) );

const zip = new ZipBuffer(archive); const fs = create(new ZipProvider(zip));

console.log('Before:', fs.readFileSync('/dst/file.txt', 'utf8'));

try { fs.renameSync('/src', '/dst'); console.log('Rename succeeded despite nonempty destination'); } catch (error) { console.log('Rename failed:', error.code); }

console.log('After:', fs.readFileSync('/dst/file.txt', 'utf8'));

2. Run it using:

node --experimental-vfs .\zip-rename-repro.mjs

3. Observe that the existing destination file is silently overwritten.

4. Additional reproduction: persistent data loss after failure