fix: unpacking tarballs that contain hard links (#7062)

.changeset/modern-wombats-tease.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/store.cafs": patch
+"pnpm": patch
+---
+
+Tarballs that have hard links are now unpacked successfully. This fixes a regression introduced in v8.7.0, which was shipped with our new in-house tarball parser [#7062](https://github.com/pnpm/pnpm/pull/7062).

store/cafs/src/parseTarball.ts

@@ -12,6 +12,7 @@ export interface IFile {
 }
 
 const ZERO: number = '0'.charCodeAt(0)
+const FILE_TYPE_HARD_LINK: number = '1'.charCodeAt(0)
 const FILE_TYPE_SYMLINK: number = '2'.charCodeAt(0)
 const FILE_TYPE_DIRECTORY: number = '5'.charCodeAt(0)
 const SPACE: number = ' '.charCodeAt(0)
@@ -135,6 +136,7 @@ export function parseTarball (buffer: Buffer): IParseResult {
     switch (fileType) {
     case 0:
     case ZERO:
+    case FILE_TYPE_HARD_LINK:
       // The file mode is an octal number encoded as UTF-8. It is terminated by a NUL or space. Maximum length 8 characters.
       mode = parseOctal(blockStart + MODE_OFFSET, 8)
 

store/cafs/test/index.ts

@@ -113,3 +113,12 @@ test('unpack an older version of tar that prefixes with spaces', () => {
     'package.json',
   ])
 })
+
+test('unpack a tarball that contains hard links', () => {
+  const dest = tempy.directory()
+  const cafs = createCafs(dest)
+  const { filesIndex } = cafs.addFilesFromTarball(
+    fs.readFileSync(path.join(__dirname, 'fixtures/vue.examples.todomvc.todo-store-0.0.1.tgz'))
+  )
+  expect(Object.keys(filesIndex).length).toBeGreaterThan(0)
+})