fix(extract-stream): compensate for bug in tar-fs chowning

lib/extract-stream.js

@@ -1,20 +1,65 @@
 'use strict'
 
+var chownr = require('chownr')
 var gunzip = require('./util/gunzip-maybe')
 var path = require('path')
 var pipeline = require('mississippi').pipeline
 var tar = require('tar-fs')
+var to = require('mississippi').to
 
 module.exports = extractStream
 function extractStream (dest, opts) {
   opts = opts || {}
+  var errEmitted = false
+  var tarStream = makeTarStream(dest, opts)
+  var target = to(function (chunk, enc, cb) {
+    tarStream.write(chunk, enc, cb)
+  }, function flush (cb) {
+    // TODO - there's a bug in tar-fs so we have to do this manually.
+    //        This code ms.to() stunt can be removed afer the issue is fixed:
+    //        https://github.com/mafintosh/tar-fs/issues/59
+    tarStream.end(function () {
+      if (
+        process.platform !== 'win32' &&
+        process.getuid &&
+        process.getuid() === 0 &&
+        (typeof opts.uid === 'number' || typeof opts.gid === 'number')
+      ) {
+        chownr(
+          dest,
+          typeof opts.uid === 'number' ? opts.uid : process.getuid(),
+          typeof opts.gid === 'number' ? opts.gid : process.getgid(),
+          cb
+        )
+      } else {
+        cb()
+      }
+    })
+  })
+  target.on('error', function (err) {
+    if (!errEmitted) {
+      errEmitted = true
+      tarStream.emit('error', err)
+    }
+  })
+  tarStream.on('error', function (err) {
+    if (!errEmitted) {
+      errEmitted = true
+      target.emit('error', err)
+    }
+  })
+  return target
+}
+
+function makeTarStream (dest, opts) {
   var sawIgnores = {}
   return pipeline(gunzip(), tar.extract(dest, {
     map: function (header) {
-      if (process.platform !== 'win32') {
+      if (process.getuid && process.getuid() === 0) {
         header.uid = opts.uid == null ? header.uid : opts.uid
         header.gid = opts.gid == null ? header.gid : opts.gid
       }
+
       // Note: This mirrors logic in the fs read operations that are
       // employed during tarball creation, in the fstream-npm module.
       // It is duplicated here to handle tarballs that are created