Pub's listDir shouldn't fail when called within hidden directories.

sdk/lib/_internal/pub/test/io_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library io_test;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
@@ skipping 32 matching lines @@
         expect(listDir(temp, recursive: true, includeHidden: true),
             unorderedEquals([
           path.join(temp, 'file1.txt'),
           path.join(temp, 'file2.txt'),
           path.join(temp, '.file3.txt'),
           path.join(temp, '.subdir'),
           path.join(temp, '.subdir', 'file3.txt')
         ]));
       }), completes);
     });
+
+    test("doesn't ignore hidden files above the directory being listed", () {
+      expect(withTempDir((temp) {
+        var dir = path.join(temp, '.foo', 'bar');
+        ensureDir(dir);
+        writeTextFile(path.join(dir, 'file1.txt'), '');
+        writeTextFile(path.join(dir, 'file2.txt'), '');
+        writeTextFile(path.join(dir, 'file3.txt'), '');
+
+        expect(listDir(dir, recursive: true), unorderedEquals([
+          path.join(dir, 'file1.txt'),
+          path.join(dir, 'file2.txt'),
+          path.join(dir, 'file3.txt')
+        ]));
+      }), completes);
+    });
   });
 
   group('canonicalize', () {
     test('resolves a non-link', () {
       expect(withCanonicalTempDir((temp) {
         var filePath = path.join(temp, 'file');
         writeTextFile(filePath, '');
         expect(canonicalize(filePath), equals(filePath));
       }), completes);
     });
@@ skipping 277 matching lines @@
           expect(predicate(symlink2Path), equals(forMultiLevelFileSymlink));
         }), completes);
       });
     }
   });
 }
 
 /// Like [withTempDir], but canonicalizes the path before passing it to [fn].
 Future withCanonicalTempDir(Future fn(String path)) =>
   withTempDir((temp) => fn(canonicalize(temp)));