Work around issue 4928.

utils/tests/pub/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:io';
 
 import 'package:pathos/path.dart' as path;
 import 'package:unittest/unittest.dart';
@@ skipping 101 matching lines @@
       expect(withTempDir((temp) {
         writeTextFile(path.join(temp, 'file1.txt'), '');
         createSymlink(temp, path.join(temp, 'linkdir'));
 
         expect(listDir(temp, recursive: true), unorderedEquals([
           path.join(temp, 'file1.txt'),
           path.join(temp, 'linkdir')
         ]));
       }), completes);
     });
+
+    test('treats a broken symlink as a file', () {
+      expect(withTempDir((temp) {
+        writeTextFile(path.join(temp, 'file1.txt'), '');
+        createDir(path.join(temp, 'dir'));
+        createSymlink(path.join(temp, 'dir'), path.join(temp, 'linkdir'));
+        deleteEntry(path.join(temp, 'dir'));
+
+        expect(listDir(temp, recursive: true), unorderedEquals([
+          path.join(temp, 'file1.txt'),
+          path.join(temp, 'linkdir')
+        ]));
+      }), completes);
+    });
   });
 
   testExistencePredicate("entryExists", entryExists,
       forFile: true,
       forFileSymlink: true,
       forMultiLevelFileSymlink: true,
       forDirectory: true,
       forDirectorySymlink: true,
       forMultiLevelDirectorySymlink: true,
       forBrokenSymlink: true,
@@ skipping 125 matching lines @@
           var symlink2Path = path.join(temp, "link2.txt");
           writeTextFile(targetPath, "contents");
           createSymlink(targetPath, symlink1Path);
           createSymlink(symlink1Path, symlink2Path);
           expect(predicate(symlink2Path), equals(forMultiLevelFileSymlink));
         }), completes);
       });
     }
   });
 }