Avoid double-// on directory listing.

sdk/lib/io/directory_impl.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.
 
 part of dart.io;
 
 class _Directory implements Directory {
   static const CREATE_REQUEST = 0;
   static const DELETE_REQUEST = 1;
   static const EXISTS_REQUEST = 2;
@@ skipping 219 matching lines @@
     if (_path is !String || newPath is !String) {
       throw new ArgumentError();
     }
     var result = _rename(_path, newPath);
     if (result is OSError) {
       throw new DirectoryException("Rename failed", _path, result);
     }
     return new Directory(newPath);
   }
 
+  static String _trimTrailingPathSeparators(String path) {
+    // Don't handle argument errors here.
+    if (path is! String) return path;
+    if (Platform.operatingSystem == 'windows') {

[Søren Gjesse, 2013/06/18 06:54:09]

Won't this loop work for both Windows and non-Windows?

[Anders Johnsen, 2013/06/18 06:55:26]

Yeah, but it'll be twice as slow.

+      while (path.length > 1 &&
+             (path.endsWith(Platform.pathSeparator) ||
+              path.endsWith('/'))) {
+        path = path.substring(0, path.length - 1);
+      }
+    } else {
+      while (path.length > 1 && path.endsWith(Platform.pathSeparator)) {
+        path = path.substring(0, path.length - 1);
+      }
+    }
+    return path;
+  }
+
   Stream<FileSystemEntity> list({bool recursive: false,
                                  bool followLinks: true}) {
-    return new _AsyncDirectoryLister(path, recursive, followLinks).stream;
+    return new _AsyncDirectoryLister(_trimTrailingPathSeparators(path),
+                                     recursive,
+                                     followLinks).stream;
   }
 
   List listSync({bool recursive: false, bool followLinks: true}) {
-    if (_path is! String || recursive is! bool) {
+    if (_path is! String || recursive is! bool || followLinks is! bool) {
       throw new ArgumentError();
     }
-    return _list(_path, recursive, followLinks);
+    return _list(_trimTrailingPathSeparators(path), recursive, followLinks);
   }
 
   String get path => _path;
 
   String toString() => "Directory: '$path'";
 
   bool _isErrorResponse(response) {
     return response is List && response[0] != _SUCCESS_RESPONSE;
   }
 
@@ skipping 145 matching lines @@
       controller.addError(
           new DirectoryException("Directory listing failed",
                                  errorPath,
                                  err));
     } else {
       controller.addError(
           new DirectoryException("Internal error"));
     }
   }
 }