Make sure to check for OS errors when constructing Uri.base

runtime/bin/builtin.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 builtin;
 import 'dart:async';
 import 'dart:convert';
 import 'dart:isolate';
 
 
@@ skipping 94 matching lines @@
 void _print(arg) {
   _Logger._printString(arg.toString());
 }
 
 class _Logger {
   static void _printString(String s) native "Logger_PrintString";
 }
 
 _getPrintClosure() => _print;
 
-_getCurrentDirectoryPath() native "Directory_Current";
-
 // Corelib 'Uri.base' implementation.
 Uri _uriBase() {

[Søren Gjesse, 2015/03/04 12:48:13]

We could also do this, if we care about not allocating one Directory object in
this case. I don't think we need to.

  // We are not using Dircetory.current here to avoid allocating a
  // Directory object.
  var result = _getCurrentDirectoryPath();
  if (result is OSError) {
    throw new FileSystemException(
        "Getting current working directory failed", "", result);
  }
  return new Uri.file(result + "/");

[Ivan Posva, 2015/03/04 17:36:25]

By using Directory.current you need to import "dart:io" which we have the goal
to remove. So please use the alternate code. Thanks!

-  return new Uri.file(_getCurrentDirectoryPath() + "/");
+  return new Uri.file(Directory.current.path + "/");
 }
 
 _getUriBaseClosure() => _uriBase;
 
 
 // Are we running on Windows?
 var _isWindows;
 var _workingWindowsDrivePrefix;
 // The current working directory
 var _workingDirectoryUri;
@@ skipping 336 matching lines @@
   } else {
     name = userUri.substring(index + 1);
     path = userUri.substring(0, index + 1);
   }
 
   path = _filePathFromUri(path);
   var filename = _platformExtensionFileName(name);
 
   return [path, filename, name];
 }