Add FileSystemEntity.absolutePath and .isAbsolute properties.

sdk/lib/io/link.dart

 // Copyright (c) 2013, 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;
 
 /**
  * [Link] objects are references to filesystem links.
  *
  */
@@ skipping 67 matching lines @@
    * Synchronously renames this link. Returns a [Link]
    * instance for the renamed link.
    *
    * If [newPath] identifies an existing link, that link is
    * replaced. If [newPath] identifies an existing file or directory
    * the operation fails and an exception is thrown.
    */
   Link renameSync(String newPath);
 
   /**
+   * Returns a [Link] instance whose path is the absolute path to [this].
+   *
+   * The absolute path is computed by prefixing
+   * a relative path with the current working directory, and returning
+   * an absolute path unchanged.
+   */
+  Link get absolute;
+
+  /**
    * Gets the target of the link. Returns a future that completes with
    * the path to the target.
    *
    * If the returned target is a relative path, it is relative to the
    * directory containing the link.
    *
    * If the link does not exist, or is not a link, the future completes with
    * a LinkException.
    */
   Future<String> target();
@@ skipping 22 matching lines @@
     }
   }
 
 
   String toString() => "Link: '$path'";
 
   Future<bool> exists() => FileSystemEntity.isLink(path);
 
   bool existsSync() => FileSystemEntity.isLinkSync(path);
 
+  Link get absolute => new Link(_absolutePath);
+
   Future<FileStat> stat() => FileStat.stat(path);
 
   FileStat statSync() => FileStat.statSync(path);
 
   Future<Link> create(String target) {
     _ensureFileService();
     if (Platform.operatingSystem == 'windows') {
       target = _makeWindowsLinkTarget(target);
     }
     List request = new List(3);
@@ skipping 173 matching lines @@
       if (path != null) {
         sb.write(", path = $path");
       }
     }
     return sb.toString();
   }
   final String message;
   final String path;
   final OSError osError;
 }