New Uri.parse and validation.

sdk/lib/io/http_impl.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;
 
 const int _OUTGOING_BUFFER_SIZE = 8 * 1024;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
@@ skipping 1656 matching lines @@
                                            String host,
                                            int port)) {
     _badCertificateCallback = callback;
   }
 
 
   Future<HttpClientRequest> open(String method,
                                  String host,
                                  int port,
                                  String path) {
+    Uri uri = new Uri(scheme: "http", host: host, port: port).resolve(path);
     // TODO(sgjesse): The path set here can contain both query and
     // fragment. They should be cracked and set correctly.
-    return _openUrl(method, new Uri(
-        scheme: "http", host: host, port: port, path: path));
+    return _openUrl(method, uri);
   }
 
   Future<HttpClientRequest> openUrl(String method, Uri url) {
     return _openUrl(method, url);
   }
 
   Future<HttpClientRequest> get(String host, int port, String path)
       => open("get", host, port, path);
 
   Future<HttpClientRequest> getUrl(Uri url) => _openUrl("get", url);
@@ skipping 1107 matching lines @@
   const _RedirectInfo(this.statusCode, this.method, this.location);
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }