Fix bug in HTTP client request generation

runtime/bin/http_parser.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.
 
 // Global constants.
 class _Const {
   // Bytes for "HTTP".
   static const HTTP = const [72, 84, 84, 80];
   // Bytes for "HTTP/1.".
   static const HTTP1DOT = const [72, 84, 84, 80, 47, 49, 46];
@@ skipping 216 matching lines @@
             } else {
               if (_Const.SEPARATORS_AND_CR_LF.indexOf(byte) != -1) {
                 throw new HttpParserException("Invalid request method");
               }
               _method_or_status_code.addCharCode(byte);
             }
             break;
 
           case _State.REQUEST_LINE_URI:
             if (byte == _CharCode.SP) {
+              if (_uri_or_reason_phrase.length == 0) {
+                throw new HttpParserException("Invalid request URI");
+              }
               _state = _State.REQUEST_LINE_HTTP_VERSION;
               _httpVersionIndex = 0;
             } else {
               if (byte == _CharCode.CR || byte == _CharCode.LF) {
                 throw new HttpParserException("Invalid request URI");
               }
               _uri_or_reason_phrase.addCharCode(byte);
             }
             break;
 
@@ skipping 468 matching lines @@
   Function dataEnd;
   Function error;
 }
 
 
 class HttpParserException implements Exception {
   const HttpParserException([String this.message = ""]);
   String toString() => "HttpParserException: $message";
   final String message;
 }