Don't send null data events on a Socket stream.

sdk/lib/io/secure_socket.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;
 
 /**
  * A high-level class for communicating securely over a TCP socket, using
  * TLS and SSL. The [SecureSocket] exposes both a [Stream] and an
  * [IOSink] interface, making it ideal for using together with
@@ skipping 393 matching lines @@
         new Timer(0, (_) => _readHandler());
       }
     }
   }
 
   List<int> read([int len]) {
     if (_closedRead) {
       throw new SocketIOException("Reading from a closed socket");
     }
     if (_status != CONNECTED) {
-      return new List<int>(0);
+      return null;
     }
     var buffer = _secureFilter.buffers[READ_PLAINTEXT];
     _readEncryptedData();
     int toRead = buffer.length;
     if (len != null) {
       if (len is! int || len < 0) {
         throw new ArgumentError(
             "Invalid len parameter in SecureSocket.read (len: $len)");
       }
       if (len < toRead) {
@@ skipping 313 matching lines @@
   void destroy();
   void handshake();
   void init();
   X509Certificate get peerCertificate;
   int processBuffer(int bufferIndex);
   void registerBadCertificateCallback(Function callback);
   void registerHandshakeCompleteCallback(Function handshakeCompleteHandler);
 
   List<_ExternalBuffer> get buffers;
 }