Handle stdio redirection in standalone VM

runtime/bin/socket_impl.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.
 
 
 class _SocketBase {
   // Bit flags used when communicating between the eventhandler and
   // dart code. The EVENT flags are used to indicate events of
   // interest when sending a message from dart code to the
   // eventhandler. When receiving a message from the eventhandler the
@@ skipping 79 matching lines @@
   }
 
   void _getPort() native "Socket_GetPort";
 
   void set errorHandler(void callback()) {
     _setHandler(_ERROR_EVENT, callback);
   }
 
   void _activateHandlers() {
     if (_canActivateHandlers && (_id >= 0)) {
+      if (_handlerMask == 0) {
+        if (_handler != null) {
+          _handler.close();
+          _handler = null;
+        }
+        return;
+      }
       int data = _handlerMask;
       if (_isListenSocket()) {
         data |= (1 << _LISTENING_SOCKET);
       } else {
         if (_closedRead) { data &= ~(1 << _IN_EVENT); }
         if (_closedWrite) { data &= ~(1 << _OUT_EVENT); }
         if (_isPipe()) data |= (1 << _PIPE);
       }
       _sendToEventHandler(data);
     }
@@ skipping 355 matching lines @@
   bool _seenFirstOutEvent = false;
   bool _closedRead = false;
   bool _closedWrite = false;
   bool _pipe = false;
   Function _clientConnectHandler;
   Function _clientWriteHandler;
   SocketInputStream _inputStream;
   SocketOutputStream _outputStream;
 }