Implement redirect-stdout-on-close on Winows, to the 'NUL' device.

runtime/bin/eventhandler_win.cc

 // 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.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/eventhandler.h"
 
 #include <process.h>  // NOLINT
 #include <winsock2.h>  // NOLINT
 #include <ws2tcpip.h>  // NOLINT
 #include <mswsock.h>  // NOLINT
+#include <io.h>  // NOLINT
+#include <fcntl.h>  // NOLINT
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/log.h"
 #include "bin/socket.h"
 #include "bin/utils.h"
 #include "platform/thread.h"
 
 
 namespace dart {
@@ skipping 295 matching lines @@
     CreateCompletionPort(event_handler_->completion_port());
   }
 }
 
 
 bool FileHandle::IsClosed() {
   return false;
 }
 
 
+void FileHandle::DoClose() {
+  if (GetStdHandle(STD_OUTPUT_HANDLE) == handle_) {
+    int fd = _open("NUL", _O_WRONLY);

[kustermann, 2013/06/28 10:10:14]

Is this opening a file called "NUL" or an actual /dev/null-like device?

[Anders Johnsen, 2013/06/28 10:19:11]

Yep, check out http://en.wikipedia.org/wiki/%5CDevice%5CNull

+    ASSERT(fd >= 0);
+    USE(_dup2(fd, _fileno(stdout)));
+    USE(close(fd));

[kustermann, 2013/06/28 10:10:14]

AFAIK USE() is not necessary here.
USE() is useful in cases where you store return values in a variable and don't
use the variable. Ignoring the return value of a function should be fine?!

[Anders Johnsen, 2013/06/28 10:19:11]

I think you are right. Will try without.

+  } else {
+    Handle::DoClose();
+  }
+}
+
+
 void SocketHandle::HandleIssueError() {
   int error = WSAGetLastError();
   if (error == WSAECONNRESET) {
     event_handler_->HandleClosed(this);
   } else {
     event_handler_->HandleError(this);
   }
   WSASetLastError(error);
 }
 
@@ skipping 662 matching lines @@
 
 
 void EventHandlerImplementation::Shutdown() {
   SendData(kShutdownId, 0, 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)