Dart: Fixes bug in MojoEventStreamListener

mojo/public/dart/src/event_stream.dart

 // Copyright 2014 The Chromium Authors. 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 core;
 
 class MojoEventStream extends Stream<List<int>> {
   // The underlying Mojo handle.
   MojoHandle _handle;
 
@@ skipping 161 matching lines @@
     _eventStream = new MojoEventStream(handle);
     _isOpen = false;
   }
 
   StreamSubscription<List<int>> listen({Function onClosed}) {
     assert(isBound && (subscription == null));
     _isOpen = true;
     subscription = _eventStream.listen((List<int> event) {
       var signalsWatched = new MojoHandleSignals(event[0]);
       var signalsReceived = new MojoHandleSignals(event[1]);
-      if (signalsReceived.isPeerClosed) {
-        if (onClosed != null) onClosed();
-        close();
-        // The peer being closed obviates any other signal we might
-        // have received since we won't be able to read or write the handle.
-        // Thus, we just return before invoking other handlers.
-        return;
-      }
       _isInHandler = true;
       if (signalsReceived.isReadable) {
         assert(_eventStream.readyRead);
         handleRead();
       }
       if (signalsReceived.isWritable) {
         assert(_eventStream.readyWrite);
         handleWrite();
       }
       if (_isOpen) {
         _eventStream.enableSignals(signalsWatched);
       }
       _isInHandler = false;
+      if (signalsReceived.isPeerClosed) {
+        if (onClosed != null) onClosed();
+        close();
+        // The peer being closed obviates any other signal we might
+        // have received since we won't be able to read or write the handle.
+        // Thus, we just return before invoking other handlers.
+        return;
+      }
     }, onDone: close);
     return subscription;
   }
 
   void close() {
     _isOpen = false;
     _endpoint = null;
     subscription = null;
     if (_eventStream != null) {
       _eventStream.close();
       _eventStream = null;
     }
   }
 
   void handleRead() {}
   void handleWrite() {}
 
   MojoMessagePipeEndpoint get endpoint => _endpoint;
   bool get isOpen => _isOpen;
   bool get isInHandler => _isInHandler;
   bool get isBound => _endpoint != null;
 }