Make sure to never report SocketExceptions on HttpResponse.

sdk/lib/io/http_impl.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;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
   final Completer _dataCompleter = new Completer();
   Stream<List<int>> _stream;
@@ skipping 552 matching lines @@
   _HttpOutboundConsumer(_HttpOutboundMessage this._outbound);
 
   void _cancel() {
     if (_subscription != null) {
       StreamSubscription subscription = _subscription;
       _subscription = null;
       subscription.cancel();
     }
   }
 
+  bool _ignoreError(error)
+    => error is SocketException && _outbound is HttpResponse;
+
   _ensureController() {
     if (_controller != null) return;
     _controller = new StreamController(sync: true,
                                        onPause: () => _subscription.pause(),
                                        onResume: () => _subscription.resume(),
                                        onListen: () => _subscription.resume(),
                                        onCancel: _cancel);
     _outbound._addStream(_controller.stream)
         .then((_) {
                 _cancel();
                 _done();
                 _closeCompleter.complete(_outbound);
               },
               onError: (error) {
                 _socketError = true;
-                if (error is SocketException &&
-                    _outbound is HttpResponse) {
+                if (_ignoreError(error)) {
                   _cancel();
                   _done();
                   _closeCompleter.complete(_outbound);
                 } else {
                   if (!_done(error)) {
                     _closeCompleter.completeError(error);
                   }
                 }
               });
   }
@@ skipping 30 matching lines @@
         cancelOnError: true);
     // Pause the first request.
     if (_controller == null) _subscription.pause();
     _ensureController();
     return _completer.future;
   }
 
   Future close() {
     Future closeOutbound() {
       if (_socketError) return new Future.value(_outbound);
-      return _outbound._close().then((_) => _outbound);
+      return _outbound._close()
+          .catchError((_) {}, test: _ignoreError)
+          .then((_) => _outbound);
     }
     if (_controller == null) return closeOutbound();
     _controller.close();
     return _closeCompleter.future.then((_) => closeOutbound());
   }
 }
 
 
 class _BufferTransformer extends StreamEventTransformer<List<int>, List<int>> {
   static const int MIN_CHUNK_SIZE = 4 * 1024;
@@ skipping 1815 matching lines @@
   final Uri location;
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }