Rewrite the Future-pipeline from the Socket to the HttpClientRequest/HttpResponse.

sdk/lib/io/io_stream_consumer.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;
 
 /**
  * Helper class to wrap a [StreamConsumer<List<int>, T>] and provide utility
  * functions for writing to the StreamConsumer directly. The [IOSink]
  * buffers the input given by [add] and [addString] and will delay a [consume]
@@ skipping 126 matching lines @@
     _controller;
     Completer<T> unbindCompleter;
     if (unbind) {
       unbindCompleter = new Completer<T>();
     }
     _bindSubscription = stream.listen(
         _controller.add,
         onDone: () {
           _bindSubscription = null;
           if (unbind) {
-            unbindCompleter.complete(null);
+            if (unbindCompleter != null) {
+              unbindCompleter.complete(null);
+              unbindCompleter = null;
+            }
           } else {
             _controller.close();
           }
         },
         onError: _controller.signalError);
     if (_paused) _pause();
     if (unbind) {
+      _pipeFuture.catchError((error) {
+        if (unbindCompleter != null) {
+          unbindCompleter.completeError(error);
+        }
+      });
       return unbindCompleter.future;
     } else {
       return _pipeFuture;
     }
   }
 }