Work around issue 6984.

utils/pub/io.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.
 
 /**
  * Helper functionality to make working with IO easier.
  */
 library io;
 
 import 'dart:io';
@@ skipping 558 matching lines @@
   }
 
   if (environment != null) {
     options.environment = new Map.from(Platform.environment);
     environment.forEach((key, value) => options.environment[key] = value);
   }
 
   return fn(executable, args, options);
 }
 
+/// Closes [response] while ignoring the body of [request]. Returns a Future
+/// that completes once the response is closed.
+///
+/// Due to issue 6984, it's necessary to drain the request body before closing
+/// the response.
+Future closeHttpResponse(HttpRequest request, HttpResponse response) {
+  var completer = new Completer();
+  request.inputStream.onError = completer.completeException;
+  request.inputStream.onData = request.inputStream.read;
+  request.inputStream.onClosed = () {
+    response.outputStream.close();
+    completer.complete(null);
+  };
+  return completer.future;
+}
+
 /**
  * Wraps [input] to provide a timeout. If [input] completes before
  * [milliseconds] have passed, then the return value completes in the same way.
  * However, if [milliseconds] pass before [input] has completed, it completes
  * with a [TimeoutException] with [description] (which should be a fragment
  * describing the action that timed out).
  *
  * Note that timing out will not cancel the asynchronous operation behind
  * [input].
  */
@@ skipping 304 matching lines @@
   return new Directory(entry);
 }
 
 /**
  * Gets a [Uri] for [uri], which can either already be one, or be a [String].
  */
 Uri _getUri(uri) {
   if (uri is Uri) return uri;
   return new Uri.fromString(uri);
 }