Remember to close the exitHandler when processes have received

runtime/bin/process_patch.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.
 
 patch class Process {
   /* patch */ static Future<Process> start(String executable,
                                            List<String> arguments,
                                            [ProcessOptions options]) {
     _ProcessImpl process = new _ProcessImpl(executable, arguments, options);
     return process._start();
@@ skipping 180 matching lines @@
         void handleExit() {
           _ended = true;
           if (_onExit !== null) {
             _onExit(exitCode(exitDataBuffer));
           }
           _out.close();
         }
 
         exitDataRead += _exitHandler.inputStream.readInto(
             exitDataBuffer, exitDataRead, EXIT_DATA_SIZE - exitDataRead);
-        if (exitDataRead == EXIT_DATA_SIZE) handleExit();
+        if (exitDataRead == EXIT_DATA_SIZE) {
+          _exitHandler.close();
+          handleExit();
+        }
       };
 
       completer.complete(this);
     });
     return completer.future;
   }
 
   bool _startNative(String path,
                     List<String> arguments,
                     String workingDirectory,
@@ skipping 144 matching lines @@
 
 class _ProcessResult implements ProcessResult {
   const _ProcessResult(int this.exitCode,
                        String this.stdout,
                        String this.stderr);
 
   final int exitCode;
   final String stdout;
   final String stderr;
 }