Close stdin in Process.run.

runtime/bin/process_impl.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.
 
 class _ProcessStartStatus {
   int _errorCode;  // Set to OS error code if process start failed.
   String _errorMessage;  // Set to OS error message if process start failed.
 }
 
 
@@ skipping 313 matching lines @@
         if (stderrEncoding is !Encoding) {
           throw new IllegalArgumentException(
               'stderrEncoding option is not an encoding: $stderrEncoding');
         }
       }
     }
 
     // Start the underlying process.
     _process = new _Process.start(path, arguments, options);
 
+    // Make sure stdin is closed.
+    _process.onStart = _process.stdin.close;
+
     // Setup process error handling.
     _process.onError = (e) => _completer.completeException(e);
 
     // Setup process exit handling.
     _process.onExit = (exitCode) {
       _exitCode = exitCode;
       _checkDone();
     };
 
     // Setup stdout handling.
@@ skipping 43 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;
 }