Fix stdin_sync_test on Windows.

tests/standalone/io/stdin_sync_test.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.
 
 import "dart:io";
 import "dart:json";
 
 void test(String line, List<String> expected) {
   var script = new Path(Platform.script).directoryPath;
   script = script.append("stdin_sync_script.dart");
@@ skipping 19 matching lines @@
   });
 }
 
 void main() {
   test("hej\x01\x00\x0d\x0a\x0a4\x0a", ['hej\x01\x00', '', '4']);
 
   test("hej\u0187", ['hej\u0187']);
 
   test("hej\rhej\nhej\r", ['hej\rhej', 'hej\r']);
 
-  test("hej\r\r\nhej\r\nhej\r", ['hej\r', 'hej', 'hej\r']);
+  if (Platform.isWindows) {
+    // Windows trim one of the \r.
+    test("hej\r\r\r\nhej\r\nhej\r", ['hej\r', 'hej', 'hej\r']);
+  } else {
+    test("hej\r\r\nhej\r\nhej\r", ['hej\r', 'hej', 'hej\r']);

[Bill Hesse, 2013/07/02 14:49:43]

This indicates an error in the newline handling with subprocesses.

I'm pretty sure that the standard for Windows is that all file handles and
descriptors for stdin, stdout, and stderr are in text mode, which means that
"\r\n" on the file/pipe/stream are converted to "\n" before being exposed to C
code, by stdlib.  So our Dart code, and our C++ implementation of Dart IO, is
only seeing \n.

I think we need to maintain this, so that interoperability with other languages
works with Process.
If Dart has a Python or C subprocess, then \n and \r\n sent from Dart should be
received as \n and \r\n by Python or C.  If Python or C start a Dart subprocess,
then \n and \r\n should also be communicated correctly.  Similarly when Dart has
its stdin and stdout redirected to a file.

It may be that the only problem is the Handle/file descriptors created in Dart
when Process.start is called may not be in text mode.  That would explain the
problem here.

We should create a bug, and a series of tests.

+  }
 
   test("hej", ['hej']);
 }