Add test case for issue 7191.

tests/standalone/io/regress_7191_test.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.
+

[ahe, 2012/12/10 13:04:10]

Add a comment to explain the purpose and how this test works.

[Mads Ager (google), 2012/12/10 13:22:48]

Yes, sorry, I did in patch set 2. My comments never got committed. :(

+import 'dart:io';
+import 'dart:isolate';

[ahe, 2012/12/10 13:04:10]

Unnecessary import?

[Mads Ager (google), 2012/12/10 13:22:48]

Yes. Removed in patch set 2 which I did not commit before uploading. :(

+
+main() {
+  var options = new Options();
+  var executable = options.executable;
+  var scriptDir = new Path.fromNative(options.script).directoryPath;
+  var script = scriptDir.append('regress_7191_script.dart').toNativePath();
+  Process.start(executable, [script]).then((process) {
+    process.stdin.write([0]);
+    process.stdout.onData = process.stdout.read;

[ahe, 2012/12/10 13:04:10]

This is not immediately obvious to me.  What does it do?

[Mads Ager (google), 2012/12/10 13:22:48]

It drains stdout and stderr of the sub-process. It might be easier to read if
you have:

process.stdout.onData = () => process.stdout.read();

On each data event, just read the data and ignore it.

+    process.stderr.onData = process.stderr.read;
+    process.stdout.onClosed = () {
+      process.stdin.write([0]);
+    };
+  });
+}