Add optional workingDirectory argument to Process.start.

runtime/bin/process.dart

 // Copyright (c) 2011, 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.
 
 interface Process default _Process {
   /**
    * Creates a new process object and starts a process running the executable
    * found at [path] with the specified [arguments]. When the process has
    * been successfully started the [startHandler] is called. If the process
-   * fails to start the [errorHandler] is called.
+   * fails to start the [errorHandler] is called. An optional 
+   * [workingDirectory] can be passed to specify where the process is run 
+   * from.

[Søren Gjesse, 2012/01/05 09:30:47]

I think there should be some additional info on the use of relative paths here.
On Linux and Mac OS the change of working directory happens before locating the
executable whereas from the Windows documentation of CreateProcess it seems that
that might not be the case. Maybe just a comment on that combining relative
paths for the executable with a working directory might work differently on
different platforms.

[Anders Johnsen, 2012/01/05 09:50:49]

Nice observation, added further comments.

    *
    * No data can be written to the process stdin and the process cannot be
    * closed nor killed before the [startHandler] has been invoked.
    */
-  Process.start(String path, List<String> arguments);
+  Process.start(String path, List<String> arguments, [String workingDirectory]);

[Søren Gjesse, 2012/01/05 09:30:47]

Maybe we should rename path to executable.

[Anders Johnsen, 2012/01/05 09:50:49]

Agreed.

 
   /**
    * Returns an input stream of the process stdout.
    */
   InputStream get stdout();
 
   /**
    * Returns an input stream of the process stderr.
    */
   InputStream get stderr();
@@ skipping 45 matching lines @@
   /**
    * Contains the system message for the process exception if any.
    */
   final String message;
 
   /**
    * Contains the OS error code for the process exception if any.
    */
   final int errorCode;
 }