Correct the sign of exit codes for the process library.

runtime/bin/process_impl.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.
 
 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 40 matching lines @@
 
     // Make sure to activate socket handlers now that the file
     // descriptors have been set.
     _in._activateHandlers();
     _out._activateHandlers();
     _err._activateHandlers();
 
     // Setup an exit handler to handle internal cleanup and possible
     // callback when a process terminates.
     _exitHandler.dataHandler = () {
-        final int EXIT_DATA_SIZE = 8;
+        final int EXIT_DATA_SIZE = 12;
         List<int> exitDataBuffer = new List<int>(EXIT_DATA_SIZE);
         InputStream input = _exitHandler.inputStream;
         int exitDataRead = 0;
 
         int exitCode(List<int> ints) {
-          return ints[4] + (ints[5] << 8) + (ints[6] << 16) + (ints[7] << 24);
+          var code =
+              ints[4] + (ints[5] << 8) + (ints[6] << 16) + (ints[7] << 24);
+          return (ints[8] == 0) ? code : -code;

[Søren Gjesse, 2011/11/09 15:12:45]

Should we assert that ints[8] is either 0 or 1 and that ints[9], ints[10] and
ints[11] are zero?

Maybe refactor converting 4 bytes to an int into a separate method.

[Mads Ager (google), 2011/11/09 15:37:11]

Thanks! Done. I'm using that method to get the negative indication as well and I
assert that it is either 0 or 1.

         }
 
         int exitPid(List<int> ints) {
           return ints[0] + (ints[1] << 8) + (ints[2] << 16) + (ints[3] << 24);
         }
 
         void handleExit() {
           _processExit(exitPid(exitDataBuffer));
           if (_exitHandlerCallback !== null) {
             _exitHandlerCallback(exitCode(exitDataBuffer));
@@ skipping 83 matching lines @@
   Socket _in;
   Socket _out;
   Socket _err;
   Socket _exitHandler;
   int _pid;
   bool _closed;
   bool _killed;
   bool _started;
   var _exitHandlerCallback;
 }