- Do not keep the environment alive past the process spawn.

runtime/bin/process_patch.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.
 
 patch class _WindowsCodePageDecoder {
   /* patch */ static String _decodeBytes(List<int> bytes)
       native "SystemEncodingToString";
 }
 
 
@@ skipping 142 matching lines @@
 }
 
 
 class _ProcessImpl extends NativeFieldWrapperClass1 implements Process {
   _ProcessImpl(String path,
                List<String> arguments,
                String this._workingDirectory,
                Map<String, String> environment,
                bool includeParentEnvironment,
                bool runInShell) {
-    runInShell = identical(runInShell, true);
     if (runInShell) {
       arguments = _getShellArguments(path, arguments);
       path = _getShellCommand();
     }
 
     if (path is !String) {
       throw new ArgumentError("Path is not a String: $path");
     }
     _path = path;
 
@@ skipping 12 matching lines @@
         _arguments[i] = _windowsArgumentEscape(_arguments[i]);
       }
     }
 
     if (_workingDirectory != null && _workingDirectory is !String) {
       throw new ArgumentError(
           "WorkingDirectory is not a String: $_workingDirectory");
     }
 
     _environment = [];
-    if (environment == null) {
-      environment = {};
-    }
-    if (environment is !Map) {
-      throw new ArgumentError("Environment is not a map: $environment");
-    }
-    if (identical(true, includeParentEnvironment)) {
-      environment = new Map.from(Platform.environment)..addAll(environment);
-    }
-    environment.forEach((key, value) {
+    var environmentEntryHandler = (key, value) {

[Anders Johnsen, 2014/04/10 07:06:44]

void environmentEntryHandler(key, value) {
 ...
}

?

[Ivan Posva, 2014/04/10 07:27:38]

They are equivalent.

[Anders Johnsen, 2014/04/10 08:08:12]

Yes, but very odd style (not what we usually use in dart:io).

       if (key is !String || value is !String) {
         throw new ArgumentError(
-            "Environment key or value is not a string: ($key, $value)");
+        "Environment key or value is not a string: ($key, $value)");

[Anders Johnsen, 2014/04/10 07:06:44]

indentation

       }
       _environment.add('$key=$value');
-    });
+    };
+    if (environment != null) {
+      if (environment is !Map) {
+        throw new ArgumentError("Environment is not a map: $environment");
+      }
+      environment.forEach(environmentEntryHandler);
+    }
+    if (includeParentEnvironment) {
+      Platform.environment.forEach(environmentEntryHandler);

[Anders Johnsen, 2014/04/10 07:06:44]

This is wrong. Now parent environment will override child.

[Ivan Posva, 2014/04/10 07:27:38]

I see it now. It was not obvious in the original code. I'll fix this tomorrow.

[Anders Johnsen, 2014/04/10 08:08:12]

I'll start cooking on a test.

+    }
 
     // stdin going to process.
     _stdin = new _StdSink(new _Socket._writePipe());
     // stdout coming from process.
     _stdout = new _StdStream(new _Socket._readPipe());
     // stderr coming from process.
     _stderr = new _StdStream(new _Socket._readPipe());
     _exitHandler = new _Socket._readPipe();
     _ended = false;
     _started = false;
@@ skipping 92 matching lines @@
       var status = new _ProcessStartStatus();
       bool success = _startNative(_path,
                                   _arguments,
                                   _workingDirectory,
                                   _environment,
                                   _stdin._sink._nativeSocket,
                                   _stdout._stream._nativeSocket,
                                   _stderr._stream._nativeSocket,
                                   _exitHandler._nativeSocket,
                                   status);
+      _environment = null;  // The environment will not be needed going forward.
       if (!success) {
         completer.completeError(
             new ProcessException(_path,
                                  _arguments,
                                  status._errorMessage,
                                  status._errorCode));
         return;
       }
       _started = true;
 
@@ skipping 35 matching lines @@
     var status = new _ProcessStartStatus();
     bool success = _startNative(_path,
                                 _arguments,
                                 _workingDirectory,
                                 _environment,
                                 _stdin._sink._nativeSocket,
                                 _stdout._stream._nativeSocket,
                                 _stderr._stream._nativeSocket,
                                 _exitHandler._nativeSocket,
                                 status);
+    _environment = null;  // The environment will not be needed going forward.
     if (!success) {
       throw new ProcessException(_path,
                                  _arguments,
                                  status._errorMessage,
                                  status._errorCode);
     }
 
     var result = _wait(
         _stdin._sink._nativeSocket,
         _stdout._stream._nativeSocket,
@@ skipping 145 matching lines @@
   const _ProcessResult(int this.pid,
                        int this.exitCode,
                        this.stdout,
                        this.stderr);
 
   final int pid;
   final int exitCode;
   final stdout;
   final stderr;
 }