Include parent environment by default, add option to not, for Process.

sdk/lib/io/process.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.
 
 part of dart.io;
 
 // TODO(ager): The only reason for this class is that we
 // cannot patch a top-level at this point.
 class _ProcessUtils {
   external static void _exit(int status);
@@ skipping 65 matching lines @@
    * that the change of directory occurs before executing the process on some
    * platforms, which may have impact when using relative paths for the
    * executable and the arguments.
    *
    * Use [environment] to set the environment variables for the process. If not
    * set the environment of the parent process is inherited. Currently, only
    * US-ASCII environment variables are supported and errors are likely to occur
    * if an environment variable with code-points outside the US-ASCII range is
    * passed in.
    *
+   * If [includeParentEnvironment] is `true`, the process's environment will
+   * include the parent process's environment, with [environment] taking
+   * precedence. Default is `true`.
+   *
    * If [runInShell] is true, the process will be spawned through a system
    * shell. On Linux and Mac OS, [:/bin/sh:] is used, while
    * [:%WINDIR%\system32\cmd.exe:] is used on Windows.
    *
    * Users must read all data coming on the [stdout] and [stderr]
    * streams of processes started with [:Process.start:]. If the user
    * does not read all data on the streams the underlying system
    * resources will not be freed since there is still pending data.
    */
   external static Future<Process> start(
       String executable,
       List<String> arguments,
       {String workingDirectory,
        Map<String, String> environment,
+       bool includeParentEnvironment: true,
        bool runInShell: false});
 
   /**
    * Starts a process and runs it non-interactively to completion. The
    * process run is [executable] with the specified [arguments].
    *
    * Use [workingDirectory] to set the working directory for the process. Note
    * that the change of directory occurs before executing the process on some
    * platforms, which may have impact when using relative paths for the
    * executable and the arguments.
    *
    * Use [environment] to set the environment variables for the process. If not
    * set the environment of the parent process is inherited. Currently, only
    * US-ASCII environment variables are supported and errors are likely to occur
    * if an environment variable with code-points outside the US-ASCII range is
    * passed in.
    *
+   * If [includeParentEnvironment] is `true`, the process's environment will
+   * include the parent process's environment, with [environment] taking
+   * precedence. Default is `true`.
+   *
    * If [runInShell] is true, the process will be spawned through a system
    * shell. On Linux and Mac OS, `/bin/sh` is used, while
    * `%WINDIR%\system32\cmd.exe` is used on Windows.
    *
    * The encoding used for decoding `stdout` and `stderr` into text is
    * controlled through [stdoutEncoding] and [stderrEncoding]. The
    * default encoding is `Encoding.SYSTEM`. If `null` is used no
    * decoding will happen and the [ProcessResult] will hold binary
    * data.
    *
    * Returns a `Future<ProcessResult>` that completes with the
    * result of running the process, i.e., exit code, standard out and
    * standard in.
    */
   external static Future<ProcessResult> run(
       String executable,
       List<String> arguments,
       {String workingDirectory,
        Map<String, String> environment,
+       bool includeParentEnvironment: true,
        bool runInShell: false,
        Encoding stdoutEncoding: Encoding.SYSTEM,
        Encoding stderrEncoding: Encoding.SYSTEM});
 
   /**
    * Returns the standard output stream of the process as a [:Stream:].
    *
    * Throws an [UnsupportedError] if the process is
    * non-interactive.
    */
@@ skipping 142 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;
 }