Add Popen.shell, add more subprocess2 tests and make it more compact.

subprocess2.py

 # coding=utf8
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """Collection of subprocess wrapper functions.
 
 In theory you shouldn't need anything else in subprocess, or this module failed.
 """
 
 from __future__ import with_statement
 import errno
 import logging
 import os
 import subprocess
 import sys
 import tempfile
 import time
 import threading
 
+
 # Constants forwarded from subprocess.
 PIPE = subprocess.PIPE
 STDOUT = subprocess.STDOUT
 # Sends stdout or stderr to os.devnull.
 VOID = object()
 # Error code when a process was killed because it timed out.
 TIMED_OUT = -2001
 
 # Globals.
 # Set to True if you somehow need to disable this hack.
@@ skipping 145 matching lines @@
         # Create a temporary file to workaround python's deadlock.
         # http://docs.python.org/library/subprocess.html#subprocess.Popen.wait
         # When the pipe fills up, it will deadlock this process. Using a real
         # file works around that issue.
         kwargs[stream] = open(os.devnull, 'w')
 
     fix('stdout')
     fix('stderr')
 
     self.start = time.time()
+    self.shell = kwargs.get('shell', None)
     # Silence pylint on MacOSX
     self.returncode = None
+
     try:
       super(Popen, self).__init__(args, **kwargs)
     except OSError, e:
       if e.errno == errno.EAGAIN and sys.platform == 'cygwin':
         # Convert fork() emulation failure into a CygwinRebaseError().
         raise CygwinRebaseError(
             e.errno,
             args,
             kwargs.get('cwd'),
             None,
@@ skipping 34 matching lines @@
     else:
       return proc.communicate(), proc.returncode
 
   # Create a temporary file to workaround python's deadlock.
   # http://docs.python.org/library/subprocess.html#subprocess.Popen.wait
   # When the pipe fills up, it will deadlock this process. Using a real file
   # works around that issue.
   with tempfile.TemporaryFile() as buff:
     kwargs['stdout'] = buff
     proc = Popen(args, **kwargs)
+    if proc.shell:
+      raise TypeError(
+          'Using timeout and shell simultaneously will cause a process leak '
+          'since the shell will be killed instead of the child process.')
     if stdin is not None:
       proc.stdin.write(stdin)
     while proc.returncode is None:
       proc.poll()
       if timeout and (time.time() - proc.start) > timeout:
         proc.kill()
         proc.wait()
         # It's -9 on linux and 1 on Windows. Standardize to TIMED_OUT.
         proc.returncode = TIMED_OUT
       time.sleep(0.001)
@@ skipping 56 matching lines @@
 
   - Throws if return code is not 0.
   - Works even prior to python 2.7.
   - Blocks stdin by default if not specified since no output will be visible.
   - As per doc, "The stdout argument is not allowed as it is used internally."
   """
   kwargs.setdefault('stdin', VOID)
   if 'stdout' in kwargs:
     raise ValueError('stdout argument not allowed, it will be overridden.')
   return check_call_out(args, stdout=PIPE, **kwargs)[0]