Fixed maruel@ style nits.

bin/chromite

 #!/usr/bin/python
 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-"""Wapper for the chromite shell.
+"""Wrapper for the chromite shell.
 
 This script is intended to run in several ways:
 - Outside the chroot, it should be _copied_ to someplace that is in the
   path (like depot_tools).  It will search for the right chromite by looking
   for a file 'chromite/shell/main.py' upward based on the CWD.
 - Inside the chroot, it might be _either_ copied to someplace in the path (since
   depot_tools is in the path in the chroot) or it might run from chromite/bin
   directly, which should be in the PATH.  In any case, we'll look for the
   real 'chromite/shell/main.py' based on the environment variable
   CROS_WORKON_SRCROOT, so it doesn't matter what the CWD is.
@@ skipping 23 matching lines @@
 
   # Outside the chroot, search upward until we either end up with a blank dir
   # or the "parent" dir doesn't change.  Either of those is an error case.
   dir = os.getcwd()
   prev_dir = None
   while dir and dir != prev_dir:
     chromite_path = os.path.join(dir, 'chromite', 'shell', 'main.py')
     if os.path.isfile(chromite_path):
       # Add the directory above chromite to PYTHONPATH before executing, so
       # that "import chromite.abc.xyz" works...
-      env = dict(os.environ)
+      env = os.environ.copy()
       if 'PYTHONPATH' in env:
-        env['PYTHONPATH'] = "%s:%s" % (env['PYTHONPATH'], dir)
+        env['PYTHONPATH'] += ':%s' % dir
       else:
         env['PYTHONPATH'] = dir
 
       # Exec the script, which will never return; note that python will
       # replace argv[0] with chromite_path when called, so we'll lose
       # the name of / path to this wrapper.
       os.execve(chromite_path, sys.argv, env)
 
     prev_dir = dir
     dir = os.path.dirname(dir)
 
   # TODO(dianders): Should we actually print out the 'repo init' call that
   # the user should use?
   print (
       "ERROR: Couldn't find the chromite tool.\n"
       "\n"
       "Please change to a directory inside your Chromium OS source tree\n"
       "and retry.  If you need to setup a Chromium OS source tree, see:\n"
       "  http://www.chromium.org/chromium-os/developer-guide"
   )