Fix few errors in env_dump.py.

build/env_dump.py

 #!/usr/bin/python
 # Copyright 2013 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.
 
 # This script can either source a file and dump the enironment changes done by
 # it, or just simply dump the current environment as JSON into a file.
 
 import json
 import optparse
 import os
+import pipes
 import subprocess
 import sys
 
 
 def main():
   parser = optparse.OptionParser()
   parser.add_option('-f', '--output-json',
                     help='File to dump the environment as JSON into.')
   parser.add_option(
       '-d', '--dump-mode', action='store_true',
       help='Dump the environment to the file and exit immediately.')
 
   options, args = parser.parse_args()
   if not options.output_json:
     parser.error('Requires --output-json option.')
 
   if options.dump_mode:
     if args:
       parser.error("Cannot specify args with --dump-mode")
     with open(options.output_json, 'w') as f:
       json.dump(dict(os.environ), f)
   else:
-    envsetup_cmd = ' '.join(args)
+    envsetup_cmd = ' '.join(map(pipes.quote, args))
     full_cmd = [
         'bash', '-c',
-        '. %s; ./%s -d -f %s' % (envsetup_cmd, __file__, options.output_json)]
+        '. %s; %s -d -f %s' % (envsetup_cmd, os.path.abspath(__file__),
+                               options.output_json)
+    ]
     ret = subprocess.call(full_cmd)
     if ret:
-      sys.exit('Error running %s and dumping env', envsetup_cmd)
+      sys.exit('Error running %s and dumping env' % envsetup_cmd)
 
 
 if __name__ == '__main__':
   sys.exit(main())