Run pychecker over most scripts in depot_tools. Catched a few bugs.

presubmit_support.py

 #!/usr/bin/python
 # Copyright (c) 2006-2009 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.
 
 """Enables directory-specific presubmit checks to run at upload and/or commit.
 """
 
 __version__ = '1.3.3'
 
@@ skipping 327 matching lines @@
       a 3 tuple:
         the AffectedFile instance of the current file;
         integer line number (1-based); and
         the contents of the line as a string.
 
     Note: The cariage return (LF or CR) is stripped off.
     """
     files = self.AffectedSourceFiles(source_file_filter)
     return InputApi._RightHandSideLinesImpl(files)
 
-  def ReadFile(self, file, mode='r'):
+  def ReadFile(self, file_item, mode='r'):
     """Reads an arbitrary file.
 
     Deny reading anything outside the repository.
     """
-    if isinstance(file, AffectedFile):
-      file = file.AbsoluteLocalPath()
-    if not file.startswith(self.change.RepositoryRoot()):
+    if isinstance(file_item, AffectedFile):
+      file_item = file_item.AbsoluteLocalPath()
+    if not file_item.startswith(self.change.RepositoryRoot()):
       raise IOError('Access outside the repository root is denied.')
-    return gcl.ReadFile(file, mode)
+    return gcl.ReadFile(file_item, mode)
 
   @staticmethod
   def _RightHandSideLinesImpl(affected_files):
     """Implements RightHandSideLines for InputApi and GclChange."""
     for af in affected_files:
       lines = af.NewContents()
       line_number = 0
       for line in lines:
         line_number += 1
         yield (af, line_number, line)
@@ skipping 614 matching lines @@
         dirs.remove('.git')
       for name in files:
         if fnmatch.fnmatch(name, mask):
           results.append(os.path.join(root, name))
     return results
 
 
 def ParseFiles(args, recursive):
   files = []
   for arg in args:
-    files.extend([('M', file) for file in ScanSubDirs(arg, recursive)])
+    files.extend([('M', f) for f in ScanSubDirs(arg, recursive)])
   return files
 
 
 def Main(argv):
   parser = optparse.OptionParser(usage="%prog [options]",
                                  version="%prog " + str(__version__))
   parser.add_option("-c", "--commit", action="store_true", default=False,
                    help="Use commit instead of upload checks")
   parser.add_option("-u", "--upload", action="store_false", dest='commit',
                    help="Use upload instead of commit checks")
@@ skipping 45 matching lines @@
                                options.commit,
                                options.verbose,
                                sys.stdout,
                                sys.stdin,
                                options.default_presubmit,
                                options.may_prompt)
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))