git_cl_hooks: get cl fields vi git_cl accessors instead of using backquote

git_cl_hooks.py

-# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+# Copyright (c) 2010 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.
 
 import os
 import re
 import subprocess
 import sys
 
 import breakpad
 
+from git_cl_repo import git_cl
+from git_cl_repo import upload
+
 import presubmit_support
 import scm
 import watchlists
 
+# Really ugly hack to quiet upload.py
+upload.verbosity = 0
+
 def Backquote(cmd, cwd=None):
   """Like running `cmd` in a shell script."""
   return subprocess.Popen(cmd,
                           cwd=cwd,
                           stdout=subprocess.PIPE).communicate()[0].strip()
 
-def BackquoteAsInteger(cmd, cwd=None):
-  """Like Backquote, but returns either an int or None."""
+def ConvertToInteger(input):
+  """Convert a string to integer, but returns either an int or None."""
   try:
-    return int(Backquote(cmd, cwd))
-  except ValueError:
+    return int(input)
+  except TypeError, ValueError:
     return None
 
 
 class ChangeOptions:
   def __init__(self, commit=None, upstream_branch=None):
     self.commit = commit
     self.verbose = None
     self.default_presubmit = None
     self.may_prompt = None
 
     root = Backquote(['git', 'rev-parse', '--show-cdup'])
     if not root:
       root = "."
     absroot = os.path.abspath(root)
     if not root:
       raise Exception("Could not get root directory.")
     # We use the sha1 of HEAD as a name of this change.
     name = Backquote(['git', 'rev-parse', 'HEAD'])
     files = scm.GIT.CaptureStatus([root], upstream_branch)
-    issue = BackquoteAsInteger(['git', 'cl', 'status', '--field=id'])
-    patchset = BackquoteAsInteger(['git', 'cl', 'status', '--field=patch'])
+    cl = git_cl.Changelist()
+    issue = ConvertToInteger(cl.GetIssue())
+    patchset = ConvertToInteger(cl.GetPatchset())
     if issue:
-      description = Backquote(['git', 'cl', 'status', '--field=desc'])
+      description = cl.GetDescription()
     else:
       # If the change was never uploaded, use the log messages of all commits
       # up to the branch point, as git cl upload will prefill the description
       # with these log messages.
       description = Backquote(['git', 'log', '--pretty=format:%s%n%n%b',
                                '%s...' % (upstream_branch)])
     self.change = presubmit_support.GitChange(name, description, absroot, files,
                                               issue, patchset)
 
 
@@ skipping 15 matching lines @@
   if presubmit_support.DoPresubmitChecks(options.change,
                                          options.commit,
                                          options.verbose,
                                          sys.stdout,
                                          sys.stdin,
                                          options.default_presubmit,
                                          options.may_prompt):
     sys.exit(0)
   else:
     sys.exit(1)