revinfo: Properly use git HEAD or svn BASE revisions

scm.py

 # 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.
 
 """SCM-specific utility classes."""
 
 import glob
 import os
 import re
 import shutil
@@ skipping 476 matching lines @@
     """Get the head revision of a SVN repository.
 
     Returns:
       Int head revision
     """
     info = SVN.Capture(["info", "--xml", url], os.getcwd())
     dom = xml.dom.minidom.parseString(info)
     return dom.getElementsByTagName('entry')[0].getAttribute('revision')
 
   @staticmethod
+  def CaptureBaseRevision(cwd):
+    """Get the base revision of a SVN repository.
+
+    Returns:
+      Int base revision
+    """
+    info = SVN.Capture(["info", "--xml"], cwd)
+    dom = xml.dom.minidom.parseString(info)
+    return dom.getElementsByTagName('entry')[0].getAttribute('revision')
+
+  @staticmethod
   def CaptureStatus(files):
     """Returns the svn 1.5 svn status emulated output.
 
     @files can be a string (one file) or a list of files.
 
     Returns an array of (status, file) tuples."""
     command = ["status", "--xml"]
     if not files:
       pass
     elif isinstance(files, basestring):
@@ skipping 238 matching lines @@
     if not cur_dir_repo_root:
       return None
 
     while True:
       parent = os.path.dirname(directory)
       if (SVN.CaptureInfo(parent, print_error=False).get(
               "Repository Root") != cur_dir_repo_root):
         break
       directory = parent
     return GetCasedPath(directory)