docs: def get_revision(self, location):
          """
          Return the maximum revision for all files under a given location
          """
          # Note: taken from setuptools.command.egg_info
          revision = 0
  
          for base, dirs, files in os.walk(location):
              if self.dirname not in dirs:
                  dirs[:] = []
                  continue    # no sense walking uncontrolled subdirs
              dirs.remove(self.dirname)
              entries_fn = os.path.join(base, self.dirname, 'entries')
              if not os.path.exists(entries_fn):
                  ## FIXME: should we warn?
                  continue
              f = open(entries_fn)
              data = f.read()
              f.close()
  
              if data.startswith('8') or data.startswith('9') or data.startswith('10'):
                  data = list(map(str.splitlines, data.split('\n\x0c\n')))
                  del data[0][0]  # get rid of the '8'
                  dirurl = data[0][3]
                  revs = [int(d[9]) for d in data if len(d)>9 and d[9]]+[0]
                  if revs:
                      localrev = max(revs)
                  else:
                      localrev = 0
              elif data.startswith('<?xml'):
                  dirurl = _svn_xml_url_re.search(data).group(1)    # get repository URL
                  revs = [int(m.group(1)) for m in _svn_rev_re.finditer(data)]+[0]
                  if revs:
                      localrev = max(revs)
                  else:
                      localrev = 0
              else:
                  logger.warn("Unrecognized .svn/entries format; skipping %s", base)
                  dirs[:] = []
                  continue
              if base == location:
                  base_url = dirurl+'/'   # save the root url
              elif not dirurl.startswith(base_url):
                  dirs[:] = []
                  continue    # not part of the same svn tree, skip it
              revision = max(revision, localrev)
          return revision