if submodules:

        return ''

    for filenode in (filenode_old, filenode_new):

        if not isinstance(filenode, FileNode):

            raise VCSError("Given object should be FileNode object, not %s"

                % filenode.__class__)

    repo = filenode_new.changeset.repository

    old_raw_id = getattr(filenode_old.changeset, 'raw_id', repo.EMPTY_CHANGESET)

    new_raw_id = getattr(filenode_new.changeset, 'raw_id', repo.EMPTY_CHANGESET)

    vcs_gitdiff = repo.get_diff(old_raw_id, new_raw_id, filenode_new.path,

                                 ignore_whitespace, context)

    return vcs_gitdiff

class DiffProcessor(object):

    """

    Give it a unified diff and it returns a list of the files that were

    mentioned in the diff together with a dict of meta information that

    can be used to render it in a HTML template.

    """

    _chunk_re = re.compile(r'@@ -(\d+)(?:,(\d+))? \+(\d+)(?:,(\d+))? @@(.*)')

    def __init__(self, diff, differ='diff', format='gitdiff'):

        """

        :param diff:   a text in diff format or generator

        :param format: format of diff passed, `udiff` or `gitdiff`

        """

        if isinstance(diff, basestring):

            diff = [diff]

        self.__udiff = diff

        self.__format = format

        self.adds = 0

        self.removes = 0

        if isinstance(self.__udiff, basestring):

            self.lines = iter(self.__udiff.splitlines(1))

        elif self.__format == 'gitdiff':

            udiff_copy = self.copy_iterator()

            self.lines = imap(self.escaper, self._parse_gitdiff(udiff_copy))

        else:

            udiff_copy = self.copy_iterator()

            self.lines = imap(self.escaper, udiff_copy)

                    lines = []

                    chunks.append(lines)

                    old_line, old_end, new_line, new_end = \

                        [int(x or 1) for x in match.groups()[:-1]]

                    old_line -= 1

                    new_line -= 1

                    gr = match.groups()

                    context = len(gr) == 5

                    old_end += old_line

                    new_end += new_line

                    if context:

                        # skip context only if it's first line

                        if int(gr[0]) > 1:

                            lines.append({

                                'old_lineno': '...',

                                'new_lineno': '...',

                                'action':     'context',

                                'line':       line,

                            })

                    line = lineiter.next()

                    while old_line < old_end or new_line < new_end:

                        if line:

                        else:

                            command = ' '

                        affects_old = affects_new = False

                        # ignore those if we don't expect them

                        if command in '#@':

                            continue

                        elif command == '+':

                            affects_new = True

                            action = 'add'

                            stats[0] += 1

                        elif command == '-':

                            affects_old = True

                            action = 'del'

                            stats[1] += 1

                        else:

                            affects_old = affects_new = True

                            action = 'unmod'

                            old_line += affects_old

                            new_line += affects_new

                            lines.append({

                                'old_lineno':   affects_old and old_line or '',

                                'new_lineno':   affects_new and new_line or '',

                                'action':       action,

                                'line':         line

                            })

                        line = lineiter.next()

        except StopIteration:

            pass

        sorter = lambda info: {'A': 0, 'M': 1, 'D': 2}.get(info['operation'])

        if inline_diff is False:

            return sorted(files, key=sorter)

        # highlight inline changes

        for diff_data in files:

            for chunk in diff_data['chunks']:

                lineiter = iter(chunk)

                try:

                    while 1:

                        line = lineiter.next()

                        if line['action'] not in ['unmod', 'context']:

                            nextline = lineiter.next()

                            if nextline['action'] in ['unmod', 'context'] or \

                               nextline['action'] == line['action']:

                                continue

                            self.differ(line, nextline)

                except StopIteration:

                    pass