("_"), colons (":"), and periods (".")'. These regexps

        are slightly over-zealous, in that they remove colons

        and periods unnecessarily.

        Whitespace is transformed into underscores, and then

        anything which is not a hyphen or a character that

        matches \w (alphanumerics and underscore) is removed.

        """

        # Transform all whitespace to underscore

        idstring = re.sub(r'\s', "_", '%s' % idstring)

        # Remove everything that is not a hyphen or a member of \w

        idstring = re.sub(r'(?!-)\W', "", idstring).lower()

        return idstring

    def raw_diff(self):

        """

        Returns raw string as udiff

        """

        udiff_copy = self.copy_iterator()

        if self.__format == 'gitdiff':

            udiff_copy = self._parse_gitdiff(udiff_copy)

        return u''.join(udiff_copy)

    def as_html(self, table_class='code-difftable', line_class='line',

                new_lineno_class='lineno old', old_lineno_class='lineno new',

                code_class='code', enable_comments=False, diff_lines=None):

        """

        Return given diff as html table with customized css classes

        """

        def _link_to_if(condition, label, url):

            """

            Generates a link if condition is meet or just the label if not.

            """

            if condition:

                return '''<a href="%(url)s">%(label)s</a>''' % {

                    'url': url,

                    'label': label

                }

            else:

                return label

        if diff_lines is None:

            diff_lines = self.prepare()

        _html_empty = True

        _html = []

        _html.append('''<table class="%(table_class)s">\n''' % {

            'table_class': table_class

        })

        for diff in diff_lines:

            for line in diff['chunks']:

                _html_empty = False

                for change in line:

                    _html.append('''<tr class="%(lc)s %(action)s">\n''' % {

                        'lc': line_class,

                        'action': change['action']

                    })

                    anchor_old_id = ''

                    anchor_new_id = ''

                    anchor_old = "%(filename)s_o%(oldline_no)s" % {

                        'filename': self._safe_id(diff['filename']),

                        'oldline_no': change['old_lineno']

                    }

                    anchor_new = "%(filename)s_n%(oldline_no)s" % {

                        'filename': self._safe_id(diff['filename']),

                        'oldline_no': change['new_lineno']

                    }

                    cond_old = (change['old_lineno'] != '...' and

                                change['old_lineno'])

                    cond_new = (change['new_lineno'] != '...' and

                                change['new_lineno'])

                    if cond_old:

                        anchor_old_id = 'id="%s"' % anchor_old

                    if cond_new:

                        anchor_new_id = 'id="%s"' % anchor_new

                    ###########################################################

                    # OLD LINE NUMBER

                    ###########################################################

                    _html.append('''\t<td %(a_id)s class="%(olc)s">''' % {

                        'a_id': anchor_old_id,

                        'olc': old_lineno_class

                    })

                    _html.append('''%(link)s''' % {

                        'link': _link_to_if(True, change['old_lineno'],

                                            '#%s' % anchor_old)

                    })

                    _html.append('''</td>\n''')

                    ###########################################################

                    # NEW LINE NUMBER

                    ###########################################################

                    _html.append('''\t<td %(a_id)s class="%(nlc)s">''' % {

                        'a_id': anchor_new_id,

                        'nlc': new_lineno_class

                    })

                    _html.append('''%(link)s''' % {

                        'link': _link_to_if(True, change['new_lineno'],

                                            '#%s' % anchor_new)

                    })

                    _html.append('''</td>\n''')

                    ###########################################################

                    # CODE

                    ###########################################################

                    comments = '' if enable_comments else 'no-comment'

                    _html.append('''\t<td class="%(cc)s %(inc)s">''' % {

                        'cc': code_class,

                        'inc': comments

                    })

                    _html.append('''\n\t\t<pre>%(code)s</pre>\n''' % {

                        'code': change['line']

                    })

                    _html.append('''\t</td>''')

                    _html.append('''\n</tr>\n''')

        _html.append('''</table>''')

        if _html_empty:

            return None

        return ''.join(_html)

    def stat(self):

        """

        Returns tuple of added, and removed lines for this instance

        """

        return self.adds, self.removes

class InMemoryBundleRepo(bundlerepository):

    def __init__(self, ui, path, bundlestream):

        self._tempparent = None

        localrepo.localrepository.__init__(self, ui, path)

        self.ui.setconfig('phases', 'publish', False)

        self.bundle = bundlestream

        # dict with the mapping 'filename' -> position in the bundle

        self.bundlefilespos = {}

def differ(org_repo, org_ref, other_repo, other_ref, discovery_data=None):

    """

    General differ between branches, bookmarks or separate but releated 

    repositories

    :param org_repo:

    :type org_repo:

    :param org_ref:

    :type org_ref:

    :param other_repo:

    :type other_repo:

    :param other_ref:

    :type other_ref:

    """

    bundlerepo = None

    ignore_whitespace = False

    context = 3

    org_repo = org_repo.scm_instance._repo

    other_repo = other_repo.scm_instance._repo

    opts = diffopts(git=True, ignorews=ignore_whitespace, context=context)

    org_ref = org_ref[1]

    other_ref = other_ref[1]

    if org_repo != other_repo:

        common, incoming, rheads = discovery_data

        # create a bundle (uncompressed if other repo is not local)

        if other_repo.capable('getbundle') and incoming:

            # disable repo hooks here since it's just bundle !

            # patch and reset hooks section of UI config to not run any

            # hooks on fetching archives with subrepos

            for k, _ in other_repo.ui.configitems('hooks'):

                other_repo.ui.setconfig('hooks', k, None)

            unbundle = other_repo.getbundle('incoming', common=common,

                                            heads=rheads)

            buf = io.BytesIO()

            while True:

                chunk = unbundle._stream.read(1024 * 4)

                if not chunk:

                    break

                buf.write(chunk)

            buf.seek(0)

            # replace chunked _stream with data that can do tell() and seek()

            unbundle._stream = buf

            ui = make_ui('db')

            bundlerepo = InMemoryBundleRepo(ui, path=org_repo.root,

                                            bundlestream=unbundle)

                                  opts=opts))

    else:

        return ''.join(patch.diff(org_repo, node1=org_ref, node2=other_ref,

                                  opts=opts))