ln_ctx = [ln_ctx]

    if ln_ctx:

        retval = ln_ctx[0].split(':')[-1]

    else:

        retval = ln_ctx_global

    try:

        return int(retval)

    except Exception:

        return 3

def _context_url(GET, fileid=None):

    """

    Generates url for context lines

    :param fileid:

    """

    fileid = str(fileid) if fileid else None

    ig_ws = get_ignore_ws(fileid, GET)

    ln_ctx = (get_line_ctx(fileid, GET) or 3) * 2

    params = defaultdict(list)

    _update_with_GET(params, GET)

    # global option

    if fileid is None:

        if ln_ctx > 0:

            params['context'] += [ln_ctx]

        if ig_ws:

            ig_ws_key = 'ignorews'

            ig_ws_val = 1

    # per file option

    else:

        params[fileid] += ['C:%s' % ln_ctx]

        ig_ws_key = fileid

        ig_ws_val = 'WS:%s' % 1

    if ig_ws:

        params[ig_ws_key] += [ig_ws_val]

    lbl = _('increase diff context to %(num)s lines') % {'num': ln_ctx}

    params['anchor'] = fileid

class ChangesetController(BaseRepoController):

    def __before__(self):

        super(ChangesetController, self).__before__()

        c.affected_files_cut_off = 60

    def __load_data(self):

        repo_model = RepoModel()

        c.users_array = repo_model.get_users_js()

        c.user_groups_array = repo_model.get_user_groups_js()

    def _index(self, revision, method):

        c.anchor_url = anchor_url

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

        c.fulldiff = fulldiff = request.GET.get('fulldiff')

        #get ranges of revisions if preset

        rev_range = revision.split('...')[:2]

        enable_comments = True

        c.cs_repo = c.db_repo

        try:

            if len(rev_range) == 2:

                enable_comments = False

                rev_start = rev_range[0]

                rev_end = rev_range[1]

                rev_ranges = c.db_repo_scm_instance.get_changesets(start=rev_start,

                                                             end=rev_end)

            else:

                rev_ranges = [c.db_repo_scm_instance.get_changeset(revision)]

            c.cs_ranges = list(rev_ranges)

            if not c.cs_ranges:

                raise RepositoryError('Changeset range returned empty result')

        except(ChangesetDoesNotExistError,), e:

            log.error(traceback.format_exc())

            msg = _('Such revision does not exist for this repository')

            h.flash(msg, category='error')

            raise HTTPNotFound()

        c.changes = OrderedDict()

        c.lines_added = 0  # count of lines added

        c.lines_deleted = 0  # count of lines removes

        c.changeset_statuses = ChangesetStatus.STATUSES