fileid = str(fileid) if fileid else None

    params = defaultdict(list)

    _update_with_GET(params, GET)

    lbl = _('Show whitespace')

    ig_ws = get_ignore_ws(fileid, GET)

    ln_ctx = get_line_ctx(fileid, GET)

    # global option

    if fileid is None:

        if ig_ws is None:

            params['ignorews'] += [1]

            lbl = _('Ignore whitespace')

        ctx_key = 'context'

        ctx_val = ln_ctx

    # per file options

    else:

        if ig_ws is None:

            params[fileid] += ['WS:1']

            lbl = _('Ignore whitespace')

        ctx_key = fileid

        ctx_val = 'C:%s' % ln_ctx

    # if we have passed in ln_ctx pass it along to our params

    if ln_ctx:

        params[ctx_key] += [ctx_val]

    params['anchor'] = fileid

    icon = h.literal('<i class="icon-strike"></i>')

    return h.link_to(icon, h.url.current(**params), title=lbl, **{'data-toggle': 'tooltip'})

def get_line_ctx(fid, GET):

    ln_ctx_global = GET.get('context')

    if fid:

        ln_ctx = filter(lambda k: k.startswith('C'), GET.getall(fid))

    else:

        _ln_ctx = filter(lambda k: k.startswith('C'), GET)

        ln_ctx = GET.get(_ln_ctx[0]) if _ln_ctx else ln_ctx_global

        if ln_ctx:

            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

    icon = h.literal('<i class="icon-sort"></i>')

    return h.link_to(icon, h.url.current(**params), title=lbl, **{'data-toggle': 'tooltip'})

# Could perhaps be nice to have in the model but is too high level ...

def create_comment(text, status, f_path, line_no, revision=None, pull_request_id=None, closing_pr=None):

    """Comment functionality shared between changesets and pullrequests"""

    f_path = f_path or None

    line_no = line_no or None

    comment = ChangesetCommentsModel().create(

        text=text,

        repo=c.db_repo.repo_id,

        author=request.authuser.user_id,

        revision=revision,

        pull_request=pull_request_id,

        f_path=f_path,

        line_no=line_no,

        status_change=ChangesetStatus.get_status_lbl(status) if status else None,

        closing_pr=closing_pr,

    )

    return comment

class ChangesetController(BaseRepoController):

    def _before(self, *args, **kwargs):

        super(ChangesetController, self)._before(*args, **kwargs)

        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.pull_request = None

        c.anchor_url = anchor_url

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

        c.fulldiff = request.GET.get('fulldiff') # for reporting number of changed files

        # 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, EmptyRepositoryError):

            log.debug(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

        comments = dict()

        c.statuses = []

        c.inline_comments = []

        c.inline_cnt = 0

        # Iterate over ranges (default changeset view is always one changeset)

        for changeset in c.cs_ranges:

            if method == 'show':

                c.statuses.extend([ChangesetStatusModel().get_status(

                            c.db_repo.repo_id, changeset.raw_id)])

                # Changeset comments

                comments.update((com.comment_id, com)

                                for com in ChangesetCommentsModel()

                                .get_comments(c.db_repo.repo_id,

                                              revision=changeset.raw_id))

                # Status change comments - mostly from pull requests

                comments.update((st.comment_id, st.comment)

                                for st in ChangesetStatusModel()

                                .get_statuses(c.db_repo.repo_id,

                                              changeset.raw_id, with_revisions=True)

                                if st.comment_id is not None)

                inlines = ChangesetCommentsModel() \

                            .get_inline_comments(c.db_repo.repo_id,

                                                 revision=changeset.raw_id)

                c.inline_comments.extend(inlines)

            cs2 = changeset.raw_id

            cs1 = changeset.parents[0].raw_id if changeset.parents else EmptyChangeset().raw_id

            context_lcl = get_line_ctx('', request.GET)

            ign_whitespace_lcl = get_ignore_ws('', request.GET)

                ignore_whitespace=ign_whitespace_lcl, context=context_lcl)

            diff_limit = None if c.fulldiff else self.cut_off_limit

            file_diff_data = []

            if method == 'show':

                diff_processor = diffs.DiffProcessor(raw_diff,

                                                     vcs=c.db_repo_scm_instance.alias,

                                                     diff_limit=diff_limit)

                c.limited_diff = diff_processor.limited_diff

                for f in diff_processor.parsed:

                    st = f['stats']

                    c.lines_added += st['added']

                    c.lines_deleted += st['deleted']

                    filename = f['filename']

                    fid = h.FID(changeset.raw_id, filename)

                    url_fid = h.FID('', filename)

                    html_diff = diffs.as_html(enable_comments=enable_comments, parsed_lines=[f])

                    file_diff_data.append((fid, url_fid, f['operation'], f['old_filename'], filename, html_diff, st))

            else:

                # downloads/raw we only need RAW diff nothing else

                file_diff_data.append(('', None, None, None, raw_diff, None))

            c.changes[changeset.raw_id] = (cs1, cs2, file_diff_data)

        # sort comments in creation order

        c.comments = [com for com_id, com in sorted(comments.items())]

        # count inline comments

        for __, lines in c.inline_comments:

            for comments in lines.values():

                c.inline_cnt += len(comments)

        if len(c.cs_ranges) == 1:

            c.changeset = c.cs_ranges[0]

            c.parent_tmpl = ''.join(['# Parent  %s\n' % x.raw_id

                                     for x in c.changeset.parents])

        if method == 'download':

            response.content_type = 'text/plain'

            response.content_disposition = 'attachment; filename=%s.diff' \

                                            % revision[:12]

            return raw_diff

        elif method == 'patch':

            response.content_type = 'text/plain'

            c.diff = safe_unicode(raw_diff)

            return render('changeset/patch_changeset.html')

        elif method == 'raw':

            response.content_type = 'text/plain'

            return raw_diff

        elif method == 'show':

            self.__load_data()

            if len(c.cs_ranges) == 1:

                return render('changeset/changeset.html')

            else:

                c.cs_ranges_org = None

                c.cs_comments = {}

                revs = [ctx.revision for ctx in reversed(c.cs_ranges)]

                c.jsdata = graph_data(c.db_repo_scm_instance, revs)

                return render('changeset/changeset_range.html')

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def index(self, revision, method='show'):

        return self._index(revision, method=method)

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def changeset_raw(self, revision):

        return self._index(revision, method='raw')

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def changeset_patch(self, revision):

        return self._index(revision, method='patch')

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def changeset_download(self, revision):

        return self._index(revision, method='download')

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def comment(self, repo_name, revision):

        assert request.environ.get('HTTP_X_PARTIAL_XHR')

        status = request.POST.get('changeset_status')

        text = request.POST.get('text', '').strip()

        c.comment = create_comment(

            text,

            status,

            revision=revision,

            f_path=request.POST.get('f_path'),

            line_no=request.POST.get('line'),

        )

        # get status if set !

        if status:

            # if latest status was from pull request and it's closed

            # disallow changing status ! RLY?

            try:

                ChangesetStatusModel().set_status(

                    c.db_repo.repo_id,

                    status,

                    request.authuser.user_id,

                    c.comment,

                    revision=revision,

                    dont_allow_on_closed_pull_request=True,

                )

            except StatusChangeOnClosedPullRequestError:

                log.debug('cannot change status on %s with closed pull request', revision)

                raise HTTPBadRequest()

        action_logger(request.authuser,

                      'user_commented_revision:%s' % revision,

                      c.db_repo, request.ip_addr)

        Session().commit()

        data = {

           'target_id': h.safeid(h.safe_unicode(request.POST.get('f_path'))),

        }

        if c.comment is not None:

            data.update(c.comment.get_dict())

            data.update({'rendered_text':

                         render('changeset/changeset_comment_block.html')})

        return data

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def delete_comment(self, repo_name, comment_id):

        co = ChangesetComment.get_or_404(comment_id)

        if co.repo.repo_name != repo_name:

            raise HTTPNotFound()

        owner = co.author_id == request.authuser.user_id

        repo_admin = h.HasRepoPermissionLevel('admin')(repo_name)

        if h.HasPermissionAny('hg.admin')() or repo_admin or owner:

            ChangesetCommentsModel().delete(comment=co)

            Session().commit()

            return True

        else:

            raise HTTPForbidden()

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def changeset_info(self, repo_name, revision):

        if request.is_xhr:

            try:

                return c.db_repo_scm_instance.get_changeset(revision)

            except ChangesetDoesNotExistError as e:

                return EmptyChangeset(message=str(e))

        else:

            raise HTTPBadRequest()

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def changeset_children(self, repo_name, revision):

        if request.is_xhr:

            changeset = c.db_repo_scm_instance.get_changeset(revision)

            result = {"results": []}

            if changeset.children:

                result = {"results": changeset.children}

            return result

        else:

            raise HTTPBadRequest()

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def changeset_parents(self, repo_name, revision):

        if request.is_xhr:

            changeset = c.db_repo_scm_instance.get_changeset(revision)

            result = {"results": []}

            if changeset.parents:

                result = {"results": changeset.parents}

            return result

        else:

            raise HTTPBadRequest()

    def _get_changesets(alias, org_repo, org_rev, other_repo, other_rev):

        """

        Returns lists of changesets that can be merged from org_repo@org_rev

        to other_repo@other_rev

        ... and the other way

        ... and the ancestors that would be used for merge

        :param org_repo: repo object, that is most likely the original repo we forked from

        :param org_rev: the revision we want our compare to be made

        :param other_repo: repo object, most likely the fork of org_repo. It has

            all changesets that we need to obtain

        :param other_rev: revision we want out compare to be made on other_repo

        """

        ancestors = None

        if org_rev == other_rev:

            org_changesets = []

            other_changesets = []

        elif alias == 'hg':

            # case two independent repos

            if org_repo != other_repo:

                hgrepo = unionrepo.unionrepository(other_repo.baseui,

                                                   other_repo.path,

                                                   org_repo.path)

                # all ancestors of other_rev will be in other_repo and

                # rev numbers from hgrepo can be used in other_repo - org_rev ancestors cannot

            # no remote compare do it on the same repository

            else:

                hgrepo = other_repo._repo

            ancestors = [hgrepo[ancestor].hex() for ancestor in

                         hgrepo.revs("id(%s) & ::id(%s)", other_rev, org_rev)]

            if ancestors:

                log.debug("shortcut found: %s is already an ancestor of %s", other_rev, org_rev)

            else:

                log.debug("no shortcut found: %s is not an ancestor of %s", other_rev, org_rev)

                ancestors = [hgrepo[ancestor].hex() for ancestor in

                             hgrepo.revs("heads(::id(%s) & ::id(%s))", org_rev, other_rev)] # FIXME: expensive!

            other_revs = hgrepo.revs("ancestors(id(%s)) and not ancestors(id(%s)) and not id(%s)",

                                     other_rev, org_rev, org_rev)

            other_changesets = [other_repo.get_changeset(rev) for rev in other_revs]

            org_revs = hgrepo.revs("ancestors(id(%s)) and not ancestors(id(%s)) and not id(%s)",

                                   org_rev, other_rev, other_rev)

            org_changesets = [org_repo.get_changeset(hgrepo[rev].hex()) for rev in org_revs]

        elif alias == 'git':

            if org_repo != other_repo:

                from dulwich.repo import Repo

                from dulwich.client import SubprocessGitClient

                gitrepo = Repo(org_repo.path)

                SubprocessGitClient(thin_packs=False).fetch(safe_str(other_repo.path), gitrepo)

                gitrepo_remote = Repo(other_repo.path)

                SubprocessGitClient(thin_packs=False).fetch(safe_str(org_repo.path), gitrepo_remote)

                revs = [

                    x.commit.id

                    for x in gitrepo_remote.get_walker(include=[other_rev],

                                                       exclude=[org_rev])

                ]

                other_changesets = [other_repo.get_changeset(rev) for rev in reversed(revs)]

                if other_changesets:

                    ancestors = [other_changesets[0].parents[0].raw_id]

                else:

                    # no changesets from other repo, ancestor is the other_rev

                    ancestors = [other_rev]

                gitrepo.close()

                gitrepo_remote.close()

            else:

                so, se = org_repo.run_git_command(

                    ['log', '--reverse', '--pretty=format:%H',

                     '-s', '%s..%s' % (org_rev, other_rev)]

                )

                other_changesets = [org_repo.get_changeset(cs)

                              for cs in re.findall(r'[0-9a-fA-F]{40}', so)]

                so, se = org_repo.run_git_command(

                    ['merge-base', org_rev, other_rev]

                )

                ancestors = [re.findall(r'[0-9a-fA-F]{40}', so)[0]]

            org_changesets = []

        else:

            raise Exception('Bad alias only git and hg is allowed')

        return other_changesets, org_changesets, ancestors

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def index(self, repo_name):

        c.compare_home = True

        c.a_ref_name = c.cs_ref_name = None

        return render('compare/compare_diff.html')

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def compare(self, repo_name, org_ref_type, org_ref_name, other_ref_type, other_ref_name):

        org_ref_name = org_ref_name.strip()

        other_ref_name = other_ref_name.strip()

        # If merge is True:

        #   Show what org would get if merged with other:

        #   List changesets that are ancestors of other but not of org.

        #   New changesets in org is thus ignored.

        #   Diff will be from common ancestor, and merges of org to other will thus be ignored.

        # If merge is False:

        #   Make a raw diff from org to other, no matter if related or not.

        #   Changesets in one and not in the other will be ignored

        merge = bool(request.GET.get('merge'))

        # fulldiff disables cut_off_limit

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

        # partial uses compare_cs.html template directly

        partial = request.environ.get('HTTP_X_PARTIAL_XHR')

        # is_ajax_preview puts hidden input field with changeset revisions

        c.is_ajax_preview = partial and request.GET.get('is_ajax_preview')

        # swap url for compare_diff page - never partial and never is_ajax_preview

        c.swap_url = h.url('compare_url',

            repo_name=c.cs_repo.repo_name,

            org_ref_type=other_ref_type, org_ref_name=other_ref_name,

            other_repo=c.a_repo.repo_name,

            other_ref_type=org_ref_type, other_ref_name=org_ref_name,

            merge=merge or '')

        # set callbacks for generating markup for icons

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

        ignore_whitespace = request.GET.get('ignorews') == '1'

        line_context = safe_int(request.GET.get('context'), 3)

        c.a_rev = self._get_ref_rev(c.a_repo, org_ref_type, org_ref_name,

            returnempty=True)

        c.cs_rev = self._get_ref_rev(c.cs_repo, other_ref_type, other_ref_name)

        c.compare_home = False

        c.a_ref_name = org_ref_name

        c.a_ref_type = org_ref_type

        c.cs_ref_name = other_ref_name

        c.cs_ref_type = other_ref_type

        c.cs_ranges, c.cs_ranges_org, c.ancestors = self._get_changesets(

            c.a_repo.scm_instance.alias, c.a_repo.scm_instance, c.a_rev,

            c.cs_repo.scm_instance, c.cs_rev)

        raw_ids = [x.raw_id for x in c.cs_ranges]

        c.cs_comments = c.cs_repo.get_comments(raw_ids)

        c.cs_statuses = c.cs_repo.statuses(raw_ids)

        revs = [ctx.revision for ctx in reversed(c.cs_ranges)]

        c.jsdata = graph_data(c.cs_repo.scm_instance, revs)

        if partial:

            return render('compare/compare_cs.html')

        org_repo = c.a_repo

        other_repo = c.cs_repo

        if merge:

            rev1 = msg = None

            if not c.cs_ranges:

                msg = _('Cannot show empty diff')

            elif not c.ancestors:

                msg = _('No ancestor found for merge diff')

            elif len(c.ancestors) == 1:

                rev1 = c.ancestors[0]

            else:

                msg = _('Multiple merge ancestors found for merge compare')

            if rev1 is None:

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

                log.error(msg)

                raise HTTPNotFound

            # case we want a simple diff without incoming changesets,

            # previewing what will be merged.

            # Make the diff on the other repo (which is known to have other_rev)

            log.debug('Using ancestor %s as rev1 instead of %s',

                      rev1, c.a_rev)

            org_repo = other_repo

        else: # comparing tips, not necessarily linearly related

            if org_repo != other_repo:

                # TODO: we could do this by using hg unionrepo

                log.error('cannot compare across repos %s and %s', org_repo, other_repo)

                h.flash(_('Cannot compare repositories without using common ancestor'), category='error')

                raise HTTPBadRequest

            rev1 = c.a_rev

        diff_limit = None if fulldiff else self.cut_off_limit

        log.debug('running diff between %s and %s in %s',

                  rev1, c.cs_rev, org_repo.scm_instance.path)

                                      ignore_whitespace=ignore_whitespace,

                                      context=line_context)

        diff_processor = diffs.DiffProcessor(raw_diff or '', diff_limit=diff_limit)

        c.limited_diff = diff_processor.limited_diff

        c.file_diff_data = []

        c.lines_added = 0

        c.lines_deleted = 0

        for f in diff_processor.parsed:

            st = f['stats']

            c.lines_added += st['added']

            c.lines_deleted += st['deleted']

            filename = f['filename']

            fid = h.FID('', filename)

            html_diff = diffs.as_html(enable_comments=False, parsed_lines=[f])

            c.file_diff_data.append((fid, None, f['operation'], f['old_filename'], filename, html_diff, st))

        return render('compare/compare_diff.html')

        new_reviewers = set(_get_reviewer(s) for s in _form['review_members'])

        old_reviewers = set(_get_reviewer(s) for s in _form['org_review_members'])

        other_added = cur_reviewers - old_reviewers

        other_removed = old_reviewers - cur_reviewers

        if other_added:

            h.flash(_('Meanwhile, the following reviewers have been added: %s') %

                    (', '.join(u.username for u in other_added)),

                    category='warning')

        if other_removed:

            h.flash(_('Meanwhile, the following reviewers have been removed: %s') %

                    (', '.join(u.username for u in other_removed)),

                    category='warning')

        if _form['updaterev']:

            return self.create_new_iteration(pull_request,

                                      _form['updaterev'],

                                      _form['pullrequest_title'],

                                      _form['pullrequest_desc'],

                                      new_reviewers)

        added_reviewers = new_reviewers - old_reviewers - cur_reviewers

        removed_reviewers = (old_reviewers - new_reviewers) & cur_reviewers

        old_description = pull_request.description

        pull_request.title = _form['pullrequest_title']

        pull_request.description = _form['pullrequest_desc'].strip() or _('No description')

        pull_request.owner = User.get_by_username(_form['owner'])

        user = User.get(request.authuser.user_id)

        PullRequestModel().mention_from_description(user, pull_request, old_description)

        PullRequestModel().add_reviewers(user, pull_request, added_reviewers)

        PullRequestModel().remove_reviewers(user, pull_request, removed_reviewers)

        Session().commit()

        h.flash(_('Pull request updated'), category='success')

        raise HTTPFound(location=pull_request.url())

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def delete(self, repo_name, pull_request_id):

        pull_request = PullRequest.get_or_404(pull_request_id)

        # only owner can delete it !

        if pull_request.owner_id == request.authuser.user_id:

            PullRequestModel().delete(pull_request)

            Session().commit()

            h.flash(_('Successfully deleted pull request'),

                    category='success')

            raise HTTPFound(location=url('my_pullrequests'))

        raise HTTPForbidden()

    @LoginRequired()

    @HasRepoPermissionLevelDecorator('read')

    def show(self, repo_name, pull_request_id, extra=None):

        repo_model = RepoModel()

        c.users_array = repo_model.get_users_js()

        c.user_groups_array = repo_model.get_user_groups_js()

        c.pull_request = PullRequest.get_or_404(pull_request_id)

        c.allowed_to_change_status = self._get_is_allowed_change_status(c.pull_request)

        cc_model = ChangesetCommentsModel()

        cs_model = ChangesetStatusModel()

        # pull_requests repo_name we opened it against

        # ie. other_repo must match

        if repo_name != c.pull_request.other_repo.repo_name:

            raise HTTPNotFound

        # load compare data into template context

        c.cs_repo = c.pull_request.org_repo

        (c.cs_ref_type,

         c.cs_ref_name,

         c.cs_rev) = c.pull_request.org_ref.split(':')

        c.a_repo = c.pull_request.other_repo

        (c.a_ref_type,

         c.a_ref_name,

         c.a_rev) = c.pull_request.other_ref.split(':') # a_rev is ancestor

        org_scm_instance = c.cs_repo.scm_instance # property with expensive cache invalidation check!!!

        try:

            c.cs_ranges = []

            for x in c.pull_request.revisions:

                c.cs_ranges.append(org_scm_instance.get_changeset(x))

        except ChangesetDoesNotExistError:

            c.cs_ranges = []

            h.flash(_('Revision %s not found in %s') % (x, c.cs_repo.repo_name),

                'error')

        c.cs_ranges_org = None # not stored and not important and moving target - could be calculated ...

        revs = [ctx.revision for ctx in reversed(c.cs_ranges)]

        c.jsdata = graph_data(org_scm_instance, revs)

        c.is_range = False

        try:

            if c.a_ref_type == 'rev': # this looks like a free range where target is ancestor

                cs_a = org_scm_instance.get_changeset(c.a_rev)

                root_parents = c.cs_ranges[0].parents

                c.is_range = cs_a in root_parents

                #c.merge_root = len(root_parents) > 1 # a range starting with a merge might deserve a warning

        except ChangesetDoesNotExistError: # probably because c.a_rev not found

            pass

        except IndexError: # probably because c.cs_ranges is empty, probably because revisions are missing

            pass

        avail_revs = set()

        avail_show = []

        c.cs_branch_name = c.cs_ref_name

        c.a_branch_name = None

        other_scm_instance = c.a_repo.scm_instance

        c.update_msg = ""

        c.update_msg_other = ""

        try:

            if not c.cs_ranges:

                c.update_msg = _('Error: changesets not found when displaying pull request from %s.') % c.cs_rev

            elif org_scm_instance.alias == 'hg' and c.a_ref_name != 'ancestor':

                if c.cs_ref_type != 'branch':

                    c.cs_branch_name = org_scm_instance.get_changeset(c.cs_ref_name).branch # use ref_type ?

                c.a_branch_name = c.a_ref_name

                if c.a_ref_type != 'branch':

                    try:

                        c.a_branch_name = other_scm_instance.get_changeset(c.a_ref_name).branch # use ref_type ?

                    except EmptyRepositoryError:

                        c.a_branch_name = 'null' # not a branch name ... but close enough

                # candidates: descendants of old head that are on the right branch

                #             and not are the old head itself ...

                #             and nothing at all if old head is a descendant of target ref name

                if not c.is_range and other_scm_instance._repo.revs('present(%s)::&%s', c.cs_ranges[-1].raw_id, c.a_branch_name):

                    c.update_msg = _('This pull request has already been merged to %s.') % c.a_branch_name

                elif c.pull_request.is_closed():

                    c.update_msg = _('This pull request has been closed and can not be updated.')

                else: # look for descendants of PR head on source branch in org repo

                    avail_revs = org_scm_instance._repo.revs('%s:: & branch(%s)',

                                                             revs[0], c.cs_branch_name)

                    if len(avail_revs) > 1: # more than just revs[0]

                        # also show changesets that not are descendants but would be merged in

                        targethead = other_scm_instance.get_changeset(c.a_branch_name).raw_id

                        if org_scm_instance.path != other_scm_instance.path:

                            # Note: org_scm_instance.path must come first so all

                            # valid revision numbers are 100% org_scm compatible

                            # - both for avail_revs and for revset results

                            hgrepo = unionrepo.unionrepository(org_scm_instance.baseui,

                                                               org_scm_instance.path,

                                                               other_scm_instance.path)

                        else:

                            hgrepo = org_scm_instance._repo

                        show = set(hgrepo.revs('::%ld & !::parents(%s) & !::%s',

                                               avail_revs, revs[0], targethead))

                        c.update_msg = _('The following additional changes are available on %s:') % c.cs_branch_name

                    else:

                        show = set()

                        avail_revs = set() # drop revs[0]

                        c.update_msg = _('No additional changesets found for iterating on this pull request.')

                    # TODO: handle branch heads that not are tip-most

                    brevs = org_scm_instance._repo.revs('%s - %ld - %s', c.cs_branch_name, avail_revs, revs[0])

                    if brevs:

                        # also show changesets that are on branch but neither ancestors nor descendants

                        show.update(org_scm_instance._repo.revs('::%ld - ::%ld - ::%s', brevs, avail_revs, c.a_branch_name))

                        show.add(revs[0]) # make sure graph shows this so we can see how they relate

                        c.update_msg_other = _('Note: Branch %s has another head: %s.') % (c.cs_branch_name,

                            h.short_id(org_scm_instance.get_changeset((max(brevs))).raw_id))

                    avail_show = sorted(show, reverse=True)

            elif org_scm_instance.alias == 'git':

                c.cs_repo.scm_instance.get_changeset(c.cs_rev) # check it exists - raise ChangesetDoesNotExistError if not

                c.update_msg = _("Git pull requests don't support iterating yet.")

        except ChangesetDoesNotExistError:

            c.update_msg = _('Error: some changesets not found when displaying pull request from %s.') % c.cs_rev

        c.avail_revs = avail_revs

        c.avail_cs = [org_scm_instance.get_changeset(r) for r in avail_show]

        c.avail_jsdata = graph_data(org_scm_instance, avail_show)

        raw_ids = [x.raw_id for x in c.cs_ranges]

        c.cs_comments = c.cs_repo.get_comments(raw_ids)

        c.cs_statuses = c.cs_repo.statuses(raw_ids)

        ignore_whitespace = request.GET.get('ignorews') == '1'

        line_context = safe_int(request.GET.get('context'), 3)

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

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

        diff_limit = None if fulldiff else self.cut_off_limit

        # we swap org/other ref since we run a simple diff on one repo

        log.debug('running diff between %s and %s in %s',

                  c.a_rev, c.cs_rev, org_scm_instance.path)

        try:

        except ChangesetDoesNotExistError:

            raw_diff = _("The diff can't be shown - the PR revisions could not be found.")

        diff_processor = diffs.DiffProcessor(raw_diff or '', diff_limit=diff_limit)

        c.limited_diff = diff_processor.limited_diff

        c.file_diff_data = []

        c.lines_added = 0

        c.lines_deleted = 0

        for f in diff_processor.parsed:

            st = f['stats']

            c.lines_added += st['added']

            c.lines_deleted += st['deleted']

            filename = f['filename']

            fid = h.FID('', filename)

            html_diff = diffs.as_html(enable_comments=True, parsed_lines=[f])

            c.file_diff_data.append((fid, None, f['operation'], f['old_filename'], filename, html_diff, st))

        # inline comments

        c.inline_cnt = 0

        c.inline_comments = cc_model.get_inline_comments(

                                c.db_repo.repo_id,

                                pull_request=pull_request_id)

        # count inline comments

        for __, lines in c.inline_comments:

            for comments in lines.values():

                c.inline_cnt += len(comments)

        # comments

        c.comments = cc_model.get_comments(c.db_repo.repo_id, pull_request=pull_request_id)

        # (badly named) pull-request status calculation based on reviewer votes

        (c.pull_request_reviewers,

         c.pull_request_pending_reviewers,

         c.current_voting_result,

         ) = cs_model.calculate_pull_request_result(c.pull_request)

        c.changeset_statuses = ChangesetStatus.STATUSES

        c.is_ajax_preview = False

        c.ancestors = None # [c.a_rev] ... but that is shown in an other way

        return render('/pullrequests/pullrequest_show.html')

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionLevelDecorator('read')

    @jsonify

    def comment(self, repo_name, pull_request_id):

        pull_request = PullRequest.get_or_404(pull_request_id)

        status = request.POST.get('changeset_status')

        close_pr = request.POST.get('save_close')

        delete = request.POST.get('save_delete')

        f_path = request.POST.get('f_path')

        line_no = request.POST.get('line')

        if (status or close_pr or delete) and (f_path or line_no):

            # status votes and closing is only possible in general comments

            raise HTTPBadRequest()

        allowed_to_change_status = self._get_is_allowed_change_status(pull_request)

        if not allowed_to_change_status:

            if status or close_pr:

                h.flash(_('No permission to change pull request status'), 'error')

                raise HTTPForbidden()

        if delete == "delete":

            if (pull_request.owner_id == request.authuser.user_id or

                h.HasPermissionAny('hg.admin')() or

                h.HasRepoPermissionLevel('admin')(pull_request.org_repo.repo_name) or

                h.HasRepoPermissionLevel('admin')(pull_request.other_repo.repo_name)

                ) and not pull_request.is_closed():

                PullRequestModel().delete(pull_request)

                Session().commit()

                h.flash(_('Successfully deleted pull request %s') % pull_request_id,

                        category='success')

                return {

                   'location': url('my_pullrequests'), # or repo pr list?

                }

                raise HTTPFound(location=url('my_pullrequests')) # or repo pr list?

            raise HTTPForbidden()

        text = request.POST.get('text', '').strip()