c.update_msg = _('This pull request can be updated with changes on %s:') % c.cs_branch_name

                else:

                    show = set()

                    c.update_msg = _('No changesets found for updating this pull request.')

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

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

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

        c.avail_revs = avail_revs

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

        c.avail_jsdata = json.dumps(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.statuses = c.cs_repo.statuses(raw_ids)

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

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

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

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

        diff_limit = self.cut_off_limit if not c.fulldiff else None

        # 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)

        txtdiff = org_scm_instance.get_diff(rev1=safe_str(c.a_rev), rev2=safe_str(c.cs_rev),

                                      ignore_whitespace=ignore_whitespace,

                                      context=line_context)

        diff_processor = diffs.DiffProcessor(txtdiff or '', format='gitdiff',

                                             diff_limit=diff_limit)

        _parsed = diff_processor.prepare()

        c.limited_diff = False

        if isinstance(_parsed, LimitedDiffContainer):

            c.limited_diff = True

        c.files = []

        c.changes = {}

        c.lines_added = 0

        c.lines_deleted = 0

        for f in _parsed:

            st = f['stats']

            c.lines_added += st['added']

            c.lines_deleted += st['deleted']

            fid = h.FID('', f['filename'])

            c.files.append([fid, f['operation'], f['filename'], f['stats']])

            htmldiff = diff_processor.as_html(enable_comments=True,

                                              parsed_lines=[f])

            c.changes[fid] = [f['operation'], f['filename'], htmldiff]

        # 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.as_form = False

        c.ancestor = None # there is one - but right here we don't know which

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

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    @jsonify

    def comment(self, repo_name, pull_request_id):

        pull_request = PullRequest.get_or_404(pull_request_id)

        allowed_to_change_status = self._get_is_allowed_change_status(pull_request)

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

        if close_pr:

            text = _('Closing.') + '\n' + text

        comment = ChangesetCommentsModel().create(

            text=text,

            repo=c.db_repo.repo_id,

            user=c.authuser.user_id,

            pull_request=pull_request_id,

            status_change=(ChangesetStatus.get_status_lbl(status)

                           if status and allowed_to_change_status else None),

            closing_pr=close_pr

        )

        action_logger(self.authuser,

                      'user_commented_pull_request:%s' % pull_request_id,

                      c.db_repo, self.ip_addr, self.sa)

        Session().commit()

        if not request.environ.get('HTTP_X_PARTIAL_XHR'):

            return redirect(pull_request.url())

        data = {

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

        }

        if comment is not None:

            c.comment = comment

            data.update(comment.get_dict())

            data.update({'rendered_text':

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

        return data

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    @jsonify

    def delete_comment(self, repo_name, comment_id):

        co = ChangesetComment.get(comment_id)

        if co.pull_request.is_closed():

            #don't allow deleting comments on closed pull request

            raise HTTPForbidden()

        owner = co.author.user_id == c.authuser.user_id

        repo_admin = h.HasRepoPermissionAny('repository.admin')(c.repo_name)

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

            ChangesetCommentsModel().delete(comment=co)

            Session().commit()

            return True

        else:

            raise HTTPForbidden()