def create_revision(bustopic, title, content, summary,request):
revision = ArticleRevision()
revision.inherit_predecessor(bustopic.article)
if not title:
revision.title=bustopic.article.current_revision.title
else:
revision.title = title
revision.content = content
revision.user_message = summary
revision.deleted = False
revision.set_from_request(request)
revision.save()
return revision
