anchor.diff:      #db{
           fulldocinfo_by_id_btree = DocInfoByIdBTree,
           docinfo_by_seq_btree = DocInfoBySeqBTree,
  -        update_seq = LastSeq
  +        update_seq = LastSeq,
  +        revs_limit = RevsLimit
           } = Db,
       Ids = [Id || [{_Client, #doc{id=Id}}|_] <- DocsList],
       % lookup up the old documents, if they exist.
  
positive.code:             end
          end,
          OldTree, NewDocs),
      if NewRevTree == OldTree ->
          % nothing changed
          merge_rev_trees(MergeConflicts, RestDocsList, RestOldInfo, AccNewInfos,
                  AccRemoveSeqs, AccSeq);
      true ->
          % we have updated the document, give it a new seq #
          NewInfo = #full_doc_info{id=Id,update_seq=AccSeq+1,rev_tree=NewRevTree},
  
negative.code:         end,
          Ids, OldDocLookups),
      % Merge the new docs into the revision trees.
      {ok, NewFullDocInfos, RemoveSeqs, NewSeq} = merge_rev_trees(RevsLimit,
              MergeConflicts, DocsList, OldDocInfos, [], [], LastSeq),
  
      % All documents are now ready to write.
  
  