anchor.diff:  commit_ext(#commit{ext = []}) -> [];
   commit_ext(#commit{ext = Ext}) ->
       case lists:keyfind(ext_copies, 1, Ext) of
  -	{_, C} ->
  -	    lists:foldl(fun({Ext0, Op}, D) ->
  -				orddict:append(Ext0, Op, D)
  -			end, orddict:new(), C);
  -	false -> []
  +        {_, C} -> C;
  +        false -> []
       end.
   
   update(_Tid, [], _DumperMode) ->
  
positive.code: 	    end
      end,
      D = Rec#commit.disc_copies,
      ExtOps = commit_ext(Rec),
      insert_ops(Tid, disc_copies, D, InPlace, InitBy, LogV),
      [insert_ops(Tid, Ext, Ops, InPlace, InitBy, LogV) ||
  	{Ext, Ops} <- ExtOps,
  	storage_semantics(Ext) == disc_copies],
      case InitBy of
  	startup ->
  	    DO = Rec#commit.disc_only_copies,
  	    insert_ops(Tid, disc_only_copies, DO, InPlace, InitBy, LogV),
  	    [insert_ops(Tid, Ext, Ops, InPlace, InitBy, LogV) ||
  		{Ext, Ops} <- ExtOps, storage_semantics(Ext) == disc_only_copies];
  	_ ->
  	    ignore
      end.
  
negative.code: 	    close_files(InPlace, Error, InitBy),
              fatal("Schema update error ~tp ~tp", [{Reason,ST}, SchemaOps])
      end.
  
  insert_ext_ops(Tid, ExtOps, InPlace, InitBy) ->
    %% Note: ext ops cannot be part of pre-4.3 logs, so there's no need
    %% to support the old operation order, as in `insert_ops'
    lists:foreach(
      fun ({Ext, Op}) ->
          case storage_semantics(Ext) of
            Semantics when Semantics == disc_copies;
                           Semantics == disc_only_copies, InitBy == startup ->
              insert_op(Tid, Ext, Op, InPlace, InitBy);
            _Other ->
              ok
          end
      end,
      ExtOps).
  
  insert_ops(_Tid, _Storage, [], _InPlace, _InitBy, _) ->    ok;
  insert_ops(Tid, Storage, [Op], InPlace, InitBy, Ver)  when Ver >= "4.3"->
  