anchor.diff:  -spec validate_default_bucket(props(), props()) -> {props(), errors()}.
   validate_default_bucket(Existing, New) ->
       {Good, Bad} = validate(New, [], []),
  -    {merge(Good, Existing), Bad}.
  +    validate_post_merge(merge(Good, Existing), Bad).
   
   %% @private properties in new overwrite those in old
   -spec merge(props(), props()) -> props().
  
positive.code:     has_allow_mult(Bad) andalso has_datatype(Bad).
  
  only_create_if_valid({Good, Bad}, New) ->
      DT = proplists:get_value(datatype, New),
      AM = proplists:get_value(allow_mult, New),
      FP = get_boolean(write_once, New),
  
negative.code: 
  gen_existing() ->
      Defaults = lists:ukeysort(1, riak_core_bucket_type:defaults()),
      ?LET(Special, oneof([gen_valid_mult_dt(), gen_valid_w1c(), gen_valid_consistent(), gen_valid_dvv_lww(), []]),
           lists:ukeymerge(1, lists:ukeysort(1, Special), Defaults)).
  
  gen_maybe_consistent() ->
  