anchor.diff:  -define(NS_LOG, "ns_log").
   
   get_current_version() ->
  -    {3,0}.
  +    {3,0,1}.
   
   % Allow all keys to be mergable.
   
  
positive.code:              upgrade_config_from_2_2_0_to_2_3_0(Config)];
          {value, {2,3,0}} ->
              [{set, {node, node(), config_version}, {3,0}} |
               upgrade_config_from_2_3_0_to_3_0(Config)]
      end.
  
  upgrade_config_from_1_7_to_1_7_1() ->
  
negative.code:           end, McdConfig),
  
      [{set, McdKey, NewOrUpdatedParams ++ StrippedMcdConfig}].
  
  upgrade_config_from_3_0_to_3_0_1(Config) ->
      ?log_info("Upgrading config from 3.0 to 3.0.1"),
      DefaultConfig = default(),
      do_upgrade_config_from_3_0_to_3_0_1(Config, DefaultConfig).
  
  do_upgrade_config_from_3_0_to_3_0_1(Config, DefaultConfig) ->
      McdKey = {node, node(), memcached},
      {value, DefaultMcdConfig} = ns_config:search([DefaultConfig], McdKey),
      {value, CurrentMcdConfig} = ns_config:search(Config, McdKey),
      EnginesTuple = {engines, _} = lists:keyfind(engines, 1, DefaultMcdConfig),
      NewMcdConfig = lists:keystore(engines, 1, CurrentMcdConfig, EnginesTuple),
      [{set, McdKey, NewMcdConfig}].
  
  search_sub_key(Config, Key, Subkey) ->
      case ns_config:search(Config, Key) of
  