anchor.diff:              {Res, S#state{count=Count+1}}
       end.
   
  -convert_csum_req(none) ->
  -    #mpb_chunkcsum{type='CSUM_TAG_NONE',
  -                   csum=undefined};
  -convert_csum_req({client_sha, CSumBin}) ->
  +convert_csum_req(none, Chunk) ->
  +    #mpb_chunkcsum{type='CSUM_TAG_CLIENT_SHA',
  +                   csum=machi_util:checksum_chunk(Chunk)};
  +convert_csum_req({client_sha, CSumBin}, _Chunk) ->
       #mpb_chunkcsum{type='CSUM_TAG_CLIENT_SHA',
                      csum=CSumBin}.
   
  
positive.code:         PK = if PlacementKey == <<>> -> undefined;
                  true                 -> PlacementKey
               end,
          CSumT = convert_csum_req(CSum),
          Req = #mpb_appendchunkreq{placement_key=PK,
                                    prefix=Prefix,
                                    chunk=Chunk,
  
negative.code:              #state{sock=Sock, sock_id=Index, count=Count}=S) ->
      try
          ReqID = <<Index:64/big, Count:64/big>>,
          CSumT = convert_csum_req(CSum, Chunk),
          Req = #mpb_writechunkreq{file=File,
                                   offset=Offset,
                                   chunk=Chunk,
  