anchor.diff:  
   implementation
   
  +const
  +  cBlockPrefix = '{@VFD_';
  +
   { TVFDFile }
   
   procedure TVFDFile.AddBlock(aposition: integer; ablockid, aformname, ablockdata: string);
  
positive.code:   fb: TVFDFileBlock;
    startmarker, endmarker: string;
    iblock: string;
  
    newsaved: boolean;
  
  begin
    //  Writeln('merging blocks: ');
    newsaved := False;
  
negative.code: function TVFDFile.GetBlocks: integer;
  var
    n: integer;
    s: string;
    startp, endp: integer;
    formname: string;
    bname, startmarker, endmarker: string;
    datablock: string;
    deletelen: integer;
    dropmarker: boolean;
  begin
    FreeBlocks;
    FParsedData := FFileData;
  
    // searching blocks:
    repeat
      bname     := '';
      formname  := '';
      datablock := '';
      s      := cBlockPrefix;
      startp := pos(s, FParsedData);
      if startp > 0 then
      begin
  