anchor.diff:  
   function TAbGzipArchive.CreateItem(const FileSpec: string): TAbArchiveItem;
   var
  -  Buff : array [0..511] of Char;
     GzItem : TAbGzipItem;
   begin
     if IsGZippedTar and TarAutoHandle then begin
  -    if FState <> gsTar then
  -      SwapToTar;
  +    SwapToTar;
       Result := inherited CreateItem(FileSpec);
     end
     else begin
  
positive.code:     try
        GzItem.CompressedSize := 0;
        GzItem.CRC32 := 0;
        StrPCopy(Buff, ExpandFileName(FileSpec));
        GzItem.DiskFileName := StrPas(Buff);
        StrPCopy(Buff, FixName(FileSpec));
        GzItem.FileName := StrPas(Buff);
        Result := GzItem;
      except
        Result := nil;
  
negative.code: procedure TAbGzipItem.SetIsText(const Value: Boolean);
  begin
    FIsText := Value;
    if Value then
      FGzHeader.Flags := FGzHeader.Flags or AB_GZ_FLAG_FTEXT
    else
      FGzHeader.Flags := FGzHeader.Flags and not AB_GZ_FLAG_FTEXT;
  end;
  
  procedure TAbGzipItem.SetLastModFileDate(const Value: Word);
  