anchor.diff:        read FExtraField write SetExtraField;
   
       property HeaderCRC : Word
  -      read GetHeaderCRC;
  +      read FCRC16;
   
       property IsEncrypted : Boolean
         read GetIsEncrypted;
  
positive.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);
  
negative.code:     FFileComment := '';
  
    { any 16-bit CRC for header present? }
    if HasHeaderCRC then
      AStream.Read(FCRC16, SizeOf(FCRC16))
    else
      FCRC16 := 0;
  
    {Assert: stream should now be located at start of compressed data }
    {If file was compressed with 3.3 spec this will be invalid so use with care}
  