anchor.diff:    if HasExtraField then begin
       { get length of extra data }
       AStream.Read(LenW, SizeOf(Word));
  -    SetLength(FExtraField, LenW);
  -    AStream.Read(FExtraField[1], LenW);
  +    SetLength(FExtraField.FBuffer, LenW);
  +    AStream.Read(FExtraField.FBuffer[0], LenW);
     end
     else
  -    FExtraField := '';
  +    FExtraField.FBuffer := nil;
   
     { Get Filename, if any }
     if HasFileName then begin
  
positive.code: {$ENDIF MSWINDOWS }
  end;
  
  function TAbGzipItem.GetExternalFileAttributes: LongInt;
  begin
    { GZip has no provision for storing attributes }
  
negative.code: 
    FileName := '';
    FFileComment := '';
    FExtraField := TAbGzipExtraField.Create(@FGzHeader);
  
    { source OS ID }
  {$IFDEF LINUX } {assume EXT2 system }
  