[fpc-pascal] StringList encoding question

[Bart]

Hi,

Consider this code:

{$codepage utf8}
{$mode objfpc}
{$H+}

uses
  SysUtils, Classes;

var
  SL: TSTringList;
  S: String;

begin
  writeln('DefaultSystemCodePage = ',DefaultSystemCodePage);
  SL := TStringList.Create;
  {$if fpc_fullversion > 30200}
  SL.WriteBom := False;
  {$endif}
  SL.SkipLastLineBreak := True;
  S := 'ä';  //S has CodePage CP_UTF8
  SL.Add(S);
  SL.SaveToFile('slU.txt'{$if fpc_fullversion > 30200}, TEncoding.UTF8{$endif});
  SL.SaveToFile('slA.txt'{$if fpc_fullversion > 30200}, TEncoding.ANSI{$endif});
  SL.Free;
end.

Tested with fpc trunk (form a few days ago).
It outputs:
DefaultSystemCodePage = 1252 (I'm on Windows as you might have guessed)
The file slA.txt contains the bytes C3 A4 (which is ä in UTF8 encoding)
The file slU.txt contains the bytes C3 83 C2 A4

I struggle to understand why.
What is the codepage of the stringlist's internal list of strings
(array of TStringItem's)?
It seems that the stringlist considers it's internal
TStringItem.FString that has #$C3A#$A4 to  have a codepage of CP_ACP
(always)?

Bart

-- 
Bart