[fpc-devel] TEncoding.Default and default encoding for TStrings.LoadFrom*()

[Ondrej Pokorny]

On 26.12.2019 16:41, Mattias Gaertner via fpc-devel wrote:
> On Thu, 26 Dec 2019 16:15:03 +0100
> Ondrej Pokorny <lazarus at kluug.net> wrote:
>
>> Hello,
>>
>> a lot of people have a problem with the TStrings.LoadFrom*() changes
>> when TEncoding support was added.
>>
>> Currently, the no-encoding overloads of TStrings.LoadFrom*() and
>> TStrings.SaveTo*() use the TEncoding.Default, which is WIN-ANSI and
>> not DefaultSystemCodePage.
> It seems FPC 3.3.1 does use DefaultSystemCodePage:
>
> class function TEncoding.GetANSI: TEncoding;
> begin
>    ....
>      if not Assigned(FStandardEncodings[seAnsi]) then
>      begin
>        // DefaultSystemCodePage can be set to non-ANSI
>        if Assigned(widestringmanager.GetStandardCodePageProc) then
>          FStandardEncodings[seAnsi] := TMBCSEncoding.Create(widestringmanager.GetStandardCodePageProc(scpAnsi))
>        else
>          FStandardEncodings[seAnsi] := TMBCSEncoding.Create(DefaultSystemCodePage);
>     ...
> end;

Check the code more carefully. It uses DefaultSystemCodePage only when 
no widestringmanager is present - which is basically never the case (at 
least on win32, Linux, Mac OS).

It uses widestringmanager.GetStandardCodePageProc(scpAnsi) that is 
WIN-ANSI on win32 (typically 1250, 1251, 1252 - depending on your OS 
language version).

Ondrej