[fpc-devel] TEncoding.Default and default encoding for TStrings.LoadFrom*()
lazarus at kluug.net
Fri Dec 27 02:20:56 CET 2019
On 26.12.2019 23:42, Marco van de Voort wrote:
> Op 12/26/2019 om 9:12 PM schreef Ondrej Pokorny:
>> In Delphi TEncoding.ANSI and TEncoding.Default are actually
>> different. See:
>> On Windows, they are equal but on POSIX they are different:
>> TEncoding.Default is UTF-8 but TEncoding.ANSI is the code page from
> And in FPC it is exactly the same,
No, it is not. In FPC:
class function TEncoding.GetDefault: TEncoding;
Result := GetANSI;
For the meaning of TEncoding.Default and TEncoding.ANSI in Delphi see
the docs above.
> BUT Lazarus overrides default with UTF8 on Windows.
Yes, it does it since r61976 - so only recently. And it is a very
questionable commit because
a) is not Delphi compatible
b) breaks OS-ANSI calls
c) breaks ANSI FPC code
It must either be reverted or we need some high-level method to get the
OS-ANSI codepage without this override.
> As you can see that is NOT compatible with Delphi above.
Yes, and I am against r61976 - but because r61976 overrides
TEncoding.ANSI to UTF-8 on Windows. IMO TEncoding.Default should be
UTF-8 in Lazarus even on Windows (whereas TEncoding.ANSI should stay
OS-ANSI) - I try to explain again why this actually fits very well into
the Delphi/FPC encoding concept. I will now talk only about Windows for
simplicity (because the ANSI concept is most important on Windows):
Delphi doesn't know the DefaultSystemEncoding concept that FPC has. The
default AnsiString encoding in Delphi is always OS-ANSI (CP_ACP).
Therefore it makes perfect sense to have TEncoding.Default to point to
the default AnsiString encoding that is OS-ANSI encoding in Delphi.
FPC, on the contrary, overrides the CP_ACP value with
DefaultSystemEncoding. So the default AnsiString encoding is not OS-ANSI
but DefaultSystemEncoding. Therefore, again, it makes perfect sense to
have TEncoding.Default to point to the default AnsiString encoding that
is DefaultSystemEncoding in FPC.
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