[fpc-devel] TEncoding.Default and default encoding for TStrings.LoadFrom*()
lazarus at kluug.net
Thu Dec 26 16:15:03 CET 2019
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
Before the changes, the encoding was just ignored and the file was read
without any codepage support (thus in fact in DefaultSystemCodePage).
A lot of people have a problem with it because in Lazarus they used to
read UTF-8 text with TStrings.LoadFrom*(). Now the text is broken
because TStrings.LoadFrom*() load the text in WIN-ANSI.
The Lazarus team came with some kind of solution: they changed the FPC
internal function widestringmanager.GetStandardCodePageProc to return
UTF-8 and thus TEncoding.Default and TEncoding.ANSI to be UTF-8. This,
as a result, broke every ANSI code that needs real WIN-ANSI codepage
(like the ODBC: https://bugs.freepascal.org/view.php?id=36481 ). (And it
introduced more Delphi & other Lazarus incompatibilities just for the
sake of keeping TStrings.LoadFrom*() legacy-Lazarus compatible.)
For me the Lazarus solution is not acceptable.
But other Lazarus team members seem not to be happy with the encoding
breaking change in FPC TStrings.LoadFrom*() and SaveTo*() and ask for a
I suggest a compromise (steps):
1.) Keep TEncoding.ANSI always WIN-ANSI and Delphi-compatible. (Don't
change it to DefaultSystemCodePage in Lazarus.)
2.) Change TEncoding.Default value to current TEncoding.SystemEncoding.
I.e. TEncoding.Default would correspond to DefaultSystemCodePage and
CP_ACP. Yes, this will be Delphi-incompatible - but CP_ACP is
Delphi-incompatible as well (!) - so the incompatibilities are
3.) Delete TEncoding.SystemEncoding because it is an FPC-only construct,
it is not needed anymore (because it will become TEncoding.Default) and
it has not been released in any stable version.
The above steps perfectly correlate with the CP_ACP value corresponding
to DefaultSystemEncoding. As I wrote before, the CP_ACP is not
Delphi-compatible either. See
It makes perfect sense to keep TEncoding consequent with CP_ACP and make
TEncoding.Default to correspond with DefaultSystemEncoding.
It is also natural: I would expect TEncoding.Default to correspond with
the default (Ansi)String encoding, which is DefaultSystemEncoding.
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