[fpc-devel] TRegistry and Unicode

[Michael Van Canneyt]

On Tue, 26 Feb 2019, Yuriy Sydorov wrote:

> On 25.02.2019 20:03, Bart wrote:
>> On Lazarus, this no problem, since by default all strings are UTF8
>> encoded, so all conversions are lossless.
>> 
>> In a plain fpc program though on Windows, default encoding is the
>> current codepage (cp1252 in my case) and information will get lost
>> when you process the result further.
>
> If you just recompile unmodified non-unicode app for Windows, string data 
> loss is imminent if the data is not encoded 
> using the current ANSI encoding. Even if you use UnicodeString parameters and 
> result for registry functions.
>
> Just adding a single line to the beginning of the app will solve the data 
> loss:
> DefaultSystemCodePage:=CP_UTF8;
>
> I would leave the registry parameters and results as "string" as it is done 
> in other parts of RTL/FCL.
> For performance critical functions it is possible to add an overloaded 
> versions of functions which accepts UnicodeString 
> parameters. IMO the registry access is not the time critical.

My proposal exactly.

But inner workings can be made to use Unicode, because the underlying APIs
are using unicode: The *W registry calls on windows, XML DOM on other systems.

Michael.