[Lazarus] Breaking change

[Sven Barth]

On 23.07.2017 12:50, Michael Van Canneyt via Lazarus wrote:
> Hello,
> 
> I have fixed bug 28760:
> 
> https://bugs.freepascal.org/view.php?id=28760
> 
> This will cause compilation of win32wsdialogs.pp to fail, in particular in
> 
> class procedure TWin32WSOpenDialog.SetupVistaFileDialog(ADialog:
> IFileDialog; const AOpenDialog: TOpenDialog);
> 
> search for:
> 
>   if InitialDir <> '' then
>   begin
>     if
> Succeeded(SHCreateItemFromParsingName(PWideChar(UTF8ToUTF16(InitialDir)), nil,
> IShellItem, DefaultFolderItem)) then
>       ADialog.SetFolder(DefaultFolderItem);
>   end;
> 
> Directly passing an interface where (T)REFIID is expected, will no
> longer be possible.

I don't think that it was necessary to change (T)REFIID to be a pointer
and thus making COM interface usage unnecessarily more complicated in
Object Pascal:
- Microsoft implicitely defines a REFIID in guiddef.h to always be an
"IN" parameter, by defining it as "const IID &" for C++ code, so it can
never be written to anyway, thus a "constref" would have sufficed (a
"const IID &" in C++ behaves the same as a "IID *" in C or a "constref
x: IID" in FPC)
- aggregates (which is what a TGUID is) are always passed as pointers
for stdcall functions (basically all functions that are related to COM
and thus to REFIID) and also the Win64 ABI anyway, so a mere "TIID"
already behaved correctly for the Windows targets

Regards,
Sven