Re: BUG #18219: libpq does not take into consideration UNICODE define

On Fri, Dec 1, 2023 at 4:50 AM PG Bug reporting form
<noreply(at)postgresql(dot)org> wrote:
> I use libpqxx via vcpkg in Windows project build for x64 system using Visual
> Studio. There is a UNICODE define, which causes **W Windows functions to be
> used and hence string parameters should be passed in using L"...".
> I have sslrootcert file used in my connection string. During the connection
> initialization stat() function is invoked for the file. It is implemented in
> win32stat.c, which then invokes pgwin32_open_handle() (open.c) and then
> initialize_ntdll() (win32ntdll.c) is invoked. There is a use of
> LoadLibraryEx which is just a define above LoadLibraryExA or LoadLibraryExW.
> Using UNICODE implies LoadLibraryExW to be used, but the parameter passed in
> is char*, not wchar_t*. This leads to failed initialization returning error
> code 126 - The specified module could not be found.
> There should be a switch if UNICODE is defined, then L"ntdll.dll" should be
> passed in. The same applies to all other Windows functions consuming
> strings.

I don't understand vcpkg so I don't even know where to look, but who
defined UNICODE when building libpq?