BUG: pkg-config metadata is incorrect on windows

[h-vetinari]

What version of protobuf and what language are you using?
Version: v29.1 (but problem remains on main)
Language: C++

What operating system (Linux, Windows, ...) and version?

windows

What runtime / compiler are you using (e.g., python version or gcc version)

VS2019

What did you do?

Build protobuf, try to use pkg-config metadata in dependent project

What did you expect to see

Build succeeds

What did you see instead?

LINK : fatal error LNK1181: cannot open input file 'upb.lib'

This is because the windows builds here have a non-default prefix (e.g. libprotobuf.lib instead of protobuf.lib), and so the linker invocation here

protobuf/cmake/upb.pc.cmake

Line 9 in 796e49f

Libs: -L${libdir} -lupb @CMAKE_THREAD_LIBS_INIT@

is actually looking for the wrong library (upb.lib instead of the libupb.lib that gets installed). Since %INSTALL_PREFIX%\lib\pkgconfig\upb.pc gets installed by default, it should be correct.

Anything else we should know about your project / environment

The error does not appear with CMake, but there's several more pkg-config files that have the same problem AFAICT.