https://bugs.winehq.org/show_bug.cgi?id=45320
--- Comment #3 from Dima Ryazanov dima@gmail.com --- Jason: wow, you're correct.
I ran Example 3 from https://msdn.microsoft.com/en-us/library/windows/desktop/ms682009(v=vs.85).a... ; it uses GetEnvironmentStrings to print out environment variables.
On Wine, it produces exactly the same output as my testcase. On Windows, however, I see three extra variables:
=::=::\ =C:=C:\Users\dima\Documents =ExitCode=00000000
So looks like they're just hidden from the POSIX APIs?