runtime: SpecialFolder.MyDocuments / Personal returning wrong path for Unix

Description

Using Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) (and by extensions also SpecialFolder.Personal) on Unix based systems does not return the documents folder, and instead returns the same path as Environment.GetFolderPath(Environment.SpecialFolder.UserProfile).

Reproduction Steps

Console.WriteLine("Environment.SpecialFolder.MyDocuments:");
Console.WriteLine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));
Console.WriteLine("Environment.SpecialFolder.UserProfile:");
Console.WriteLine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile));

Expected behavior

Since Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) should return the directory that serves as a common repository for documents, it should report the directory I have set via xdg-users-dir / XDG_DOCUMENTS_DIR or ~/Documents on Mac.

Actual behavior

It reports my home directory instead. Comparison between Linux and Windows:

Checking this it seems that it’s intentional. Why doesn’t it just use ReadXdgDirectory(home, "XDG_DOCUMENTS_DIR", "Documents"); there? I can do a PR if it’s wished for.

Regression?

No response

Known Workarounds

No response

Configuration

Dotnet version: 6.0.101 Can reproduce on the following distros: Arch Linux WSL2, Ubuntu 20.04 WSL2, Arch Linux, macOS Big Sur Architecture: x64

Other information

No response