OsString values are incorrectly NULL-terminated

[xobs]

According to https://doc.rust-lang.org/std/ffi/struct.OsString.html, OsString objects should not be NULL terminated:

OsString and OsStr bridge this gap by simultaneously representing Rust and platform-native string values, and in particular allowing a Rust string to be converted into an “OS” string with no cost if possible. A consequence of this is that OsString instances are not NUL terminated; in order to pass to e.g., Unix system call, you should create a CStr.

However, winreg produces strings that have a NULL terminator:

use std::io;
use std::ffi::OsString;
use winreg::enums::*;
use winreg::RegKey;

fn main() -> io::Result<()> {
    println!("Reading some system info...");
    let hklm = RegKey::predef(HKEY_LOCAL_MACHINE);
    let cur_ver = hklm.open_subkey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion")?;
    let pf: OsString = cur_ver.get_value("ProgramFilesDir")?;
    println!("Program files dir");
    use std::os::windows::ffi::OsStrExt;
    for c in pf.encode_wide() {
        print!(" {:02x}", c);
    }
    println!();

    Ok(())
}

Running this produces:

❯ cargo run
   Compiling winreg-test v0.1.0 (C:\Users\smcro\Code\Ion\winreg-test)
    Finished dev [unoptimized + debuginfo] target(s) in 0.45s
     Running `target\debug\winreg-test.exe`
Reading some system info...
Program files dir
 43 3a 5c 50 72 6f 67 72 61 6d 20 46 69 6c 65 73 00
❯