Function with_tmp_xdg

crates/openshell-cli/src/main.rs:3202–3217

(tmp: &std::path::Path, f: F)

    /// then restore the original value.
    #[allow(unsafe_code)]
    fn with_tmp_xdg<F: FnOnce()>(tmp: &std::path::Path, f: F) {
        let _guard = XDG_LOCK
            .lock()
            .unwrap_or_else(std::sync::PoisonError::into_inner);
        let orig = std::env::var("XDG_CONFIG_HOME").ok();
        unsafe {
            std::env::set_var("XDG_CONFIG_HOME", tmp);
        }
        f();
        unsafe {
            match orig {
                Some(v) => std::env::set_var("XDG_CONFIG_HOME", v),
                None => std::env::remove_var("XDG_CONFIG_HOME"),
            }
        }
    }

    fn edge_metadata(name: &str, endpoint: &str) -> GatewayMetadata {
        GatewayMetadata {