serde_json::from_slice serialize empty array error

[baoyachi]

fn main() {
    let buf = vec![];
    let x:serde_json::Value = serde_json::from_slice(&buf).unwrap();
    println!("{:?}",x);
}

expected value：Null, But now, the code serialize error

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error("EOF while parsing a value", line: 1, column: 0)', src/main.rs:3:60

playground: link

[dtolnay]

This is behaving correctly, since is not valid JSON.