Getting a free cell after clock advances

[alpeb]

Hi, I'm wondering if this is expected behavior (and if so, what's the reasoning behind it) or a bug?

Here's a repro describing my issue:

• Set a direct rate-limiter with a max_burst of 5
• Consume that quota and verify another cell is not allowed
• Advance time a couple of seconds
• Now 6 cells are allowed?

#[test]
fn free_cell() {
    let clock = FakeRelativeClock::default();
    let rl = RateLimiter::direct_with_clock(Quota::per_second(nonzero!(5u32)), clock.clone());

    // consume the rate-limiter
    for _ in 1..=5 {
        assert!(rl.check().is_ok());
    }
    assert!(rl.check().is_err());

    // advance the clock
    clock.advance(Duration::from_secs(2));

    // Now I can get in one more extra cell
    for _ in 1..=6 {
        assert!(rl.check().is_ok());
    }

    assert!(rl.check().is_err());
}

Perhaps the same issue as #107?

Thanks!