theoretically bug in db.set method?

[qyuzh]

theoretically bug in db.set method when current expire equal previous.

Is this code Better?

        if let Some(prev) = prev {
            if let Some(when) = prev.expires_at {
                if expires_at.is_none() || when != expires_at.unwrap() {
                    state.expirations.remove(&(when, key));
                }
            }
        }

than

        if let Some(prev) = prev {
            if let Some(when) = prev.expires_at {
                // clear expiration
                state.expirations.remove(&(when, key));
            }
        }

[Darksonn]

Nice catch. I somewhat prefer to swap their order so that we remove first, and then insert.

[qyuzh]

I opened a PR, help me review it please.