`Ct1Ack` is defined in the spec but doesn't seem to be emitted

[astefano]

Hi,

continuing with the thread from #4, here the second discrepancy:

2. Ct1Ack is defined in the spec but it is not emitted; code adds undocumented behavior

2a. EkSentCt1Received.Send — spec sends None, code sends Ct1Ack

Spec (page 15, EkSentCt1Received.Send):

msg = {epoch: state.epoch, type: None}

Code (src/v1/chunked/states.rs:178–183):

Self::EkSentCt1Received(state) => {
    let epoch = state.epoch();
    Ok(Send {
        state: Self::EkSentCt1Received(state),
        msg: Message { epoch, payload: MessagePayload::Ct1Ack(true) },
        key: None,
    })
}

2b. EkReceivedCt1Sampled.Receive — spec accepts only EkCt1Ack, code also accepts Ct1Ack

Spec (page 20–21, EkReceivedCt1Sampled.Receive):

if msg.epoch == state.epoch and msg.type == EkCt1Ack:
    # Transition (12) → Ct2Sampled

Code (src/v1/chunked/states.rs:464–467):

if matches!(msg.payload, MessagePayload::Ct1Ack(true) | MessagePayload::EkCt1Ack(_)) {
    Self::Ct2Sampled(state.recv_ct1_ack(msg.epoch))
}

2c. §2.3 defines Ct1Ack but no Send function in §2.5 produces it

§2.3 lists Ct1Ack as a message type ("No payload, but the sender has completely received ct1"). But inspecting the Send functions in §2.5 we don't see any emitting Ct1Ack message.