BOLT2: both nodes send update_add_htlc

[nayuta-ueno]

issue #472

In this sequence, three commitment_signed and revoke_and_ack are required.

[TheBlueMatt]

This should not be the case. When B sends A a commitment_signed it should absolutely include any pending update_adds from B.

[nayuta-ueno]

@TheBlueMatt

When B sends A a commitment_signed it should absolutely include any pending update_adds from B.

When B receive revoke_and_ack(7), B have signed commitment transaction HTLC1, 2 (HTLC3 has only applied).
Therefore 'A' need sends commitment_singed(8) like #472 .

[pm47]

@nayuta-ueno is right, A acknowledges the incoming htlc (3) at step (7), only then will this hltlc be signed by A.

[nayuta-ueno]

@pm47 Thank you for your review!
(I'm not @ ueno but @nayuta-ueno :)

[TheBlueMatt]

Oops, oops, yes, you're right, I'd missed the direction of the last HTLC.

[rustyrussell]

You are correct, the example was unclear. Perhaps deliberately so, as below it says:

what matters is whether both sides have irrevocably committed to a
particular HTLC or not (the final state, above).

Which implies that it's deliberate that one side is committed to the HTLC and the other isn't? We should probably spell out the states at each point for each side, but that's a separate commit.