This file details various splicing protocol flows. We detail the exact flow of messages for each scenario, and highlight several edge cases that must be correctly handled by implementations.
- Terminology
- Test Vectors
- Successful single splice
- Multiple splices with concurrent
splice_locked - Disconnection with one side sending
commit_sig - Disconnection with both sides sending
commit_sig - Disconnection with one side sending
tx_signatures - Disconnection with both sides sending
tx_signatures - Disconnection with both sides sending
tx_signaturesand channel updates - Disconnection with concurrent
splice_locked - Disconnection after exchanging
tx_signaturesand one side sendscommit_sigfor channel update - Disconnection after exchanging
tx_signaturesand both sides sendcommit_sigfor channel update;revoke_and_acknot received - Disconnection after exchanging
tx_signaturesand both sides sendcommit_sigfor channel update
We call "active commitments" the set of valid commitment transactions to which updates (update_add_htlc, update_fulfill_htlc, update_fail_htlc, update_fail_malformed_htlc, update_fee) must be applied.
While a funding transaction is not locked (ie splice_locked hasn't been exchanged), updates must be valid for all active commitments.
When representing active commitments, we will only draw the corresponding funding transactions for simplicity. The related commitment transaction simply spends that funding transaction.
For example, the following diagram displays the active commitments when we have an unconfirmed splice (FundingTx2a) and 2 RBF attempts for that splice (FundingTx2b and FundingTx2c).
We thus have 4 active commitments:
- the commitment spending
FundingTx1 - the commitments spending each splice transaction (
FundingTx2a,FundingTx2bandFundingTx2c)
+------------+ +-------------+
| FundingTx1 |--------+------>| FundingTx2a |
+------------+ | +-------------+
|
| +-------------+
+------>| FundingTx2b |
| +-------------+
|
| +-------------+
+------>| FundingTx2c |
+-------------+
Peers must always agree on the set of active commitments, otherwise one side will expect signatures that the other side will not send, which will lead to force-closing the channel.
In the protocol flows below, we omit the interactive-tx messages that build the transaction.
The only interactive-tx messages we explicitly list are the consecutive tx_complete that mark the end of the interactive-tx construction.
We also assume that both peers use the same commitment_number for simplicity.
Comprehensive testing should include:
- Splice-in, Splice-out and their sequential combinations.
- Peers that have sufficient balance after the initial funding transaction.
- Peers that have sufficient balance via htlcs.
- Peers with different
commitment_number.
Let's warm up with the simplest possible flow: a splice transaction that confirms without any disconnection. This flow should be tested for different scenarios, such as:
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| tx_signatures |
|<-----------------------------|
| | The channel is no longer quiescent at that point.
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| update_add_htlc | Alice and Bob use the channel while the splice transaction is unconfirmed.
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 2
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| start_batch | batch_size = 2
|<-----------------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| splice_locked | The splice transaction confirms.
|----------------------------->|
| splice_locked |
|<-----------------------------|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+
| | | FundingTx2 |
| | +------------+
| |
| update_add_htlc | Alice and Bob can use the channel and forget the previous FundingTx1.
|----------------------------->|
| commit_sig |
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| commit_sig |
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 12
| | +------------+
| | | FundingTx2 |
| | +------------+
Since nodes have different views of the blockchain, they may send splice_locked at slightly different times.
Moreover, nodes may send splice_locked concurrently with other channel updates, in which case they will receive some commit_sig messages for obsolete commitments.
This is fine: nodes know how many commit_sig messages to expect thanks to the batch_size field, and they can simply ignore commit_sig messages for which the funding_txid cannot be found in the active commitments.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| tx_signatures |
|<-----------------------------|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +-------------+
| | | FundingTx1 |------->| FundingTx2a |
| | +------------+ +-------------+
| |
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| tx_init_rbf | Alice RBFs the splice attempt.
|----------------------------->|
| tx_ack_rbf |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| tx_signatures |
|<-----------------------------|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +-------------+
| | | FundingTx1 |---+--->| FundingTx2a |
| | +------------+ | +-------------+
| | |
| | | +-------------+
| | +--->| FundingTx2b |
| | +-------------+
| |
| update_add_htlc | Alice and Bob use the channel while the splice transactions are unconfirmed.
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 3
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2a, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2b, commitment_number = 11
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| start_batch | batch_size = 3
|<-----------------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2a, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2b, commitment_number = 11
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+ +-------------+
| | | FundingTx1 |---+--->| FundingTx2a |
| | +------------+ | +-------------+
| | |
| | | +-------------+
| | +--->| FundingTx2b |
| | +-------------+
| |
| splice_locked | splice_txid = FundingTx2a
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 3
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 12 -> this message will be ignored by Bob since FundingTx2a will be locked before the end of the batch
|----------------------------->|
| splice_locked | splice_txid = FundingTx2a
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2a, commitment_number = 12
|----------------------------->|
| commit_sig | funding_txid = FundingTx2b, commitment_number = 12 -> this message can be ignored by Bob since FundingTx2a has been locked
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| commit_sig |
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 12
| | +-------------+
| | | FundingTx2b |
| | +-------------+
In this scenario, a disconnection happens when one side has sent commit_sig but not the other.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before receiving Bob's tx_complete:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
| X----------------------|
| commit_sig |
| X----------------------|
| | Active commitments for Alice:
| |
| | commitment_number = 10
| | +------------+
| | | FundingTx1 |
| | +------------+
| |
| | Active commitments for Bob:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 10, next_revocation_number = 10
|<-----------------------------|
| tx_abort |
|----------------------------->|
| tx_abort |
|<-----------------------------|
| | Bob can safely forget the splice attempt because he hasn't sent tx_signatures.
| | Active commitments for Alice and Bob:
| |
| | commitment_number = 10
| | +------------+
| | | FundingTx1 |
| | +------------+
In this scenario, a disconnection happens when both sides have sent commit_sig.
They are able to resume the signatures exchange on reconnection.
In this example, Bob is supposed to send tx_signatures first.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before receiving Bob's commit_sig:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|--------------------X |
| commit_sig |
| X----------------------|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 10, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 10, next_revocation_number = 10
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
In this scenario, a disconnection happens when one side has sent tx_signatures but not the other.
They are able to resume the signatures exchange on reconnection.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before receiving Bob's tx_signatures:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
| X----------------------|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 11, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 11, next_revocation_number = 10
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
In this scenario, a disconnection happens when both sides have sent tx_signatures, but one side has not received it.
They are able to resume the signatures exchange on reconnection.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before Bob receives her tx_signatures:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------X |
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 11, next_revocation_number = 10
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
In this scenario, a disconnection happens when both sides have sent tx_signatures, but one side has not received it.
The second signer also sent a new signature for additional changes to apply after their tx_signatures.
They are able to resume the signatures exchange on reconnection and retransmit new updates.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before Bob receives her tx_signatures and new updates:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------X |
| update_add_htlc |
|----------------------X |
| start_batch | batch_size = 2
|----------------------X |
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------X |
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------X |
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = FundingTx2, next_commitment_number = 11, next_revocation_number = 10
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 2
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| start_batch | batch_size = 2
|<-----------------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
In this scenario, disconnections happen while nodes are exchanging splice_locked.
We use the my_current_funding_locked field to "lock" the latest splice on reconnection.
Initial active commitments:
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnections happen when exchanging splice_locked:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| splice_locked |
|---------------------X |
| | Active commitments:
| |
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, my_current_funding_locked = funding_tx2
|----------------------------->|
| channel_reestablish | next_funding_txid = null, my_current_funding_locked = funding_tx1
|<-----------------------------|
| |
| splice_locked | At that point, Bob has locked funding_tx2, but Alice doesn't know it because she hasn't received splice_locked yet.
| X----------------------|
| |
| channel_reestablish | next_funding_txid = null, my_current_funding_locked = funding_tx2
|----------------------------->|
| channel_reestablish | next_funding_txid = null, my_current_funding_locked = funding_tx2
|<-----------------------------|
| | Bob's my_current_funding_locked lets Alice know that Bob has locked funding_tx2 while they were disconnected.
| | She can thus immediately lock it as well even though she hasn't received Bob's splice_locked.
| |
| | Active commitments:
| |
| | +------------+
| | | FundingTx2 |
| | +------------+
| |
| update_add_htlc |
|----------------------------->|
| commit_sig | Alice doesn't need to sent commit_sig for funding_tx1 since funding_tx2 was locked.
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| commit_sig |
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
In this scenario, a disconnection happens when both sides have sent and received tx_signatures.
The second signer also sent a new signature for additional changes to apply after their tx_signatures.
They are able to resume the signature exchange on reconnection and continue with the commit_sig exchange.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before Bob receives her commit_sigs for new updates:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 2
|----------------------X |
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------X |
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------X |
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|<-----------------------------|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 2
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| start_batch | batch_size = 2
|<-----------------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
Disconnection after exchanging tx_signatures and both sides send commit_sig for channel update; revoke_and_ack not received
In this scenario, a disconnection happens when both sides have sent and received tx_signatures.
Both signers also send new signatures for additional changes to apply after their tx_signatures.
The first signer has not received the second signer's revoke_and_ack message for the channel update.
They are able to resume the signature exchange on reconnection.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before Bob receives her revoke_and_ack and commit_sigs for new updates:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 2
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------------->|
| revoke_and_ack |
| X----------------------|
| start_batch | batch_size = 2
| X----------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
| X----------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
| X----------------------|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|----------------------------->|
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|<-----------------------------|
| revoke_and_ack |
|<-----------------------------|
| start_batch | batch_size = 2
|<-----------------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
In this scenario, a disconnection happens when both sides have sent and received tx_signatures.
Both signers also send new signatures for additional changes to apply after their tx_signatures.
The first signer has received the second signer's revoke_and_ack message for the channel update.
They are able to resume the signature exchange on reconnection.
Initial active commitments:
commitment_number = 10
+------------+
| FundingTx1 |
+------------+
Alice initiates a splice, but disconnects before she receives Bob's commit_sigs for new updates:
Alice Bob
| stfu |
|----------------------------->|
| stfu |
|<-----------------------------|
| splice_init |
|----------------------------->|
| splice_ack |
|<-----------------------------|
| |
| <interactive-tx> |
|<---------------------------->|
| |
| tx_complete |
|----------------------------->|
| tx_complete |
|<-----------------------------|
| commit_sig |
|----------------------------->|
| commit_sig |
|<-----------------------------|
| tx_signatures |
|<-----------------------------|
| tx_signatures |
|----------------------------->|
| update_add_htlc |
|----------------------------->|
| start_batch | batch_size = 2
|----------------------------->|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|----------------------------->|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|----------------------------->|
| revoke_and_ack |
|<-----------------------------|
| start_batch | batch_size = 2
| X----------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
| X----------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
| X----------------------|
| | Active commitments:
| |
| | commitment_number = 10
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+
| |
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 11
|----------------------------->|
| channel_reestablish | next_funding_txid = null, next_commitment_number = 11, next_revocation_number = 10
|<-----------------------------|
| start_batch | batch_size = 2
|<-----------------------------|
| commit_sig | funding_txid = FundingTx1, commitment_number = 11
|<-----------------------------|
| commit_sig | funding_txid = FundingTx2, commitment_number = 11
|<-----------------------------|
| revoke_and_ack |
|----------------------------->|
| | Active commitments:
| |
| | commitment_number = 11
| | +------------+ +------------+
| | | FundingTx1 |------->| FundingTx2 |
| | +------------+ +------------+