Initiated channels do not show total fees for closing txs in getTransactions

[dannypaz]

Background

Channels that I create (initiate) show opening tx fees, but do not show closing tx fees in either getTransactions or lncli listchaintxns

Your environment

• v0.5.1-beta
• Darwin (Mac OS Majave)
• bitcoind 0.17

Steps to reproduce

When a user requests to open a channel with another node, a call to getTransactions returns the opening transaction with the correct total_fees for the opening transaction. Once you close the channel, the transaction shows up under getTransactions however total_fees remains 0 (possibly due to the way we would calculate the fee based on the multisig from the channel)

NOTE This sample data is on regtest but was also performed on mainnet, please reach out directly if you'd like tx information/logs for mainnet

{ amount: '-0.16786002',
  transaction: '8254ecc786633551d2ca5ae32f75629fd6d7940e9c284229b33edd264997910b',
  blockNumber: 6097,
  timestamp: '1555022291',
  fees: '0.00008787' },
{ amount: '0.16768165',
  transaction: '4cbef435eba3370451c53738e3acb35c4bf575877ad05286150649814d548a4c',
  blockNumber: 6127,
  timestamp: '1555022591',
  fees: '0' } ]

Expected behaviour

total_fees contains the amount of fees for the channel close transaction in getTransactions

Actual behaviour

total_fees is 0 in the closing transaction of the channel from the intiator

[vctt94]

can I help with this one?

[vctt94]

I found out what the problem is.

Here on btcwallet https://github.com/btcsuite/btcwallet/blob/master/wallet/notifications.go#L110 the details.Debits is an empty array, therefore, not calculating the fee.

I could think on 2 fixes for that. Calculate it properly on btcwallet, what makes most sense for me.
Or we can calculate the fee at lnd's wallet at https://github.com/lightningnetwork/lnd/blob/master/lnwallet/btcwallet/btcwallet.go#L576

What do you guys suggest?

[halseth]

@vctt94 Sounds like fixing it in btcwallet is the most correct fix. What do you think? :)

[dannypaz]

@vctt94 thanks a ton for grabbing this.

@halseth et.al I wanted to make sure that this was actually a bug. Technically, the transaction that comes back from LND in getTransactions is correct, because the funds are taken out of the inputs from the commitment transactions (multi-sig). At that point, your wallet is just receiving a balance cause the multi-sig paid the fees. Do you think this change would be confusing to users?

[dannypaz]

IMO there needs to be a way that a user can see what fees were paid from channel opening, for accounting purposes, however I had a change of heart RE what getTransactions should be returning

[alexbosworth]

Related issue: #2594