This was a difficult merge as always with diffs that touch spend.cpp and
createtransactioninternal. Added a FIXME NB for fundrawtransaction with
external outputs, which MUST be fixed before a new release.
This should be reviewed carefully. The new availablecoins_test was
showing an intermittent error [1]. The test variants were split out into
their own test cases to work around the issue, but requires further
investigation.
[1]: https://github.com/ElementsProject/elements/issues/1370
Please reviewthis commit *extremely thoroughly*.
This commit changed how certain transaction size calculations are done.
This altered fee estiimation for certain elements transactions, and caused a lot
of things to break in the `wallet_bumpfee` functional test.
After *extensive* work (~10 hours), I managed to figure all this out and properly
reconcile the functional test to work with the new fee calculations.
However, the original bitcoin commit didn't have any changes to this functional test.
So, it's also simply possible that I may have made an actual bug and these fee issues
I was seeing in the functional test were pointing at this bug.
I'm not sure if there is a bug. I don't think so... I think the transaction estimations just got
bigger in certain cases.
But... please verify this. Look into the diff of this commit, and compare how use_max_sig used
to be calculated in a bunch of different ways for different use cases, but is now being calculated
only once (inside of DummySignInput), in the same way for all use cases. Did I accidentally introduce
a bug there?
In other words... I'm not certain about the wallet changes here. Please double and triple check them.
Thanks!
576bee88fd fuzz: disable BnB when SFFO is enabled (furszy)
05e5ff194c test: add coverage for BnB-SFFO restriction (furszy)
0c5755761c wallet: create tx, log resulting coin selection info (furszy)
5cea25ba79 wallet: skip BnB when SFFO is active (Murch)
Pull request description:
Solves #28918. Coming from https://github.com/bitcoin/bitcoin/issues/28918#issuecomment-1838626406 discussion.
The intention is to decouple only the bugfix relevant commits from #28985, allowing them to be included in the 26.x release. This way, we can avoid disabling the coin selection fuzzing test for an entire release.
Note:
Have introduced few changes to the bug fix commit so that the unit tests pass without the additional burden introduced in #28985.
ACKs for top commit:
josibake:
ACK 576bee88fd
murchandamus:
ACK 576bee88fd
achow101:
ACK 576bee88fd
Tree-SHA512: f5d90eb3f3f524265afe4719495c9bf30f98b9af26cf039f7df5a7db977abae72caa7a3478cdd0ab10cd143bc1662e8fc5286b5bc10fc10f0dd582a45b45c31a
Verify the transaction creation process does not produce
a BnB solution when SFFO is enabled.
This is currently problematic because it could require a
change output. And BnB is specialized on changeless solutions.
Co-authored-by: Andrew Chow <achow101@gmail.com>
Co-authored-by: Murch <murch@murch.one>
Instead of having a separate CCoinControl::SelectExternal function, we
can use the normal CCoinControl::Select function and explicitly use
PreselectedInput::SetTxOut in the caller. The semantics of what an
external input is remains.
When a transaction uses an unconfirmed input, preceding this commit it
would not consider the feerate of the parent transaction. Given a parent
transaction with a lower ancestor feerate, this resulted in the new
transaction's ancestor feerate undershooting the target feerate.
This commit changes how we calculate the effective value of unconfirmed UTXOs.
The effective value of unconfirmed UTXOs is decreased by the fee
necessary to bump its ancestry to the target feerate. This also impacts
the calculation of the waste metric: since the estimate for the current
fee is increased by the bump fees, unconfirmed UTXOs current fees appear less
favorable compared to their unchanged long term fees.
This has one caveat: if multiple UTXOs have overlapping ancestries, each
of their individual estimates will account for bumping all ancestors.
GetSelectionWaste will need to access more context within a selection
result, and so should be a private member function rather than a static
function. It's only use outside of SelectionResult was for tests which
have now been updated to just make a SelectionResult.
Co-authored-by: Murch <murch@murch.one>
1771daa815 [fuzz] Show that SRD budgets for non-dust change (Murch)
941b8c6539 [bug] Increase SRD target by change_fee (Murch)
Pull request description:
I discovered via fuzzing of another coin selection approach that at extremely high feerates SRD may find input sets that lead to transactions without change outputs. This is an unintended outcome since SRD is meant to always produce a transaction with a change output—we use other algorithms to specifically search for changeless solutions.
The issue occurs when the flat allowance of 50,000 ṩ for change is insufficient to pay for the creation of a change output with a non-dust amount, at and above 1,613 ṩ/vB. Increasing the change budget by `change_fee` makes SRD behave as expected at any feerates.
Note: The intermittent failures of `test/functional/interface_usdt_mempool.py` are a known issue: https://github.com/bitcoin/bitcoin/issues/27380
ACKs for top commit:
achow101:
ACK 1771daa815
S3RK:
ACK 1771daa815
Tree-SHA512: 3f36a3e317ef0a711d0e409069c05032bff1d45403023f3728bf73dfd55ddd9e0dc2a9969d4d69fe0a426807ebb0bed1f54abfc05581409bfe42c327acf766d4
I discovered via fuzzing of another coin selection approach that at
extremely high feerates SRD may find input sets that lead to
transactions without change outputs. This is an unintended outcome since
SRD is meant to always produce a transaction with a change output—we use
other algorithms to specifically search for changeless solutions.
The issue occures when the flat allowance of 50,000 ṩ for change is
insufficient to pay for the creation of a change output with a non-dust
amount, at and above 1,613 ṩ/vB. Increasing the change budget by
change_fees makes SRD behave as expected at any feerates.
