d52fa1b0a5 tests: Make sure that bumpfee feerate checks work when replacing outputs (Andrew Chow)
be177c15a4 bumpfee: Check the correct feerate when replacing outputs (Andrew Chow)
Pull request description:
When replacing the outputs of a transaction during `bumpfee`, it is possible to accidentally create a transaction that will not be accepted into the mempool as it does not meet the incremental relay fee requirements. This occurs because the size estimation used for checking the provided feerate does not account for the replaced outputs; it instead uses the original outputs. When the replaced outputs is significantly different from the original, there can be a large difference in estimated transaction sizes that can make a transaction miss the absolute fee requirements for the incremental relay fee. Unfortunately we do not currently inform the user when the bumped transaction fails to relay, so they could use `bumpfee` and think the transaction has been bumped when it actually has not.
This issue is resolved by replacing the outputs before doing the size estimation, and also updating the feerate checker to use the actual fee values when calculating the required minimum fee.
Also added a test for this scenario.
ACKs for top commit:
ishaanam:
reACK d52fa1b0a5
Xekyo:
reACK d52fa1b0a5
Tree-SHA512: d18301b587465322dd3fb1bb86496c3675265a56072047576e2baa5cf907dd3b54778f30721f662f0c235709a5568427c18542eb7efbfb6fdd9f481fe676c66b
90bfa9d2d7