In CreatePeginWitnessInner, the MerkleBlock is always serialized without
witness: PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS
In DecomposePeginWitness before this change, the MerkleBlock was
deserialized with witness: PROTOCOL_VERSION
This was only noticed as an issue in the pegin subsidy implementation,
in a failure in the feature_dynafed functional test. In the
test_transition_mempool_eject test case, the Merkle block proof is coming
from the same chain where we are creating a pegin.
See the comment: "hack: since we're not validating peg-ins in parent chain,
just make both the funding and claim tx on same chain (printing money)"
I haven't investigated enough to explain why this causes a
deserialization failure in this specific case, but presumably this change
is correct since we're always serializing without witness. Before this
DecomposePeginWitness was only used in src/psbt.cpp
Currently, if -validatepegin is given, and block validation can't proceed
because the parent chain is not synced, we mark the block invalid and put
it in a queue to be "revalidated" later. Unfortunately, marking a block
invalid has downstream consequences, in particular causing descendant blocks
to be marked invalid, which are not currently fixed by the queue.
Instead, we'll use a different strategy: if the mainchain daemon isn't
sufficiently synced to validate a block, we will "stall" connecting that
block to the chain, and have ActivateBestChain simply keep the tip at the
previous block until we're ready.
We can still download and validate (partly) blocks past this point while
we're waiting. They will be connected once the parent chain daemon catches
up.
Surprisingly easy to do. Almost all of the diff resolution was mechanically
* replacing boost::variant with std::variant
* replacing Optional with std::optional
* then replacing `nullopt` with `std::nullopt`
* updating the RPC functions for the new RPCArg::Default type
* update the tests/ directory to make new (since 22) tests use arrays for
createrawtransaction outputs
* other ad-hoc changes to function parameters etc (not too many of these)
I had to "really" change the code in PrecomputePSBTData, which was introduced
in 22.0 and affected by PSET, but this function was like 8 lines long so it
was easy.
Reviewing the diff may be a bit difficult because of the mix of mechanical
changes and ad-hoc things. Probably the most straightforward thing to do
is to redo the merge, `sed -i` to fix the boost::variant and Optional stuff,
then diff the remaining conflicts against this commit.
TODO: grep for `blindpsbt` and you will see that this RPC is still referenced
in documentation and help text even though it was deleted. Need to fix this
in 0.21 in a separate PR.
I really like this PR, but it wound up being pretty nontrivial to merge.
The crux is that it pulls PSBT signing logic into scriptpubkey manager,
which is where it belongs, but for us this means reasoning about pegins
inside script/sign.cpp.
However, sign.cpp is part of libbitcoin_common, which does not include
anything for reasoning about PoW or RPC (lol) or anything heavy about
that. This means that some pegin validation had to remain split between
the wallet/rpc layer and sign.cpp. I added a new file script/pegins.cpp
which has the (one) method we actually need in sign.cpp.
Aside from that, this diff is very large but is mostly just moving our
code changes to wallet/psbtwallet.* into wallet/wallet.* where those
functions now live. As far as review, it's probably not worthwhile to
spend too much too much time on this since it's going to be change
again in #16528 and others. The test coverage is pretty extensive.
