Addresses #17043, affects RBF and BIP68 functional tests.
The "tx-size-small" policy rule rejects transactions with a non-witness size of
smaller than 82 bytes (see src/validation.cpp:MemPoolAccept::PreChecks(...)),
which corresponds to a transaction with 1 segwit input and 1 P2WPKH output.
Through the default address change, the created test transactions have segwit
inputs now and sending to short scriptPubKeys might violate this rule. By
bumping the dummy scriptPubKey size to 22 bytes (= the size of a P2WPKH
scriptPubKey), on all occurences the problem is solved.
The dummy scriptPubKey has the format:
21 <21-byte-long string of 'a' or 1s>
former commit messages, now squashed:
test: rbf, bip68: use constant DUMMY_P2WPKH_SCRIPT for bumped scriptPubKey
test: rbf, bip68: use constant DUMMY_P2WPKH_SCRIPT for dummy scriptPubKeys (b'a' * 35)
test: rbf, bip68: comment DUMMY_P2WPKH_SCRIPT constant, put into common (new) module
At this point there is no reasonable excuse to disable opt-in RBF,
and, unlike when this option was added, there are now significant
issues created when disabling it (in the form of compact block
reconstruction failures). Further, it breaks a lot of modern wallet
behavior.
870bd4c73d Update functional RBF test to check replaceable flag (dexX7)
820d31f95f Add "bip125-replaceable" flag to mempool RPCs (dexX7)
Pull request description:
This pull request adds a flag "bip125-replaceable" to the mempool RPCs getrawmempool, getmempoolentry, getmempoolancestors and getmempooldescendants, which indicates whether an unconfirmed transaction might be replaced.
Initially the flag was added to the raw transaction RPCs, but thanks to @conscott, it was moved to the mempool RPCs, which actually have access to the mempool.
~~This pull request adds a flag "bip125-replaceable" to the RPCs "getrawtransaction" and "decoderawtransaction", which indicates, whether a transaction signals BIP 125 replaceability.~~
There was some discussion in #7817, whether showing replaceability in the UI could lead to the false assumption that transactions that don't signal BIP 125 are truely non-replaceable, but given that this PR tackles the raw transaction interface, which is a rather low level tool, I believe having this extra piece of information isn't bad.
Tree-SHA512: 1f5511957af2c20a9a6c79d80a335c3be37a2402dbf829c40cceaa01a24868eab81a9c1cdb0b3d77198fa3bb82799e3540a5c0ce7f35bbac80d73f7133ff7cbc