poll_once and reconcile.py's existence check both called
blockchain.transaction.get(txid, verbose=True). Several Electrum server
implementations and versions reject the verbose flag outright
("verbose transactions are currently unsupported"), which would have
meant no confirmations and no reconciliation ever running against such
a server, read as a plain transport error. reconcile.py additionally
decided whether to abandon a transaction - releasing its funds - by
substring-matching the error text ("missing", "not found", ...), which
only works against ElectrumX's specific wording.
Both now ask blockchain.scripthash.get_history for the address that
owns every input of the transaction (a user's own address for a
bet/withdrawal, the pool address for a payout) and look for the txid in
the result: present with height > 0 means confirmed, present with
height <= 0 means still in the mempool, absent means the server
doesn't know it. get_history is a plain, universally-supported Electrum
method, and "not in the list" replaces the old substring-matching
entirely - no more guessing at error wording to decide whether to
release funds. History is cached per scripthash within one pass, since
every "payout" row shares the same pool address.
New app/tx/pending_address.py factors out own_address_for (the
address derivation was previously duplicated informally inside
tx/broadcast.py's signing context) so confirmation.py and reconcile.py
share one definition instead of two that could compute different
addresses for the same row.
tests/unit/test_confirmation.py and test_reconcile.py needed real User
rows and a master-key bootstrap they didn't have before, since address
derivation is now exercised for real rather than assumed. Suite grows
from 217 to 222 tests. BUGS.md moves B-41 to Previously fixed - no
Medium-severity finding remains open.
The code treated a broadcast as final: money moved on-chain and the DB was
updated on the assumption it would either confirm or be fee-bumped until it
did. Neither is guaranteed, and every way that assumption broke was permanent
(BUGS.md B-02, B-03, B-04, B-07, B-08, B-20, B-21).
Persist before broadcasting. place_bet and request_withdrawal now write their
rows in a "building" state and commit, then broadcast, then promote to
broadcast/pending in a second commit. Before, a failure or crash between the
broadcast and the commit left the coins irreversibly spent with no trace: no
participant (so no entry in the draw), no pending row (so no RBF and no
confirmation tracking), and the UTXOs not even marked spent, so the next bet
would try to double-spend them. A refused broadcast now releases the reserved
UTXOs, restores the balance, removes the participant (or marks the withdrawal
failed), audit-logs it, and answers a translatable broadcast_failed — as 502,
since the network refused it, not the caller, where it used to be an opaque 500.
Reconcile what's in flight against the chain. New PendingTransactionReconciler
(app/tx/reconcile.py, every 120s and once at startup) asks whether each
non-terminal tx exists: present -> promote, gone -> mark failed with a reason,
release the inputs, roll the domain row back, audit-log it. Grace periods differ
by state (120s for "building", 6h for "pending", so the RBF bumper gets its
attempts first). It is deliberately biased to inaction: only a server that
positively doesn't know the tx counts as absent, and a transport failure never
abandons anything, because releasing a UTXO whose tx is actually alive would
invite a double-spend. Verified against the live server, which answers "No such
mempool or blockchain transaction" for an unknown txid.
Stop keying on a value that changes. An RBF bump changes the txid, and
_on_bet_confirmed looked the participant up by bet_txid — so a bumped bet
confirmed under a txid no participant carried, the row stayed "broadcast"
forever, and the scheduler waited on it forever: the round could never close and
the lottery stopped. Handlers now resolve by immutable ids (round_id/user_id,
withdrawal_id), and bump_fee retargets every stored txid — bet_txid,
Withdrawal.txid, Round.payout_txid and UtxoEvent.spent_txid — plus records the
previous one in replaced_by_txid, which was never written at all.
One bad row no longer blocks the rest. The confirmation poller's per-tx lookup
is guarded: a txid the server can't resolve used to abort the whole pass, so
nothing confirmed again until an operator intervened. It also selects plain
columns instead of hydrating entities that outlive their session.
Tests: 6 reconciler cases including "a broken connection must not release coins";
the bet-ordering test probes committed state from an independent session during
the broadcast, and caught a real mistake in the first draft of this change (the
_pending_transaction helper still hardcoded status="pending", so rows were born
already-broadcast and would have got the 6-hour grace instead of 120s).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Shared per-user locking to serialize bet/withdrawal PSBT builds
(tx/locks.py), a confirmation poller for pending outgoing transactions,
and the timeout->fee-bump->rebroadcast loop used by bets, payouts and
withdrawals alike (tx/broadcast.py).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
davide
