Reserve metadata slot at SplicePending/ChannelPending#59
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ldk-node lists the splice or channel funding tx as an outbound on-chain payment the moment it broadcasts, but our tx_metadata entry isn't inserted until the rebalancer's OnChainRebalanceInitiated handler runs. A concurrent list_transactions call sees an outbound payment with no metadata and trips a debug_assert. Reserve a PendingRebalance placeholder at SplicePending and ChannelPending, which list_transactions already skips. Combine the trigger promotion and splice upsert in OnChainRebalanceInitiated into a single write-lock acquisition so the trigger and splice metadata are never visible to a reader in a half-updated state. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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ldk-node adds the splice or channel funding tx to its payment store as an outbound on-chain payment the moment it broadcasts, but our
tx_metadataentry is only inserted later, when the graduated rebalancer'sOnChainRebalanceInitiatedhandler runs afterawait_splice_pending/await_channel_pendingreturns. A concurrentlist_transactionscall (e.g. from a test'swait_for_condition, or from the user after observing theSplicePendingevent) hitting the gap sees an outbound payment with no metadata and trips thedebug_assert_ne!inlist_transactions.Reserve a
PendingRebalanceplaceholder insideLdkEventHandler'sSplicePendingandChannelPendingbranches, using the funding txid delivered with each event.SplicePendinginserts the placeholder before signallingsplice_pending_senderand before enqueueing the publicEvent::SplicePending, so any caller waking up on either signal already sees the entry.list_transactionsalready skipsPendingRebalance, and the rebalancer'sOnChainRebalanceInitiatedhandler upserts the slot toOnchainToLightningonce it has the trigger info. User-initiated splice-outs likewise overwrite the placeholder withTxType::Paymentwhenpay_lightningfinishes.