Handle `transaction_unconfirmed` as a full reorg to the tx height

In `ChannelMonitor`, if we see a `transaction_unconfirmed` for a
transaction we last saw in a block at height X, we shouldn't
*only* remove the `onchain_events_awaiting_threshold_conf` entry
for the given tx but rather for all transactions that we last saw
at height >= X.

This avoids any potential `onchain_events_awaiting_threshold_conf`
inconsistencies due to the order in whcih users mark transactions
unconfirmed (which the `chain::Confirm` docs do not currently set
any requirements on).

This also matches the `OnchainTxHandler` behavior, which does the
same lookup.

diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index 0bfd944456ab6851749505350c781e8ec267d27e..1933a3f524e8a19c1a2397e37ba053db355e62e0 100644 (file)
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -3111,10 +3111,24 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                F::Target: FeeEstimator,
                L::Target: Logger,
        {
-               self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.txid == *txid {
-                       log_info!(logger, "Removing onchain event with txid {}", txid);
-                       false
-               } else { true });
+               let mut removed_height = None;
+               for entry in self.onchain_events_awaiting_threshold_conf.iter() {
+                       if entry.txid == *txid {
+                               removed_height = Some(entry.height);
+                               break;
+                       }
+               }
+
+               if let Some(removed_height) = removed_height {
+                       log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
+                       self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
+                               log_info!(logger, "Transaction {} reorg'd out", entry.txid);
+                               false
+                       } else { true });
+               }
+
+               debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
+
                self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
        }