lightningd: handle duplicate watches on the same thing correctly.

lightningd/chaintopology.c

@@ -55,20 +55,22 @@ static void filter_block_txs(struct chain_topology *topo, struct block *b)
 	/* Now we see if any of those txs are interesting. */
 	const size_t num_txs = tal_count(b->full_txs);
 	for (i = 0; i < num_txs; i++) {
-		const struct bitcoin_tx *tx = b->full_txs[i];
+		struct bitcoin_tx *tx = b->full_txs[i];
 		struct bitcoin_txid txid;
 		size_t j;
 		bool is_coinbase = i == 0;
 
 		/* Tell them if it spends a txo we care about. */
 		for (j = 0; j < tx->wtx->num_inputs; j++) {
 			struct bitcoin_outpoint out;
-			struct txowatch *txo;
+			struct txowatch_hash_iter it;
+
 			bitcoin_tx_input_get_txid(tx, j, &out.txid);
 			out.n = tx->wtx->inputs[j].index;
 
-			txo = txowatch_hash_get(topo->txowatches, &out);
-			if (txo) {
+			for (struct txowatch *txo = txowatch_hash_getfirst(topo->txowatches, &out, &it);
+			     txo;
+			     txo = txowatch_hash_getnext(topo->txowatches, &out, &it)) {
 				wallet_transaction_add(topo->ld->wallet,
 						       tx->wtx, b->height, i);
 				txowatch_fire(txo, tx, j, b);
@@ -104,7 +106,7 @@ static void filter_block_txs(struct chain_topology *topo, struct block *b)
 					       tx->wtx, b->height, i);
 		}
 
-		txwatch_inform(topo, &txid, tx);
+		txwatch_inform(topo, &txid, take(tx));
 	}
 	b->full_txs = tal_free(b->full_txs);
 	b->txids = tal_free(b->txids);

lightningd/watch.c

@@ -30,6 +30,7 @@
  * WE ASSUME NO MALLEABILITY!  This requires segregated witness.
  */
 #include "config.h"
+#include <bitcoin/psbt.h>
 #include <lightningd/chaintopology.h>
 #include <lightningd/channel.h>
 #include <lightningd/lightningd.h>
@@ -235,12 +236,13 @@ void txwatch_fire(struct chain_topology *topo,
 		  const struct bitcoin_txid *txid,
 		  unsigned int depth)
 {
-	struct txwatch *txw;
+	struct txwatch_hash_iter it;
 
-	txw = txwatch_hash_get(topo->txwatches, txid);
-
-	if (txw)
+	for (struct txwatch *txw = txwatch_hash_getfirst(topo->txwatches, txid, &it);
+	     txw;
+	     txw = txwatch_hash_getnext(topo->txwatches, txid, &it)) {
 		txw_fire(txw, txid, depth);
+	}
 }
 
 void txowatch_fire(const struct txowatch *txow,
@@ -295,12 +297,22 @@ void watch_topology_changed(struct chain_topology *topo)
 
 void txwatch_inform(const struct chain_topology *topo,
 		    const struct bitcoin_txid *txid,
-		    const struct bitcoin_tx *tx_may_steal)
+		    struct bitcoin_tx *tx TAKES)
 {
-	struct txwatch *txw;
-
-	txw = txwatch_hash_get(topo->txwatches, txid);
+	struct txwatch_hash_iter it;
+
+	for (struct txwatch *txw = txwatch_hash_getfirst(topo->txwatches, txid, &it);
+	     txw;
+	     txw = txwatch_hash_getnext(topo->txwatches, txid, &it)) {
+		if (txw->tx)
+			continue;
+		/* FIXME: YUCK!  These don't have PSBTs attached */
+		if (!tx->psbt)
+			tx->psbt = new_psbt(tx, tx->wtx);
+		txw->tx = clone_bitcoin_tx(txw, tx);
+	}
 
-	if (txw && !txw->tx)
-		txw->tx = tal_steal(txw, tx_may_steal);
+	/* If we don't clone above, handle take() now */
+	if (taken(tx))
+		tal_free(tx);
 }

lightningd/watch.h

@@ -89,10 +89,9 @@ void txowatch_fire(const struct txowatch *txow,
 bool watching_txid(const struct chain_topology *topo,
 		   const struct bitcoin_txid *txid);
 
-/* FIXME: Implement bitcoin_tx_dup() so we tx arg can be TAKEN */
 void txwatch_inform(const struct chain_topology *topo,
 		    const struct bitcoin_txid *txid,
-		    const struct bitcoin_tx *tx_may_steal);
+		    struct bitcoin_tx *tx TAKES);
 
 void watch_topology_changed(struct chain_topology *topo);
 #endif /* LIGHTNING_LIGHTNINGD_WATCH_H */