From c6ce35240413812a1dca6bc79f1872a2366b0fcc Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Mon, 29 Jan 2018 12:51:18 +1030
Subject: [PATCH] lightningd: actually unwatch txs when onchaind says we
 should.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 lightningd/peer_control.c | 15 ++++++++++++++-
 lightningd/watch.c        | 18 ++++++++++++++++++
 lightningd/watch.h        |  4 ++++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index 92ef7b23a..e84fb0202 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -1193,7 +1193,20 @@ static void handle_onchain_broadcast_tx(struct peer *peer, const u8 *msg)
 
 static void handle_onchain_unwatch_tx(struct peer *peer, const u8 *msg)
 {
-	/* FIXME: unwatch tx and children here. */
+	struct bitcoin_txid txid;
+	struct txwatch *txw;
+
+	if (!fromwire_onchain_unwatch_tx(msg, NULL, &txid)) {
+		peer_internal_error(peer, "Invalid onchain_unwatch_tx");
+		return;
+	}
+
+	/* Frees the txo watches, too: see watch_tx_and_outputs() */
+	txw = find_txwatch(peer->ld->topology, &txid, peer);
+	if (!txw)
+		log_unusual(peer->log, "Can't unwatch txid %s",
+			    type_to_string(ltmp, struct bitcoin_txid, &txid));
+	tal_free(txw);
 }
 
 static void handle_extracted_preimage(struct peer *peer, const u8 *msg)
diff --git a/lightningd/watch.c b/lightningd/watch.c
index d23499c6e..a843d9cae 100644
--- a/lightningd/watch.c
+++ b/lightningd/watch.c
@@ -112,6 +112,24 @@ struct txwatch *watch_txid_(const tal_t *ctx,
 	return w;
 }
 
+struct txwatch *find_txwatch(struct chain_topology *topo,
+			     const struct bitcoin_txid *txid,
+			     const struct peer *peer)
+{
+	struct txwatch_hash_iter i;
+	struct txwatch *w;
+
+	/* We could have more than one peer watching same txid, though we
+	 * don't for onchaind. */
+	for (w = txwatch_hash_getfirst(&topo->txwatches, txid, &i);
+	     w;
+	     w = txwatch_hash_getnext(&topo->txwatches, txid, &i)) {
+		if (w->peer == peer)
+			break;
+	}
+	return w;
+}
+
 bool watching_txid(const struct chain_topology *topo,
 		   const struct bitcoin_txid *txid)
 {
diff --git a/lightningd/watch.h b/lightningd/watch.h
index e4ba2809a..06f8d76e6 100644
--- a/lightningd/watch.h
+++ b/lightningd/watch.h
@@ -134,6 +134,10 @@ struct txowatch *watch_txo_(const tal_t *ctx,
 				       const struct block *block),	\
 		  (cbdata))
 
+struct txwatch *find_txwatch(struct chain_topology *topo,
+			     const struct bitcoin_txid *txid,
+			     const struct peer *peer);
+
 void txwatch_fire(struct chain_topology *topo,
 		  const struct bitcoin_tx *tx,
 		  unsigned int depth);