lightningd: make wallet_extract_owned_outputs return bool, optionally output numbers.

diff --git a/lightningd/chaintopology.c b/lightningd/chaintopology.c
index 0b2caec7..1f460e84 100644
--- a/lightningd/chaintopology.c
+++ b/lightningd/chaintopology.c
@@ -71,7 +71,7 @@ static void filter_block_txs(struct chain_topology *topo, struct block *b)
 		txid = b->txids[i];
 		if (txfilter_match(filter, tx)) {
 			wallet_extract_owned_outputs(topo->bitcoind->ld->wallet,
-						     tx->wtx, is_coinbase, &b->height);
+						     tx->wtx, is_coinbase, &b->height, NULL);
 			wallet_transaction_add(topo->ld->wallet, tx->wtx,
 					       b->height, i);
 			// invoice_check_onchain_payment(tx);
diff --git a/lightningd/channel_control.c b/lightningd/channel_control.c
index f03d224c..4a7a9b09 100644
--- a/lightningd/channel_control.c
+++ b/lightningd/channel_control.c
@@ -523,18 +523,17 @@ static void handle_tx_broadcast(struct send_splice_info *info)
 	struct json_stream *response;
 	struct bitcoin_txid txid;
 	u8 *tx_bytes;
-	int num_utxos;
 	struct splice_command *cc;
 
 	tx_bytes = linearize_tx(tmpctx, info->final_tx);
 	bitcoin_txid(info->final_tx, &txid);
 
 	/* This might have spent UTXOs from our wallet */
-	num_utxos = wallet_extract_owned_outputs(ld->wallet,
-						 info->final_tx->wtx, false,
-						 NULL);
-	if (num_utxos)
+	if (wallet_extract_owned_outputs(ld->wallet,
+					 info->final_tx->wtx, false,
+					 NULL, NULL)) {
 		wallet_transaction_add(ld->wallet, info->final_tx->wtx, 0, 0);
+	}
 
 	cc = splice_command_for_chan(ld, info->channel);
 
diff --git a/lightningd/dual_open_control.c b/lightningd/dual_open_control.c
index a605a528..cbd43ca5 100644
--- a/lightningd/dual_open_control.c
+++ b/lightningd/dual_open_control.c
@@ -1655,14 +1655,13 @@ static void handle_tx_broadcast(struct channel_send *cs)
 	struct command *cmd = channel->openchannel_signed_cmd;
 	struct json_stream *response;
 	struct bitcoin_txid txid;
-	int num_utxos;
 
 	/* This might have spent UTXOs from our wallet */
-	num_utxos = wallet_extract_owned_outputs(ld->wallet,
-						 /* FIXME: what txindex? */
-						 wtx, false, NULL);
-	if (num_utxos)
+	if (wallet_extract_owned_outputs(ld->wallet,
+					 /* FIXME: what txindex? */
+					 wtx, false, NULL, NULL)) {
 		wallet_transaction_add(ld->wallet, wtx, 0, 0);
+	}
 
 	if (cmd) {
 		response = json_stream_success(cmd);
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index d6393ffa..94fb9b85 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -310,7 +310,7 @@ static struct bitcoin_tx *sign_and_send_last(const tal_t *ctx,
 	tx = sign_last_tx(ctx, channel, last_tx, last_sig);
 	bitcoin_txid(tx, &txid);
 	wallet_transaction_add(ld->wallet, tx->wtx, 0, 0);
-	wallet_extract_owned_outputs(ld->wallet, tx->wtx, false, NULL);
+	wallet_extract_owned_outputs(ld->wallet, tx->wtx, false, NULL, NULL);
 
 	/* Remember anchor information for commit_tx_boost */
 	adet = create_anchor_details(NULL, channel, tx);
diff --git a/lightningd/test/run-invoice-select-inchan.c b/lightningd/test/run-invoice-select-inchan.c
index 4dd160f3..bb27f087 100644
--- a/lightningd/test/run-invoice-select-inchan.c
+++ b/lightningd/test/run-invoice-select-inchan.c
@@ -675,9 +675,11 @@ void wallet_channel_save(struct wallet *w UNNEEDED, struct channel *chan UNNEEDE
 void wallet_delete_peer_if_unused(struct wallet *w UNNEEDED, u64 peer_dbid UNNEEDED)
 { fprintf(stderr, "wallet_delete_peer_if_unused called!\n"); abort(); }
 /* Generated stub for wallet_extract_owned_outputs */
-int wallet_extract_owned_outputs(struct wallet *w UNNEEDED, const struct wally_tx *tx UNNEEDED,
-				 bool is_coinbase UNNEEDED,
-				 const u32 *blockheight UNNEEDED)
+bool wallet_extract_owned_outputs(struct wallet *w UNNEEDED,
+				  const struct wally_tx *wtx UNNEEDED,
+				  bool is_coinbase UNNEEDED,
+				  const u32 *blockheight UNNEEDED,
+				  size_t **outputs UNNEEDED)
 { fprintf(stderr, "wallet_extract_owned_outputs called!\n"); abort(); }
 /* Generated stub for wallet_htlcs_load_in_for_channel */
 bool wallet_htlcs_load_in_for_channel(struct wallet *wallet UNNEEDED,
diff --git a/wallet/wallet.c b/wallet/wallet.c
index a8f4da06..fdfa48ed 100644
--- a/wallet/wallet.c
+++ b/wallet/wallet.c
@@ -3365,11 +3365,13 @@ type_ok:
 		*outpoint = utxo->outpoint;
 }
 
-int wallet_extract_owned_outputs(struct wallet *w, const struct wally_tx *wtx,
-				 bool is_coinbase,
-				 const u32 *blockheight)
+bool wallet_extract_owned_outputs(struct wallet *w,
+				  const struct wally_tx *wtx,
+				  bool is_coinbase,
+				  const u32 *blockheight,
+				  size_t **outputs)
 {
-	int num_utxos = 0;
+	bool matched = false;
 
 	for (size_t i = 0; i < wtx->num_outputs; i++) {
 		const struct wally_tx_output *txout = &wtx->outputs[i];
@@ -3384,9 +3386,11 @@ int wallet_extract_owned_outputs(struct wallet *w, const struct wally_tx *wtx,
 			continue;
 
 		got_utxo(w, keyindex, addrtype, wtx, i, is_coinbase, blockheight, NULL);
-		num_utxos++;
+		matched = true;
+		if (outputs)
+			tal_arr_expand(outputs, i);
 	}
-	return num_utxos;
+	return matched;
 }
 
 void wallet_htlc_save_in(struct wallet *wallet,
diff --git a/wallet/wallet.h b/wallet/wallet.h
index dcfc3878..d7a13132 100644
--- a/wallet/wallet.h
+++ b/wallet/wallet.h
@@ -801,10 +801,18 @@ u32 wallet_blocks_contig_minheight(struct wallet *w);
 
 /**
  * wallet_extract_owned_outputs - given a tx, extract all of our outputs
+ * @w: wallet
+ * @is_coinbase: true if this is output 0 (can't spend for 100 blocks)
+ * @blockheight: non-NULL blockheight if known.
+ * @outputs: if non-NULL, output numbers of owned outputs are appended to it.
+ *
+ * Returns true if at least one output was to one of our addresses.
  */
-int wallet_extract_owned_outputs(struct wallet *w, const struct wally_tx *tx,
-				 bool is_coinbase,
-				 const u32 *blockheight);
+bool wallet_extract_owned_outputs(struct wallet *w,
+				  const struct wally_tx *wtx,
+				  bool is_coinbase,
+				  const u32 *blockheight,
+				  size_t **outputs);
 
 /**
  * wallet_htlc_save_in - store an htlc_in in the database
diff --git a/wallet/walletrpc.c b/wallet/walletrpc.c
index 4ea6b3b0..3c022f96 100644
--- a/wallet/walletrpc.c
+++ b/wallet/walletrpc.c
@@ -1027,7 +1027,7 @@ static void sendpsbt_done(struct bitcoind *bitcoind UNUSED,
 	wally_txid(sending->wtx, &txid);
 
 	/* Extract the change output and add it to the DB */
-	if (wallet_extract_owned_outputs(ld->wallet, sending->wtx, false, NULL) == 0) {
+	if (!wallet_extract_owned_outputs(ld->wallet, sending->wtx, false, NULL, NULL)) {
 		/* If we're not watching it for selfish reasons (i.e. pure send to
 		 * others), make sure we're watching it so we can update depth in db */
 		watch_unconfirmed_txid(ld, ld->topology, &txid);