commit_tx: keep permutation map.

This lets us map the HTLCs back to outputs when txs occur onchain.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/packets.c

@@ -304,7 +304,8 @@ void queue_pkt_commit(struct peer *peer)
 				  peer->anchor.index,
 				  peer->anchor.satoshis,
 				  &ci->revocation_hash,
-				  ci->cstate);
+				  ci->cstate,
+				  &ci->map);
 
 	log_debug(peer->log, "Signing tx for %u/%u msatoshis, %zu/%zu htlcs",
 		  ci->cstate->a.pay_msat,
@@ -693,7 +694,8 @@ Pkt *accept_pkt_commit(struct peer *peer, const Pkt *pkt)
 				  peer->anchor.index,
 				  peer->anchor.satoshis,
 				  &ci->revocation_hash,
-				  ci->cstate);
+				  ci->cstate,
+				  &ci->map);
 
 	/* BOLT #2:
 	 *

daemon/peer.c

@@ -1330,7 +1330,8 @@ bool setup_first_commit(struct peer *peer)
 					       peer->anchor.index,
 					       peer->anchor.satoshis,
 					       &peer->us.commit->revocation_hash,
-					       peer->us.commit->cstate);
+					       peer->us.commit->cstate,
+					       &peer->us.commit->map);
 
 	peer->them.commit->tx = create_commit_tx(peer->them.commit,
 						 &peer->them.finalkey,
@@ -1340,7 +1341,8 @@ bool setup_first_commit(struct peer *peer)
 						 peer->anchor.index,
 						 peer->anchor.satoshis,
 						 &peer->them.commit->revocation_hash,
-						 peer->them.commit->cstate);
+						 peer->them.commit->cstate,
+						 &peer->them.commit->map);
 
 	peer->us.staging_cstate = copy_funding(peer, peer->us.commit->cstate);
 	peer->them.staging_cstate = copy_funding(peer, peer->them.commit->cstate);

daemon/peer.h

@@ -63,6 +63,8 @@ struct commit_info {
 	struct channel_state *cstate;
 	/* Other side's signature for this commit tx. */
 	struct bitcoin_signature sig;
+	/* Map for permutation: see commit_tx.c */
+	int *map;
 	/* Revocation preimage (if known). */
 	struct sha256 *revocation_preimage;
 };