gather_updates: extract some update logic into update_rhash.

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

test-cli/gather_updates.c

@@ -23,13 +23,25 @@ static void check_preimage(const Sha256Hash *preimage,
 		errx(1, "Invalid preimage in %s!", file);
 }
 
-static void get_rhash(const Sha256Hash *rhash, struct sha256 *old,
-		      struct sha256 *new)
+static void update_rhash(const Sha256Hash *rhash,
+			 bool received,
+			 size_t *num_updates,
+			 struct sha256 *old_our_rhash,
+			 struct sha256 *old_their_rhash,
+			 struct sha256 *our_rhash,
+			 struct sha256 *their_rhash)
 {
-	if (new) {
-		*old = *new;
-		proto_to_sha256(rhash, new);
+	/* Update rhash (and save old one for checking) */
+	if (received) {
+		*old_their_rhash = *their_rhash;
+		proto_to_sha256(rhash, their_rhash);
+	} else {
+		*old_our_rhash = *our_rhash;
+		proto_to_sha256(rhash, our_rhash);
 	}
+	/* If they care, we count number of updates. */
+	if (num_updates)
+		(*num_updates)++;
 }
 
 /* Takes complete update history, gets summary of last state. */
@@ -43,7 +55,7 @@ struct channel_state *gather_updates(const tal_t *ctx,
 			struct signature *their_commit_sig)
 {
 	Signature *sig = NULL;
-	struct sha256 old_our_rhash, old_their_rhash;
+	struct sha256 old_our_rhash, old_their_rhash, rhash1, rhash2;
 	struct channel_state *cstate;
 	
 	/* Start sanity check. */
@@ -51,11 +63,15 @@ struct channel_state *gather_updates(const tal_t *ctx,
 	if (!cstate)
 		errx(1, "Invalid open combination (need 1 anchor offer)");
 
-	if (our_rhash)
-		proto_to_sha256(o1->revocation_hash, our_rhash);
+	/* If they don't want these, use dummy ones. */
+	if (!our_rhash)
+		our_rhash = &rhash1;
+
+	if (!their_rhash)
+		their_rhash = &rhash2;
 
-	if (their_rhash)
-		proto_to_sha256(o2->revocation_hash, their_rhash);
+	proto_to_sha256(o1->revocation_hash, our_rhash);
+	proto_to_sha256(o2->revocation_hash, their_rhash);
 
 	/* If o2 sent anchor, it contains their commit sig. */
 	if (o2->anch == OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR)
@@ -82,33 +98,30 @@ struct channel_state *gather_updates(const tal_t *ctx,
 			if (received)
 				sig = pkt->open_commit_sig->sig;
 			break;
-		case PKT__PKT_UPDATE: {
-			if (received) {
+		case PKT__PKT_UPDATE:
+			if (received)
 				delta = -pkt->update->delta;
-				get_rhash(pkt->update->revocation_hash,
-					  &old_their_rhash, their_rhash);
-			} else {
+			else
 				delta = pkt->update->delta;
-				get_rhash(pkt->update->revocation_hash,
-					  &old_our_rhash, our_rhash);
-			}
 			if (!funding_delta(o1, o2, oa, delta, 0,
 					   &cstate->a, &cstate->b))
 				errx(1, "Impossible funding update %lli %s",
 				     (long long)delta, *argv);
-			if (num_updates)
-				(*num_updates)++;
+
+			update_rhash(pkt->update->revocation_hash,
+				     received, num_updates,
+				     &old_our_rhash, &old_their_rhash,
+				     our_rhash, their_rhash);
 			break;
-		}
 		case PKT__PKT_UPDATE_ACCEPT:
-			if (received) {
+			if (received)
 				sig = pkt->update_accept->sig;
-				get_rhash(pkt->update_accept->revocation_hash,
-					  &old_their_rhash, their_rhash);
-			} else {
-				get_rhash(pkt->update_accept->revocation_hash,
-					  &old_our_rhash, our_rhash);
-			}
+
+			/* Does not increase num_updates */
+			update_rhash(pkt->update_accept->revocation_hash,
+				     received, NULL,
+				     &old_our_rhash, &old_their_rhash,
+				     our_rhash, their_rhash);
 			break;
 		case PKT__PKT_UPDATE_SIGNATURE:
 			if (received) {