pay: Make wallet_payment->destination optional

If we use `sendonion` we don't actually know the destination, so we
make the destination a pointer which is NULL if we don't know.

lightningd/pay.c

@@ -80,7 +80,9 @@ void json_add_payment_fields(struct json_stream *response,
 {
 	json_add_u64(response, "id", t->id);
 	json_add_sha256(response, "payment_hash", &t->payment_hash);
-	json_add_node_id(response, "destination", &t->destination);
+	if (t->destination != NULL)
+		json_add_node_id(response, "destination", t->destination);
+
 	json_add_amount_msat_compat(response, t->msatoshi,
 				    "msatoshi", "amount_msat");
 	json_add_amount_msat_compat(response, t->msatoshi_sent,
@@ -738,12 +740,14 @@ send_payment(struct lightningd *ld,
 								   struct amount_msat,
 								   &payment->msatoshi));
 			}
-			if (!node_id_eq(&payment->destination, &ids[n_hops-1])) {
+			if (payment->destination &&
+			    !node_id_eq(payment->destination,
+					&ids[n_hops - 1])) {
 				return command_fail(cmd, PAY_RHASH_ALREADY_USED,
 						    "Already succeeded to %s",
 						    type_to_string(tmpctx,
 								   struct node_id,
-								   &payment->destination));
+								   payment->destination));
 			}
 			return sendpay_success(cmd, payment);
 		}
@@ -800,7 +804,7 @@ send_payment(struct lightningd *ld,
 	payment = tal(hout, struct wallet_payment);
 	payment->id = 0;
 	payment->payment_hash = *rhash;
-	payment->destination = ids[n_hops - 1];
+	payment->destination = tal_dup(payment, struct node_id, &ids[n_hops - 1]);
 	payment->status = PAYMENT_PENDING;
 	payment->msatoshi = msat;
 	payment->msatoshi_sent = route[0].amount;

wallet/test/run-wallet.c

@@ -1248,7 +1248,8 @@ static bool test_payment_crud(struct lightningd *ld, const tal_t *ctx)
 	struct wallet *w = create_test_wallet(ld, ctx);
 
 	mempat(t, sizeof(*t));
-	memset(&t->destination, 2, sizeof(t->destination));
+	t->destination = tal(t, struct node_id);
+	memset(t->destination, 2, sizeof(struct node_id));
 
 	t->id = 0;
 	t->msatoshi = AMOUNT_MSAT(100);
@@ -1263,7 +1264,7 @@ static bool test_payment_crud(struct lightningd *ld, const tal_t *ctx)
 	t2 = wallet_payment_by_hash(ctx, w, &t->payment_hash);
 	CHECK(t2 != NULL);
 	CHECK(t2->status == t->status);
-	CHECK(node_id_cmp(&t2->destination, &t->destination) == 0);
+	CHECK(node_id_cmp(t2->destination, t->destination) == 0);
 	CHECK(amount_msat_eq(t2->msatoshi, t->msatoshi));
 	CHECK(amount_msat_eq(t2->msatoshi_sent, t->msatoshi_sent));
 	CHECK(!t2->payment_preimage);
@@ -1276,7 +1277,7 @@ static bool test_payment_crud(struct lightningd *ld, const tal_t *ctx)
 	t2 = wallet_payment_by_hash(ctx, w, &t->payment_hash);
 	CHECK(t2 != NULL);
 	CHECK(t2->status == t->status);
-	CHECK(node_id_eq(&t2->destination, &t->destination));
+	CHECK(node_id_eq(t2->destination, t->destination));
 	CHECK(amount_msat_eq(t2->msatoshi, t->msatoshi));
 	CHECK(amount_msat_eq(t2->msatoshi_sent, t->msatoshi_sent));
 	CHECK(preimage_eq(t->payment_preimage, t2->payment_preimage));

wallet/wallet.c

@@ -2129,7 +2129,12 @@ void wallet_payment_store(struct wallet *wallet,
 
 	db_bind_int(stmt, 0, payment->status);
 	db_bind_sha256(stmt, 1, &payment->payment_hash);
-	db_bind_node_id(stmt, 2, &payment->destination);
+
+	if (payment->destination != NULL)
+		db_bind_node_id(stmt, 2, payment->destination);
+	else
+		db_bind_null(stmt, 2);
+
 	db_bind_amount_msat(stmt, 3, &payment->msatoshi);
 	db_bind_int(stmt, 4, payment->timestamp);
 
@@ -2189,7 +2194,13 @@ static struct wallet_payment *wallet_stmt2payment(const tal_t *ctx,
 	payment->id = db_column_u64(stmt, 0);
 	payment->status = db_column_int(stmt, 1);
 
-	db_column_node_id(stmt, 2, &payment->destination);
+	if (!db_column_is_null(stmt, 2)) {
+		payment->destination = tal(payment, struct node_id);
+		db_column_node_id(stmt, 2, payment->destination);
+	} else {
+		payment->destination = NULL;
+	}
+
 	db_column_amount_msat(stmt, 3, &payment->msatoshi);
 	db_column_sha256(stmt, 4, &payment->payment_hash);
 

wallet/wallet.h

@@ -251,7 +251,9 @@ struct wallet_payment {
 	u32 timestamp;
 	struct sha256 payment_hash;
 	enum wallet_payment_status status;
-	struct node_id destination;
+
+	/* The destination may not be known if we used `sendonion` */
+	struct node_id *destination;
 	struct amount_msat msatoshi;
 	struct amount_msat msatoshi_sent;
 	/* If and only if PAYMENT_COMPLETE */