wallet: allow saving forwarding scid even if we don't have amount.

They're not logically connected: we can know where they wanted to
go, but we didn't send it.

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

wallet/wallet.c

@@ -4325,22 +4325,26 @@ void wallet_forwarded_payment_add(struct wallet *w, const struct htlc_in *in,
 				 ") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);"));
 	db_bind_u64(stmt, 0, in->dbid);
 
-	if (out) {
-		db_bind_u64(stmt, 1, out->dbid);
-		db_bind_u64(stmt, 3, out->key.channel->scid->u64);
-		db_bind_amount_msat(stmt, 5, &out->msat);
-	} else {
-		/* FORWARD_LOCAL_FAILED may occur before we get htlc_out */
+	/* FORWARD_LOCAL_FAILED may occur before we get htlc_out */
+	if (!out || !scid_out) {
 		assert(failcode != 0);
 		assert(state == FORWARD_LOCAL_FAILED);
-		db_bind_null(stmt, 1);
-		db_bind_null(stmt, 3);
-		db_bind_null(stmt, 5);
 	}
 
+	if (out)
+		db_bind_u64(stmt, 1, out->dbid);
+	else
+		db_bind_null(stmt, 1);
 	db_bind_u64(stmt, 2, in->key.channel->scid->u64);
-
+	if (scid_out)
+		db_bind_u64(stmt, 3, scid_out->u64);
+	else
+		db_bind_null(stmt, 3);
 	db_bind_amount_msat(stmt, 4, &in->msat);
+	if (out)
+		db_bind_amount_msat(stmt, 5, &out->msat);
+	else
+		db_bind_null(stmt, 5);
 
 	db_bind_int(stmt, 6, wallet_forward_status_in_db(state));
 	db_bind_timeabs(stmt, 7, in->received_time);