f - support downgrades

Author: jkczyz

lightning/src/events/mod.rs

@@ -1553,10 +1553,15 @@ impl Writeable for Event {
 			},
 			&Event::PaymentFailed { ref payment_id, ref payment_hash, ref reason } => {
 				15u8.write(writer)?;
+				let (payment_hash, invoice_received) = match payment_hash {
+					Some(payment_hash) => (payment_hash, true),
+					None => (&PaymentHash([0; 32]), false),
+				};
 				write_tlv_fields!(writer, {
 					(0, payment_id, required),
 					(1, reason, option),
-					(2, payment_hash, option),
+					(2, payment_hash, required),
+					(3, invoice_received, required),
 				})
 			},
 			&Event::OpenChannelRequest { .. } => {
@@ -1927,17 +1932,19 @@ impl MaybeReadable for Event {
 			},
 			15u8 => {
 				let mut f = || {
-					let mut payment_hash = None;
+					let mut payment_hash = PaymentHash([0; 32]);
 					let mut payment_id = PaymentId([0; 32]);
 					let mut reason = None;
+					let mut invoice_received = true;
 					read_tlv_fields!(reader, {
 						(0, payment_id, required),
 						(1, reason, upgradable_option),
-						(2, payment_hash, option),
+						(2, payment_hash, required),
+						(3, invoice_received, (default_value, true)),
 					});
 					Ok(Some(Event::PaymentFailed {
 						payment_id,
-						payment_hash,
+						payment_hash: invoice_received.then(|| payment_hash),
 						reason,
 					}))
 				};