From: Matt Corallo <git@bluematt.me>
Date: Fri, 5 May 2023 03:33:54 +0000 (+0000)
Subject: Document when `PaymentPathSuccessful::payment_hash` is filled in.
X-Git-Tag: v0.0.116-alpha1~49^2~1
X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=e1394f3ea04816ee5cf7d155702581363328dfb5;p=rust-lightning

Document when `PaymentPathSuccessful::payment_hash` is filled in.

The `payment_hash` field in `PaymentPathSuccessful` is always
`Some` as long as the pening payment tracker has a `payment_hash`,
which is true for all `Pending` payments as well as all `Fulfilled`
payments starting with the commit which added
`PaymentPathSuccessful` -
3b5c370b404e2f5a8f3c35093b97406f149a9340c177c05252574083d68df0da.
---

diff --git a/lightning/src/events/mod.rs b/lightning/src/events/mod.rs
index 4d8b8cee9..046eb22f7 100644
--- a/lightning/src/events/mod.rs
+++ b/lightning/src/events/mod.rs
@@ -498,6 +498,8 @@ pub enum Event {
 		payment_id: PaymentId,
 		/// The hash that was given to [`ChannelManager::send_payment`].
 		///
+		/// This will be `Some` for all payments which completed on LDK 0.0.104 or later.
+		///
 		/// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 		payment_hash: Option<PaymentHash>,
 		/// The payment path that was successful.
diff --git a/lightning/src/ln/outbound_payment.rs b/lightning/src/ln/outbound_payment.rs
index 569e664ba..f107f3b55 100644
--- a/lightning/src/ln/outbound_payment.rs
+++ b/lightning/src/ln/outbound_payment.rs
@@ -60,6 +60,7 @@ pub(crate) enum PendingOutboundPayment {
 	/// and add a pending payment that was already fulfilled.
 	Fulfilled {
 		session_privs: HashSet<[u8; 32]>,
+		/// Filled in for any payment which moved to `Fulfilled` on LDK 0.0.104 or later.
 		payment_hash: Option<PaymentHash>,
 		timer_ticks_without_htlcs: u8,
 	},
@@ -1168,9 +1169,11 @@ impl OutboundPayments {
 				if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
 					assert!(payment.get().is_fulfilled());
 					if payment.get_mut().remove(&session_priv_bytes, None) {
+						let payment_hash = payment.get().payment_hash();
+						debug_assert!(payment_hash.is_some());
 						pending_events.push_back((events::Event::PaymentPathSuccessful {
 							payment_id,
-							payment_hash: payment.get().payment_hash(),
+							payment_hash,
 							path,
 						}, None));
 					}