From: Valentine Wallace <vwallace@protonmail.com>
Date: Mon, 18 Mar 2024 21:01:07 +0000 (-0400)
Subject: Make blinded hop features optional per spec.
X-Git-Tag: v0.0.123-beta~38^2
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=18ebbf72446e8c45fdfc5ae73a1c3b55d8f97377;p=rust-lightning

Make blinded hop features optional per spec.

The spec states that if these features are missing, we MUST process the message
as if it were present and contained an empty array.
---

diff --git a/lightning/src/blinded_path/payment.rs b/lightning/src/blinded_path/payment.rs
index d28066ec4..0ed09a366 100644
--- a/lightning/src/blinded_path/payment.rs
+++ b/lightning/src/blinded_path/payment.rs
@@ -169,7 +169,7 @@ impl Readable for BlindedPaymentTlvs {
 				short_channel_id,
 				payment_relay: payment_relay.ok_or(DecodeError::InvalidValue)?,
 				payment_constraints: payment_constraints.0.unwrap(),
-				features: features.ok_or(DecodeError::InvalidValue)?,
+				features: features.unwrap_or_else(BlindedHopFeatures::empty),
 			}))
 		} else {
 			if payment_relay.is_some() || features.is_some() { return Err(DecodeError::InvalidValue) }
diff --git a/pending_changelog/blinded-hop-features-optional.txt b/pending_changelog/blinded-hop-features-optional.txt
new file mode 100644
index 000000000..f8967f127
--- /dev/null
+++ b/pending_changelog/blinded-hop-features-optional.txt
@@ -0,0 +1,5 @@
+## Bug Fixes
+
+* LDK previously would fail to forward an intermediate blinded payment
+	if the blinded hop features were absent, potentially breaking
+	interoperability.