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 d28066ec4131b429f70e7e16b8ed843f9e014265..0ed09a366d8be7075415b92abad585a51fad6c9b 100644 (file)
--- 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 (file)
index 0000000..f8967f1
--- /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.