Fix upgradable_required fields to actually be required in lower level macros

[rust-lightning] / lightning / src / util / ser.rs

diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs
index 36b64b63900b575c477444b43a51d94c25faf051..5adf5758131bb65e9929042a267162e3665c58e2 100644 (file)
--- a/lightning/src/util/ser.rs
+++ b/lightning/src/util/ser.rs
@@ -303,6 +303,18 @@ impl<T: Readable> From<T> for RequiredWrapper<T> {
        fn from(t: T) -> RequiredWrapper<T> { RequiredWrapper(Some(t)) }
 }
 
+/// Wrapper to read a required (non-optional) TLV record that may have been upgraded without
+/// backwards compat.
+pub struct UpgradableRequired<T: MaybeReadable>(pub Option<T>);
+impl<T: MaybeReadable> MaybeReadable for UpgradableRequired<T> {
+       #[inline]
+       fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
+               let tlv = MaybeReadable::read(reader)?;
+               if let Some(tlv) = tlv { return Ok(Some(Self(Some(tlv)))) }
+               Ok(None)
+       }
+}
+
 pub(crate) struct U48(pub u64);
 impl Writeable for U48 {
        #[inline]