From: Arik Sosman <git@arik.io>
Date: Sat, 4 Nov 2023 06:05:26 +0000 (-0700)
Subject: Include old updates when necessary.
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=3008d39976fdeeae1a417d15b5e8aa651a72b4eb;p=rapid-gossip-sync-server

Include old updates when necessary.

When a channel has only recently become bidirectional,
but there has not been a new update in the old direction
since the last sync, the latest update in the old direction
must still be included in full because it is the first time
the full channel is being snapshotted.
---

diff --git a/src/serialization.rs b/src/serialization.rs
index 93bd381..7e58b02 100644
--- a/src/serialization.rs
+++ b/src/serialization.rs
@@ -187,6 +187,10 @@ pub(super) fn serialize_delta_set(delta_set: DeltaSet, last_sync_timestamp: u32)
 						record_full_update_in_histograms(&latest_update);
 						serialization_set.updates.push(UpdateSerialization::Full(latest_update));
 					}
+				} else if is_newly_included_announcement {
+					if let Some(unannounced_update) = updates.last_update_before_seen {
+						serialization_set.updates.push(UpdateSerialization::Full(unannounced_update.update));
+					}
 				} else if let Some(flags) = updates.serialization_update_flags {
 					serialization_set.updates.push(UpdateSerialization::Reminder(scid, flags));
 				}