From 65b7702efec6735d39f5e4a5cf8092629f4f80ea Mon Sep 17 00:00:00 2001
From: Dan Cline <6798349+Rjected@users.noreply.github.com>
Date: Thu, 18 May 2023 05:03:51 -0400
Subject: [PATCH] fix: return latestValidHash from sidechains (#2725)

---
 crates/consensus/beacon/src/engine/mod.rs | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/crates/consensus/beacon/src/engine/mod.rs b/crates/consensus/beacon/src/engine/mod.rs
index d82668d97d..ec39970212 100644
--- a/crates/consensus/beacon/src/engine/mod.rs
+++ b/crates/consensus/beacon/src/engine/mod.rs
@@ -276,11 +276,13 @@ where
             return Some(H256::zero())
         }
 
-        // TODO(mattsse): This could be invoked on new payload which does not make tree canonical,
-        //  which would make this inaccurate, e.g. if an invalid payload is received in this
-        //  scenario: FUC (unknown head) -> valid payload  -> invalid payload
-
-        self.blockchain.find_canonical_ancestor(parent_hash)
+        // If this is sent from new payload then the parent hash could be in a side chain, and is
+        // not necessarily canonical
+        if self.blockchain.header_by_hash(parent_hash).is_some() {
+            Some(parent_hash)
+        } else {
+            self.blockchain.find_canonical_ancestor(parent_hash)
+        }
     }
 
     /// Loads the header for the given `block_number` from the database.