From 65bb2836be807a1f4cf1e3cf926a15e906b01488 Mon Sep 17 00:00:00 2001
From: Stefan <22667037+qu0b@users.noreply.github.com>
Date: Mon, 2 Feb 2026 11:12:22 +0100
Subject: [PATCH] fix: set slot_number to latest_block_header.slot in Gloas
 fork upgrade (#8726)
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During the Fulu→Gloas state upgrade, the latestExecutionPayloadHeader's
slot_number was hardcoded to 0. This caused beacon state root divergence
between Lighthouse and Lodestar at the Gloas fork boundary (slot 8).

Set slot_number to pre.latest_block_header.slot to match Lodestar's
behavior and correctly carry forward the slot of the last block.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
---
 consensus/state_processing/src/upgrade/gloas.rs           | 4 +++-
 consensus/types/src/execution/execution_payload_header.rs | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/consensus/state_processing/src/upgrade/gloas.rs b/consensus/state_processing/src/upgrade/gloas.rs
index 50b78ecb05..5c9f5ccc24 100644
--- a/consensus/state_processing/src/upgrade/gloas.rs
+++ b/consensus/state_processing/src/upgrade/gloas.rs
@@ -64,7 +64,9 @@ pub fn upgrade_state_to_gloas<E: EthSpec>(
         current_sync_committee: pre.current_sync_committee.clone(),
         next_sync_committee: pre.next_sync_committee.clone(),
         // Execution - upgrade header from Fulu to Gloas
-        latest_execution_payload_header: pre.latest_execution_payload_header.upgrade_to_gloas(),
+        latest_execution_payload_header: pre
+            .latest_execution_payload_header
+            .upgrade_to_gloas(pre.latest_block_header.slot.into()),
         // Capella
         next_withdrawal_index: pre.next_withdrawal_index,
         next_withdrawal_validator_index: pre.next_withdrawal_validator_index,
diff --git a/consensus/types/src/execution/execution_payload_header.rs b/consensus/types/src/execution/execution_payload_header.rs
index 06a8e11c34..b262767887 100644
--- a/consensus/types/src/execution/execution_payload_header.rs
+++ b/consensus/types/src/execution/execution_payload_header.rs
@@ -275,7 +275,7 @@ impl<E: EthSpec> ExecutionPayloadHeaderElectra<E> {
 }
 
 impl<E: EthSpec> ExecutionPayloadHeaderFulu<E> {
-    pub fn upgrade_to_gloas(&self) -> ExecutionPayloadHeaderGloas<E> {
+    pub fn upgrade_to_gloas(&self, slot_number: u64) -> ExecutionPayloadHeaderGloas<E> {
         ExecutionPayloadHeaderGloas {
             parent_hash: self.parent_hash,
             fee_recipient: self.fee_recipient,
@@ -295,7 +295,7 @@ impl<E: EthSpec> ExecutionPayloadHeaderFulu<E> {
             blob_gas_used: self.blob_gas_used,
             excess_blob_gas: self.excess_blob_gas,
             block_access_list_root: Hash256::zero(),
-            slot_number: 0,
+            slot_number,
         }
     }
 }