From 706c7e0206c790f5c74bfe779d8aa67152a56a42 Mon Sep 17 00:00:00 2001
From: dapplion <35266934+dapplion@users.noreply.github.com>
Date: Sun, 31 May 2026 18:40:00 +0200
Subject: [PATCH] Use correct slot in custody request

---
 .../sync/block_lookups/single_block_lookup.rs | 11 ++++++++--
 .../network/src/sync/network_context.rs       | 22 +++----------------
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs b/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
index 2febc4cd4e..21dcfb44fc 100644
--- a/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
+++ b/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
@@ -288,6 +288,7 @@ enum DataDownload<E: EthSpec> {
     },
     Columns {
         block_root: Hash256,
+        slot: Slot,
         state: SingleLookupRequestState<DataColumnSidecarList<E>>,
     },
 }
@@ -309,9 +310,13 @@ impl<E: EthSpec> DataDownload<E> {
                 let eb = *expected_blobs;
                 state.make_request(|| cx.blob_lookup_request(id, peers, br, eb))
             }
-            DataDownload::Columns { block_root, state } => {
+            DataDownload::Columns {
+                block_root,
+                slot,
+                state,
+            } => {
                 let br = *block_root;
-                state.make_request(|| cx.custody_lookup_request(id, br, peers))
+                state.make_request(|| cx.custody_lookup_request(id, br, *slot, peers))
             }
         }
     }
@@ -447,6 +452,7 @@ impl<E: EthSpec> DataRequestState<E> {
                 if expected_blobs > 0 {
                     Self::Downloading(DataDownload::Columns {
                         block_root,
+                        slot,
                         state: SingleLookupRequestState::new_with_processing_failures(
                             failed_processing,
                         ),
@@ -459,6 +465,7 @@ impl<E: EthSpec> DataRequestState<E> {
                 if expected_blobs > 0 {
                     Self::Downloading(DataDownload::Columns {
                         block_root,
+                        slot,
                         state: SingleLookupRequestState::new_with_processing_failures(
                             failed_processing,
                         ),
diff --git a/beacon_node/network/src/sync/network_context.rs b/beacon_node/network/src/sync/network_context.rs
index 86435dd549..a987fd94f6 100644
--- a/beacon_node/network/src/sync/network_context.rs
+++ b/beacon_node/network/src/sync/network_context.rs
@@ -1179,34 +1179,18 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
         &mut self,
         lookup_id: SingleLookupId,
         block_root: Hash256,
+        block_slot: Slot,
         lookup_peers: Arc<RwLock<HashSet<PeerId>>>,
     ) -> Result<LookupRequestResult, RpcRequestSendError> {
-        let slot = self
-            .chain
-            .canonical_head
-            .fork_choice_read_lock()
-            .get_block(&block_root)
-            .map(|block| block.slot)
-            .or_else(|| self.chain.slot().ok())
-            .ok_or_else(|| {
-                RpcRequestSendError::InternalError(format!(
-                    "Unable to determine slot for block {block_root:?}"
-                ))
-            })?;
-
         let custody_indexes_imported = self
             .chain
-            .cached_data_column_indexes(&block_root, slot)
+            .cached_data_column_indexes(&block_root, block_slot)
             .unwrap_or_default();
 
-        let current_epoch = self.chain.epoch().map_err(|e| {
-            RpcRequestSendError::InternalError(format!("Unable to read slot clock {:?}", e))
-        })?;
-
         // Include only the blob indexes not yet imported (received through gossip)
         let mut custody_indexes_to_fetch = self
             .chain
-            .sampling_columns_for_epoch(current_epoch)
+            .sampling_columns_for_epoch(block_slot.epoch(T::EthSpec::slots_per_epoch()))
             .iter()
             .copied()
             .filter(|index| !custody_indexes_imported.contains(index))