From 01ac7ad23c36be08e11b02b4859c70e67877bf1d Mon Sep 17 00:00:00 2001
From: Emilia Hane <emiliaha95@gmail.com>
Date: Thu, 5 Jan 2023 10:17:59 +0100
Subject: [PATCH] Return empty blobs sidecar when no kzg commitments in block

---
 beacon_node/beacon_chain/src/beacon_chain.rs | 23 +++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index dd2be88b0..3ecccd1cc 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -1052,7 +1052,28 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         &self,
         block_root: &Hash256,
     ) -> Result<Option<BlobsSidecar<T::EthSpec>>, Error> {
-        Ok(self.store.get_blobs(block_root)?)
+        match self.store.get_blobs(block_root)? {
+            Some(blobs) => Ok(Some(blobs)),
+            None => {
+                if let Some(block) = self.get_block(block_root).await? {
+                    let expected_kzg_commitments = block.message().body().blob_kzg_commitments()?;
+
+                    if expected_kzg_commitments.len() > 0 {
+                        Err(Error::DBInconsistent(format!(
+                            "expected kzg_commitments but no blobs stored for block_root {}",
+                            block_root
+                        )))
+                    } else {
+                        Ok(Some(BlobsSidecar::empty_from_parts(
+                            *block_root,
+                            block.slot(),
+                        )))
+                    }
+                } else {
+                    Ok(None)
+                }
+            }
+        }
     }
 
     pub fn get_blinded_block(