Compute missing_columns correctly (#8425)

N/A


  The difference is computed by taking the difference of expected with received. We were doing the inverse.

Thanks to Yassine for finding the issue.


Co-Authored-By: Pawan Dhananjay <pawandhananjay@gmail.com>

beacon_node/network/src/sync/range_data_column_batch_request.rs

@@ -268,8 +268,8 @@ impl<T: BeaconChainTypes> RangeDataColumnBatchRequest<T> {
 
             let received_columns = columns.iter().map(|c| c.index).collect::<HashSet<_>>();
 
-            let missing_columns = received_columns
-                .difference(expected_custody_columns)
+            let missing_columns = expected_custody_columns
+                .difference(&received_columns)
                 .collect::<HashSet<_>>();
 
             // blobs are expected for this slot but there is at least one missing columns