eth/downloader: handle missing withdrawals if empty list is expected (#26675)

This PR relaxes the block body ingress handling a bit: if block body withdrawals are missing (but expected to be empty), the body withdrawals are set to 'empty list' before being passed to upper layers. 

This fixes an issue where a block passed from EthereumJS to geth was deemed invalid.

eth/downloader/queue.go

@@ -783,6 +783,10 @@ func (q *queue) DeliverBodies(id string, txLists [][]*types.Transaction, txListH
 		if header.WithdrawalsHash == nil {
 			// discard any withdrawals if we don't have a withdrawal hash set
 			withdrawalLists[index] = nil
+		} else if *header.WithdrawalsHash == types.EmptyRootHash && withdrawalLists[index] == nil {
+			// if the withdrawal hash is the emptyRootHash,
+			// we expect withdrawals to be [] instead of nil
+			withdrawalLists[index] = make([]*types.Withdrawal, 0)
 		} else if withdrawalListHashes[index] != *header.WithdrawalsHash {
 			return errInvalidBody
 		}

eth/protocols/eth/handler_test.go

@@ -424,7 +424,7 @@ func testGetBlockBodies(t *testing.T, protocol uint) {
 			RequestId:         123,
 			BlockBodiesPacket: bodies,
 		}); err != nil {
-			t.Errorf("test %d: bodies mismatch: %v", i, err)
+			t.Fatalf("test %d: bodies mismatch: %v", i, err)
 		}
 	}
 }