From cd676d5621069050d6ceebef3c562ee46fd18de4 Mon Sep 17 00:00:00 2001
From: mjkeating <michael.j.keating@gmail.com>
Date: Mon, 18 Feb 2019 11:55:44 -0800
Subject: [PATCH] fixed a bug in TreeHash.rs/list_to_blob

---
 eth2/utils/ssz/src/tree_hash.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/eth2/utils/ssz/src/tree_hash.rs b/eth2/utils/ssz/src/tree_hash.rs
index 3f190e32ed..bb05f01db7 100644
--- a/eth2/utils/ssz/src/tree_hash.rs
+++ b/eth2/utils/ssz/src/tree_hash.rs
@@ -55,8 +55,13 @@ fn list_to_blob(list: &mut Vec<Vec<u8>>) -> (usize, Vec<u8>) {
         list[0].len()
     };
 
-    let items_per_chunk = SSZ_CHUNK_SIZE / list[0].len();
-    let chunk_count = list.len() / items_per_chunk;
+    let (items_per_chunk, chunk_count) = if list.is_empty() {
+        (1, 1)
+    } else {
+        let items_per_chunk = SSZ_CHUNK_SIZE / list[0].len();
+        let chunk_count = list.len() / items_per_chunk;
+        (items_per_chunk, chunk_count)
+    };
 
     let mut chunkz = Vec::new();
     if list.is_empty() {