From 706428acbe134d54553bf3fb52bfcd344c707e11 Mon Sep 17 00:00:00 2001
From: Gav Wood <i@gavwood.com>
Date: Wed, 2 Dec 2015 02:44:45 +0100
Subject: [PATCH] Random tests.

---
 src/triehash.rs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/triehash.rs b/src/triehash.rs
index afc07a7bf..33d35513c 100644
--- a/src/triehash.rs
+++ b/src/triehash.rs
@@ -190,9 +190,12 @@ fn hash256rlp(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStre
 	// iterate over all possible nibbles
 	for i in 0..16 {
 		// cout how many successive elements have same next nibble
-		let len = input[begin..].iter()
-			.map(| pair | pair.0[pre_len] )
-			.take_while(|&q| q == i).count();
+		let len = match begin < input.len() {
+			true => input[begin..].iter()
+				.map(| pair | pair.0[pre_len] )
+				.take_while(|&q| q == i).count(),
+			false => 0
+		};
 			
 		// if at least 1 successive element has the same nibble
 		// append their suffixes