From f288a18b0c03e8c753957c1857574692678e6c74 Mon Sep 17 00:00:00 2001
From: Yeastplume <yeastplume@gmail.com>
Date: Wed, 31 Jan 2018 10:56:41 +0000
Subject: [PATCH] minor test fix (#669)

---
 core/src/global.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/core/src/global.rs b/core/src/global.rs
index 1e4cb6307..00aa43c7d 100644
--- a/core/src/global.rs
+++ b/core/src/global.rs
@@ -224,7 +224,12 @@ pub fn difficulty_data_to_vector<T>(cursor: T) -> Vec<Result<(u64, Difficulty),
 			.map(|b| (b.clone().unwrap().0, b.clone().unwrap().1))
 			.collect();
 		for i in (1..live_intervals.len()).rev() {
-			live_intervals[i].0=live_intervals[i].0-live_intervals[i-1].0;
+			// prevents issues with very fast automated test chains
+			if live_intervals[i-1].0 > live_intervals[i].0 {
+				live_intervals[i].0 = 0;
+			} else {
+				live_intervals[i].0=live_intervals[i].0-live_intervals[i-1].0;
+			}
 		}
 		// 
 		// Remove genesis "interval"