From f1cc82ae53e7c01a78b1dba10fa4a467bb359648 Mon Sep 17 00:00:00 2001
From: Robert Habermeier <rphmeier@gmail.com>
Date: Fri, 17 Aug 2018 22:13:01 +0200
Subject: [PATCH] Continue from next round when re-building on same block
 (#582)

* keep rounds consistent when encountering bad block

* fix interval logic

* Fixed indentation
---
 polkadot/consensus/src/service.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/polkadot/consensus/src/service.rs b/polkadot/consensus/src/service.rs
index d0d89786c3..d7360bb45a 100644
--- a/polkadot/consensus/src/service.rs
+++ b/polkadot/consensus/src/service.rs
@@ -164,7 +164,11 @@ impl Service {
 				interval.map_err(|e| debug!("Timer error: {:?}", e)).for_each(move |_| {
 					if let Ok(best_block) = c.best_block_header() {
 						let hash = best_block.hash();
-						if hash == prev_best && s.live_agreement() != Some(hash) {
+						let last_agreement = s.last_agreement();
+						let can_build_upon = last_agreement
+							.map_or(true, |x| !x.live || x.parent_hash != hash);
+
+						if hash == prev_best && can_build_upon {
 							debug!("Starting consensus round after a timeout");
 							start_bft(best_block, s.clone());
 						}