From 4854f6923b57d6f86b388f56c0f06a5a2316f3c0 Mon Sep 17 00:00:00 2001
From: arkpar <arkady.paronyan@gmail.com>
Date: Sat, 26 Mar 2016 12:00:05 +0100
Subject: [PATCH] Full restart on bad block

---
 sync/src/chain.rs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/sync/src/chain.rs b/sync/src/chain.rs
index 81fd5f9ab..16bc41b70 100644
--- a/sync/src/chain.rs
+++ b/sync/src/chain.rs
@@ -282,7 +282,6 @@ impl ChainSync {
 		self.peers.clear();
 	}
 
-
 	#[cfg_attr(feature="dev", allow(for_kv_map))] // Because it's not possible to get `values_mut()`
 	/// Rest sync. Clear all downloaded data but keep the queue
 	fn reset(&mut self) {
@@ -309,6 +308,13 @@ impl ChainSync {
 		self.state = SyncState::NotSynced;
 	}
 
+	/// Restart sync after bad block has been detected. May end up re-downloading up to QUEUE_SIZE blocks
+	pub fn restart_on_bad_block(&mut self, io: &mut SyncIo) {
+		self.restart(io);
+		// Do not assume that the block queue/chain still has our last_imported_block
+		self.last_imported_block = None;
+		self.last_imported_hash = None;
+	}
 	/// Called by peer to report status
 	fn on_peer_status(&mut self, io: &mut SyncIo, peer_id: PeerId, r: &UntrustedRlp) -> Result<(), PacketDecodeError> {
 		let peer = PeerInfo {
@@ -846,7 +852,7 @@ impl ChainSync {
 		}
 
 		if restart {
-			self.restart(io);
+			self.restart_on_bad_block(io);
 			return;
 		}