From 3387d82a9c1b438dd298a3048c722d4d1b9fc29b Mon Sep 17 00:00:00 2001
From: Gav Wood <i@gavwood.com>
Date: Tue, 6 Jan 2015 20:12:54 +0100
Subject: [PATCH] More efficient getLastHashes.

---
 libethereum/State.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libethereum/State.cpp b/libethereum/State.cpp
index c6a6ce125..e0705859f 100644
--- a/libethereum/State.cpp
+++ b/libethereum/State.cpp
@@ -1006,9 +1006,9 @@ LastHashes State::getLastHashes(BlockChain const& _bc) const
 	ret.resize(256);
 	if (c_protocolVersion > 49)
 	{
-		unsigned n = (unsigned)m_previousBlock.number;
-		for (unsigned i = 0; i < 256; ++i)
-			ret[i] = _bc.numberHash(std::max<unsigned>(n, i) - i);
+		ret[0] = _bc.currentHash();
+		for (unsigned i = 1; i < 256; ++i)
+			ret[i] = ret[i - 1] ? _bc.details(ret[i - 1]).parent : h256();
 	}
 	return ret;
 }