From 74597bd15a11c5ff7b34621a962969f5d721b0bf Mon Sep 17 00:00:00 2001 From: moneromooo-monero Date: Sun, 6 Aug 2017 16:56:51 +0100 Subject: wallet2: improve refresh height determination As reported by jaquee, the calculation could underflow for very low heights. Additionally, we now use the target height too. --- src/wallet/wallet2.cpp | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp index 6b1026a55..3337206ab 100644 --- a/src/wallet/wallet2.cpp +++ b/src/wallet/wallet2.cpp @@ -2174,9 +2174,26 @@ crypto::secret_key wallet2::generate(const std::string& wallet_, const std::stri // try asking the daemon first if(m_refresh_from_block_height == 0 && !recover){ std::string err; - uint64_t height = get_daemon_blockchain_height(err); - if (err.empty()) - m_refresh_from_block_height = height - blocks_per_month; + uint64_t height = 0; + + // we get the max of approximated height and known height + // approximated height is the least of daemon target height + // (the max of what the other daemons are claiming is their + // height) and the theoretical height based on the local + // clock. This will be wrong only if both the local clock + // is bad *and* a peer daemon claims a highest height than + // the real chain. + // known height is the height the local daemon is currently + // synced to, it will be lower than the real chain height if + // the daemon is currently syncing. + height = get_approximate_blockchain_height(); + uint64_t target_height = get_daemon_blockchain_target_height(err); + if (err.empty() && target_height < height) + height = target_height; + uint64_t local_height = get_daemon_blockchain_height(err); + if (err.empty() && local_height > height) + height = local_height; + m_refresh_from_block_height = height >= blocks_per_month ? height - blocks_per_month : 0; } if(m_refresh_from_block_height == 0 && !recover){ -- cgit v1.2.3