From 8da9dd0725ea90b1fd085d9551177fe62d7a9ba2 Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jgarzik@bitpay.com>
Date: Mon, 10 Jun 2013 09:38:13 -0400
Subject: [PATCH] Wallet: optimize rescan to skip blocks prior to birthday

---
 src/wallet.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/wallet.cpp b/src/wallet.cpp
index aa1371111..9a4a92cd5 100644
--- a/src/wallet.cpp
+++ b/src/wallet.cpp
@@ -790,6 +790,13 @@ int CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
         LOCK(cs_wallet);
         while (pindex)
         {
+            // no need to read and scan block, if block was created before
+            // our wallet birthday (as adjusted for block time variability)
+            if (nTimeFirstKey && (pindex->nTime < (nTimeFirstKey - 7200))) {
+                pindex = pindex->GetNextInMainChain();
+                continue;
+            }
+
             CBlock block;
             block.ReadFromDisk(pindex);
             BOOST_FOREACH(CTransaction& tx, block.vtx)