From 87c06d4091b9ed42da5cef0f12d9334e48b1a959 Mon Sep 17 00:00:00 2001
From: Gregory Sanders <gsanders87@gmail.com>
Date: Wed, 27 Mar 2019 13:54:19 -0400
Subject: [PATCH 1/2] Save some space, maintain compatibility with
 elements-0.14 header index

---
 src/chain.h  | 12 ++++++------
 src/txdb.cpp |  1 -
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/chain.h b/src/chain.h
index d844af29f4..0e813557d9 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -210,7 +210,6 @@ class CBlockIndex
     int32_t nVersion;
     uint256 hashMerkleRoot;
     uint32_t nTime;
-    uint32_t block_height;
     uint32_t nBits;
     uint32_t nNonce;
     CProof proof;
@@ -240,7 +239,6 @@ class CBlockIndex
         nVersion       = 0;
         hashMerkleRoot = uint256();
         nTime          = 0;
-        block_height   = 0;
         nBits          = 0;
         nNonce         = 0;
         proof.SetNull();
@@ -258,7 +256,6 @@ class CBlockIndex
         nVersion       = block.nVersion;
         hashMerkleRoot = block.hashMerkleRoot;
         nTime          = block.nTime;
-        block_height   = block.block_height;
         nBits          = block.nBits;
         nNonce         = block.nNonce;
         proof          = block.proof;
@@ -290,7 +287,9 @@ class CBlockIndex
             block.hashPrevBlock = pprev->GetBlockHash();
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime          = nTime;
-        block.block_height   = block_height;
+        if (g_con_blockheightinheader) {
+            block.block_height = nHeight;
+        }
         block.nBits          = nBits;
         block.nNonce         = nNonce;
         block.proof          = proof;
@@ -411,7 +410,6 @@ class CDiskBlockIndex : public CBlockIndex
         READWRITE(hashPrev);
         READWRITE(hashMerkleRoot);
         READWRITE(nTime);
-        READWRITE(block_height);
         // For compatibility with elements 0.14 based chains
         if (g_signed_blocks) {
             READWRITE(proof);
@@ -428,7 +426,9 @@ class CDiskBlockIndex : public CBlockIndex
         block.hashPrevBlock   = hashPrev;
         block.hashMerkleRoot  = hashMerkleRoot;
         block.nTime           = nTime;
-        block.block_height    = block_height;
+        if (g_con_blockheightinheader) {
+            block.block_height = nHeight;
+        }
         block.nBits           = nBits;
         block.nNonce          = nNonce;
         block.proof           = proof;
diff --git a/src/txdb.cpp b/src/txdb.cpp
index da4a63a905..7871f86b66 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -307,7 +307,6 @@ bool CBlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams,
                 CBlockIndex* pindexNew = insertBlockIndex(diskindex.GetBlockHash());
                 pindexNew->pprev          = insertBlockIndex(diskindex.hashPrev);
                 pindexNew->nHeight        = diskindex.nHeight;
-                pindexNew->block_height   = diskindex.block_height;
                 pindexNew->nFile          = diskindex.nFile;
                 pindexNew->nDataPos       = diskindex.nDataPos;
                 pindexNew->nUndoPos       = diskindex.nUndoPos;

From 0baa13581e373133b7405eb700b42fce1b23c704 Mon Sep 17 00:00:00 2001
From: Gregory Sanders <gsanders87@gmail.com>
Date: Wed, 27 Mar 2019 14:42:27 -0400
Subject: [PATCH 2/2] Only check 1 in 1000 block header sigs on load

---
 src/txdb.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/txdb.cpp b/src/txdb.cpp
index 7871f86b66..5aac7860fb 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -320,7 +320,9 @@ bool CBlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams,
                 pindexNew->nTx            = diskindex.nTx;
 
                 const uint256 block_hash = pindexNew->GetBlockHash();
-                if (!CheckProof(pindexNew->GetBlockHeader(), consensusParams) &&
+                // Only validate one of every 1000 block header for sanity check
+                if (pindexNew->nHeight % 1000 == 0 &&
+                        !CheckProof(pindexNew->GetBlockHeader(), consensusParams) &&
                     block_hash != consensusParams.hashGenesisBlock) {
                     return error("%s: CheckProof: %s, %s", __func__, block_hash.ToString(), pindexNew->ToString());
                 }