From fab6d6b2d154893ab422dda87f3535d42c3e06f4 Mon Sep 17 00:00:00 2001
From: MarcoFalke <falke.marco@gmail.com>
Date: Tue, 23 Nov 2021 19:49:48 +0100
Subject: [PATCH] Move pindexBestInvalid to ChainstateManager

A private member is better than a global.
---
 src/validation.cpp | 28 +++++++++++++---------------
 src/validation.h   |  3 +++
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/validation.cpp b/src/validation.cpp
index ba6b9e853a..27af75245f 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -133,11 +133,6 @@ arith_uint256 nMinimumChainWork;
 
 CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
 
-// Internal stuff
-namespace {
-    CBlockIndex* pindexBestInvalid = nullptr;
-} // namespace
-
 // Internal stuff from blockstorage ...
 extern RecursiveMutex cs_LastBlockFile;
 extern std::vector<CBlockFileInfo> vinfoBlockFile;
@@ -1257,7 +1252,7 @@ void CChainState::CheckForkWarningConditions()
         return;
     }
 
-    if (pindexBestInvalid && pindexBestInvalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) {
+    if (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) {
         LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n", __func__);
         SetfLargeWorkInvalidChainFound(true);
     } else {
@@ -1268,8 +1263,9 @@ void CChainState::CheckForkWarningConditions()
 // Called both upon regular invalid block discovery *and* InvalidateBlock
 void CChainState::InvalidChainFound(CBlockIndex* pindexNew)
 {
-    if (!pindexBestInvalid || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
-        pindexBestInvalid = pindexNew;
+    if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
+        m_chainman.m_best_invalid = pindexNew;
+    }
     if (pindexBestHeader != nullptr && pindexBestHeader->GetAncestor(pindexNew->nHeight) == pindexNew) {
         pindexBestHeader = m_chain.Tip();
     }
@@ -2432,8 +2428,9 @@ CBlockIndex* CChainState::FindMostWorkChain() {
             bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA);
             if (fFailedChain || fMissingData) {
                 // Candidate chain is not usable (either invalid or missing data)
-                if (fFailedChain && (pindexBestInvalid == nullptr || pindexNew->nChainWork > pindexBestInvalid->nChainWork))
-                    pindexBestInvalid = pindexNew;
+                if (fFailedChain && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) {
+                    m_chainman.m_best_invalid = pindexNew;
+                }
                 CBlockIndex *pindexFailed = pindexNew;
                 // Remove the entire chain from the set.
                 while (pindexTest != pindexFailed) {
@@ -2885,9 +2882,9 @@ void CChainState::ResetBlockFailureFlags(CBlockIndex *pindex) {
             if (it->second->IsValid(BLOCK_VALID_TRANSACTIONS) && it->second->HaveTxsDownloaded() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), it->second)) {
                 setBlockIndexCandidates.insert(it->second);
             }
-            if (it->second == pindexBestInvalid) {
+            if (it->second == m_chainman.m_best_invalid) {
                 // Reset invalid block marker if it was pointing to one of those.
-                pindexBestInvalid = nullptr;
+                m_chainman.m_best_invalid = nullptr;
             }
             m_chainman.m_failed_blocks.erase(it->second);
         }
@@ -3792,8 +3789,9 @@ bool BlockManager::LoadBlockIndex(
                 }
             }
         }
-        if (pindex->nStatus & BLOCK_FAILED_MASK && (!pindexBestInvalid || pindex->nChainWork > pindexBestInvalid->nChainWork))
-            pindexBestInvalid = pindex;
+        if (pindex->nStatus & BLOCK_FAILED_MASK && (!chainman.m_best_invalid || pindex->nChainWork > chainman.m_best_invalid->nChainWork)) {
+            chainman.m_best_invalid = pindex;
+        }
         if (pindex->pprev)
             pindex->BuildSkip();
         if (pindex->IsValid(BLOCK_VALID_TREE) && (pindexBestHeader == nullptr || CBlockIndexWorkComparator()(pindexBestHeader, pindex)))
@@ -4141,7 +4139,6 @@ void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman)
 {
     LOCK(cs_main);
     chainman.Unload();
-    pindexBestInvalid = nullptr;
     pindexBestHeader = nullptr;
     if (mempool) mempool->clear();
     vinfoBlockFile.clear();
@@ -5120,6 +5117,7 @@ void ChainstateManager::Unload()
 
     m_failed_blocks.clear();
     m_blockman.Unload();
+    m_best_invalid = nullptr;
 }
 
 void ChainstateManager::Reset()
diff --git a/src/validation.h b/src/validation.h
index 3a702b4fa6..784ff0b3bc 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -866,6 +866,9 @@ private:
     //! by the background validation chainstate.
     bool m_snapshot_validated{false};
 
+    CBlockIndex* m_best_invalid;
+    friend bool BlockManager::LoadBlockIndex(const Consensus::Params&, ChainstateManager&);
+
     //! Internal helper for ActivateSnapshot().
     [[nodiscard]] bool PopulateAndValidateSnapshot(
         CChainState& snapshot_chainstate,