From fd0d0e6c750cf8e9ddb82ff8e1c9d7e0a283d220 Mon Sep 17 00:00:00 2001
From: Duke Leto <duke@leto.net>
Date: Mon, 22 Feb 2021 04:44:57 -0500
Subject: [PATCH] Remove unused partition check code

This code is unused and was disabled in BTC core and then deleted,
since it didn't work correctly: https://github.com/bitcoin/bitcoin/pull/8275
---
 src/main.cpp | 73 +++-------------------------------------------------
 src/main.h   |  3 +--
 2 files changed, 5 insertions(+), 71 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 0d581b828..a3322b03b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3043,77 +3043,12 @@ void ThreadScriptCheck() {
     scriptcheckqueue.Thread();
 }
 
-//
-// Called periodically asynchronously; alerts if it smells like
-// we're being fed a bad chain (blocks being generated much
-// too slowly or too quickly).
-//
-void PartitionCheck(bool (*initialDownloadCheck)(), CCriticalSection& cs, const CBlockIndex *const &bestHeader,
-                    int64_t nPowTargetSpacing)
-{
-    if (bestHeader == NULL || initialDownloadCheck()) return;
 
-    static int64_t lastAlertTime = 0;
-    int64_t now = GetTime();
-    if (lastAlertTime > now-60*60*24) return; // Alert at most once per day
-
-    const int SPAN_HOURS=4;
-    const int SPAN_SECONDS=SPAN_HOURS*60*60;
-    int BLOCKS_EXPECTED = SPAN_SECONDS / nPowTargetSpacing;
-
-    boost::math::poisson_distribution<double> poisson(BLOCKS_EXPECTED);
-
-    std::string strWarning;
-    int64_t startTime = GetTime()-SPAN_SECONDS;
-
-    LOCK(cs);
-    const CBlockIndex* i = bestHeader;
-    int nBlocks = 0;
-    while (i->GetBlockTime() >= startTime) {
-        ++nBlocks;
-        i = i->pprev;
-        if (i == NULL) return; // Ran out of chain, we must not be fully synced
-    }
-
-    // How likely is it to find that many by chance?
-    double p = boost::math::pdf(poisson, nBlocks);
-
-    LogPrint("partitioncheck", "%s : Found %d blocks in the last %d hours\n", __func__, nBlocks, SPAN_HOURS);
-    LogPrint("partitioncheck", "%s : likelihood: %g\n", __func__, p);
-
-    // Aim for one false-positive about every fifty years of normal running:
-    const int FIFTY_YEARS = 50*365*24*60*60;
-    double alertThreshold = 1.0 / (FIFTY_YEARS / SPAN_SECONDS);
-
-    if (bestHeader->GetHeight() > BLOCKS_EXPECTED)
-    {
-        if (p <= alertThreshold && nBlocks < BLOCKS_EXPECTED)
-        {
-            // Many fewer blocks than expected: alert!
-            strWarning = strprintf(_("WARNING: check your network connection, %d blocks received in the last %d hours (%d expected)"),
-                                nBlocks, SPAN_HOURS, BLOCKS_EXPECTED);
-        }
-        else if (p <= alertThreshold && nBlocks > BLOCKS_EXPECTED)
-        {
-            // Many more blocks than expected: alert!
-            strWarning = strprintf(_("WARNING: abnormally high number of blocks generated, %d blocks received in the last %d hours (%d expected)"),
-                                nBlocks, SPAN_HOURS, BLOCKS_EXPECTED);
-        }
-    }
-    if (!strWarning.empty())
-    {
-        strMiscWarning = strWarning;
-        CAlert::Notify(strWarning, true);
-        lastAlertTime = now;
-    }
-}
-
-
-static int64_t nTimeVerify = 0;
-static int64_t nTimeConnect = 0;
-static int64_t nTimeIndex = 0;
+static int64_t nTimeVerify    = 0;
+static int64_t nTimeConnect   = 0;
+static int64_t nTimeIndex     = 0;
 static int64_t nTimeCallbacks = 0;
-static int64_t nTimeTotal = 0;
+static int64_t nTimeTotal     = 0;
 bool FindBlockPos(int32_t tmpflag,CValidationState &state, CDiskBlockPos &pos, unsigned int nAddSize, unsigned int nHeight, uint64_t nTime, bool fKnown = false);
 bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBlockIndex *pindexNew, const CDiskBlockPos& pos);
 
diff --git a/src/main.h b/src/main.h
index 62070998d..a624fbd18 100644
--- a/src/main.h
+++ b/src/main.h
@@ -239,8 +239,7 @@ bool ProcessMessages(CNode* pfrom);
 bool SendMessages(CNode* pto, bool fSendTrickle);
 /** Run an instance of the script checking thread */
 void ThreadScriptCheck();
-/** Try to detect Partition (network isolation) attacks against us */
-void PartitionCheck(bool (*initialDownloadCheck)(), CCriticalSection& cs, const CBlockIndex *const &bestHeader, int64_t nPowTargetSpacing);
+
 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
 bool IsInitialBlockDownload();
 /** Check if the daemon is in sync, if not, it returns 1 or if due to best header only, the difference in best