From b39c6b99091e43988e3c9034cf1e3a7be5a6fb45 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Sun, 8 Dec 2024 10:14:46 +0000
Subject: [PATCH] fix: avoid potential divide-by-zero in H/s stats calculation

---
 src/init.cpp | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/src/init.cpp b/src/init.cpp
index 1abb710513..1b599eaefd 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -848,20 +848,23 @@ static void PeriodicStats(NodeContext& node)
         LogPrintf("%s: GetUTXOStats failed\n", __func__);
     }
 
-    // short version of GetNetworkHashPS(120, -1);
     CBlockIndex *tip = chainman.ActiveChain().Tip();
-    CBlockIndex *pindex = tip;
-    int64_t minTime = pindex->GetBlockTime();
-    int64_t maxTime = minTime;
-    for (int i = 0; i < 120 && pindex->pprev != nullptr; i++) {
-        pindex = pindex->pprev;
-        int64_t time = pindex->GetBlockTime();
-        minTime = std::min(time, minTime);
-        maxTime = std::max(time, maxTime);
-    }
-    arith_uint256 workDiff = tip->nChainWork - pindex->nChainWork;
-    int64_t timeDiff = maxTime - minTime;
-    double nNetworkHashPS = workDiff.getdouble() / timeDiff;
+    double nNetworkHashPS = [&]() {
+        // Short version of GetNetworkHashPS(120, -1);
+        CBlockIndex *pindex = tip;
+        int64_t minTime = pindex->GetBlockTime();
+        int64_t maxTime = minTime;
+        for (int i = 0; i < 120 && pindex->pprev != nullptr; i++) {
+            pindex = pindex->pprev;
+            int64_t time = pindex->GetBlockTime();
+            minTime = std::min(time, minTime);
+            maxTime = std::max(time, maxTime);
+        }
+        if (minTime == maxTime) return 0.0;
+        arith_uint256 workDiff = tip->nChainWork - pindex->nChainWork;
+        int64_t timeDiff = maxTime - minTime;
+        return workDiff.getdouble() / timeDiff;
+    }();
 
     ::g_stats_client->gaugeDouble("network.hashesPerSecond", nNetworkHashPS);
     ::g_stats_client->gaugeDouble("network.terahashesPerSecond", nNetworkHashPS / 1e12);