From 27ee4d64f270a24fcd3526562436ebcb2059da4f Mon Sep 17 00:00:00 2001
From: Eirik Ogilvie-Wigley <eirik@z.cash>
Date: Fri, 2 Aug 2019 19:35:53 -0600
Subject: [PATCH] Fix integer truncation in Blossom halving calculation

---
 src/main.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 970dbe052..fbdbf980e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1770,8 +1770,15 @@ CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
     int halvings;
     if (blossomActive) {
         int blossomActivationHeight = consensusParams.vUpgrades[Consensus::UPGRADE_BLOSSOM].nActivationHeight;
-        halvings = (blossomActivationHeight - consensusParams.SubsidySlowStartShift()) / consensusParams.nPreBlossomSubsidyHalvingInterval 
-            + (nHeight - blossomActivationHeight) / consensusParams.nPostBlossomSubsidyHalvingInterval;
+        // // Ideally we would say:
+        // halvings = (blossomActivationHeight - consensusParams.SubsidySlowStartShift()) / consensusParams.nPreBlossomSubsidyHalvingInterval 
+        //     + (nHeight - blossomActivationHeight) / consensusParams.nPostBlossomSubsidyHalvingInterval;
+        // But, (blossomActivationHeight - consensusParams.SubsidySlowStartShift()) / consensusParams.nPreBlossomSubsidyHalvingInterval
+        // needs to be a treated rational number or this does not work.
+        // Define scaledHalvings := halvings * consensusParams.nPreBlossomSubsidyHalvingInterval;
+        int scaledHalvings = (blossomActivationHeight - consensusParams.SubsidySlowStartShift())
+            + (nHeight - blossomActivationHeight) / Consensus::BLOSSOM_POW_TARGET_SPACING_RATIO;
+        halvings = scaledHalvings / consensusParams.nPreBlossomSubsidyHalvingInterval;
     } else {
         halvings = (nHeight - consensusParams.SubsidySlowStartShift()) / consensusParams.nPreBlossomSubsidyHalvingInterval;
     }