refactor: new function GetBlockSubsidyPrev for simplification of usage

src/bench/duplicate_inputs.cpp

@@ -38,7 +38,7 @@ static void DuplicateInputs(benchmark::Bench& bench)
     coinbaseTx.vin[0].prevout.SetNull();
     coinbaseTx.vout.resize(1);
     coinbaseTx.vout[0].scriptPubKey = SCRIPT_PUB;
-    coinbaseTx.vout[0].nValue = GetBlockSubsidy(block.nBits, nHeight, chainparams.GetConsensus());
+    coinbaseTx.vout[0].nValue = GetBlockSubsidyInner(block.nBits, nHeight, chainparams.GetConsensus());
     coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0;
 
     naughtyTx.vout.resize(1);

src/governance/classes.cpp

@@ -486,7 +486,7 @@ CAmount CSuperblock::GetPaymentsLimit(int nBlockHeight)
     // min subsidy for high diff networks and vice versa
     int nBits = consensusParams.fPowAllowMinDifficultyBlocks ? UintToArith256(consensusParams.powLimit).GetCompact() : 1;
     // some part of all blocks issued during the cycle goes to superblock, see GetBlockSubsidy
-    CAmount nSuperblockPartOfSubsidy = GetBlockSubsidy(nBits, nBlockHeight - 1, consensusParams, true);
+    CAmount nSuperblockPartOfSubsidy = GetBlockSubsidyInner(nBits, nBlockHeight - 1, consensusParams, true);
     CAmount nPaymentsLimit = nSuperblockPartOfSubsidy * consensusParams.nSuperblockCycle;
     LogPrint(BCLog::GOBJECT, "CSuperblock::GetPaymentsLimit -- Valid superblock height %d, payments max %lld\n", nBlockHeight, nPaymentsLimit);
 

src/index/coinstatsindex.cpp

@@ -107,7 +107,7 @@ CoinStatsIndex::CoinStatsIndex(size_t n_cache_size, bool f_memory, bool f_wipe)
 bool CoinStatsIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex)
 {
     CBlockUndo block_undo;
-    const CAmount block_subsidy{pindex->nHeight > 0 ? GetBlockSubsidy(pindex->pprev->nBits, pindex->pprev->nHeight, Params().GetConsensus()) : Params().GenesisBlock().vtx[0]->GetValueOut()};
+    const CAmount block_subsidy{GetBlockSubsidy(pindex, Params().GetConsensus())};
     m_total_subsidy += block_subsidy;
 
     // Ignore genesis block
@@ -394,7 +394,7 @@ bool CoinStatsIndex::ReverseBlock(const CBlock& block, const CBlockIndex* pindex
     CBlockUndo block_undo;
     std::pair<uint256, DBVal> read_out;
 
-    const CAmount block_subsidy{pindex->nHeight > 0 ? GetBlockSubsidy(pindex->pprev->nBits, pindex->pprev->nHeight, Params().GetConsensus()) : Params().GenesisBlock().vtx[0]->GetValueOut()};
+    const CAmount block_subsidy{GetBlockSubsidy(pindex, Params().GetConsensus())};
     m_total_subsidy -= block_subsidy;
 
     // Ignore genesis block

src/miner.cpp

@@ -190,7 +190,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     coinbaseTx.vout[0].scriptPubKey = scriptPubKeyIn;
 
     // NOTE: unlike in bitcoin, we need to pass PREVIOUS block height here
-    CAmount blockReward = nFees + GetBlockSubsidy(pindexPrev->nBits, pindexPrev->nHeight, Params().GetConsensus());
+    CAmount blockReward = nFees + GetBlockSubsidyInner(pindexPrev->nBits, pindexPrev->nHeight, Params().GetConsensus());
 
     // Compute regular coinbase transaction.
     coinbaseTx.vout[0].nValue = blockReward;

src/rpc/blockchain.cpp

@@ -2386,7 +2386,7 @@ static UniValue getblockstats(const JSONRPCRequest& request)
     ret_all.pushKV("minfeerate", (minfeerate == MAX_MONEY) ? 0 : minfeerate);
     ret_all.pushKV("mintxsize", mintxsize == MaxBlockSize() ? 0 : mintxsize);
     ret_all.pushKV("outs", outputs);
-    ret_all.pushKV("subsidy", pindex->pprev ? GetBlockSubsidy(pindex->pprev->nBits, pindex->pprev->nHeight, Params().GetConsensus()) : 50 * COIN);
+    ret_all.pushKV("subsidy", GetBlockSubsidy(pindex, Params().GetConsensus()));
     ret_all.pushKV("time", pindex->GetBlockTime());
     ret_all.pushKV("total_out", total_out);
     ret_all.pushKV("total_size", total_size);

src/rpc/masternode.cpp

@@ -459,7 +459,7 @@ static UniValue masternode_payments(const JSONRPCRequest& request, const Chainst
 
         std::vector<CTxOut> voutMasternodePayments, voutDummy;
         CMutableTransaction dummyTx;
-        CAmount blockReward = nBlockFees + GetBlockSubsidy(pindex->pprev->nBits, pindex->pprev->nHeight, Params().GetConsensus());
+        CAmount blockReward = nBlockFees + GetBlockSubsidy(pindex, Params().GetConsensus());
         CMasternodePayments::FillBlockPayments(*sporkManager, *governance, dummyTx, pindex->nHeight, blockReward, voutMasternodePayments, voutDummy);
 
         UniValue blockObj(UniValue::VOBJ);

src/test/block_reward_reallocation_tests.cpp

@@ -201,7 +201,7 @@ BOOST_FIXTURE_TEST_CASE(block_reward_reallocation, TestChainBRRBeforeActivationS
         LOCK(cs_main);
         deterministicMNManager->UpdatedBlockTip(::ChainActive().Tip());
         BOOST_ASSERT(deterministicMNManager->GetListAtChainTip().HasMN(tx.GetHash()));
-        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidy(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
+        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidyInner(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
         const auto pblocktemplate = BlockAssembler(*sporkManager, *governance, *m_node.llmq_ctx, *m_node.evodb, ::ChainstateActive(), *m_node.mempool, Params()).CreateNewBlock(coinbasePubKey);
         BOOST_CHECK_EQUAL(pblocktemplate->voutMasternodePayments[0].nValue, masternode_payment);
     }
@@ -212,7 +212,7 @@ BOOST_FIXTURE_TEST_CASE(block_reward_reallocation, TestChainBRRBeforeActivationS
 
     {
         LOCK(cs_main);
-        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidy(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
+        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidyInner(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
         const auto pblocktemplate = BlockAssembler(*sporkManager, *governance, *m_node.llmq_ctx, *m_node.evodb, ::ChainstateActive(), *m_node.mempool, Params()).CreateNewBlock(coinbasePubKey);
         BOOST_CHECK_EQUAL(pblocktemplate->block.vtx[0]->GetValueOut(), 13748571607);
         BOOST_CHECK_EQUAL(pblocktemplate->voutMasternodePayments[0].nValue, masternode_payment);
@@ -227,7 +227,7 @@ BOOST_FIXTURE_TEST_CASE(block_reward_reallocation, TestChainBRRBeforeActivationS
                 CreateAndProcessBlock({}, coinbaseKey);
             }
             LOCK(cs_main);
-            auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidy(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
+            auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidyInner(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
             const auto pblocktemplate = BlockAssembler(*sporkManager, *governance, *m_node.llmq_ctx, *m_node.evodb, ::ChainstateActive(), *m_node.mempool, Params()).CreateNewBlock(coinbasePubKey);
             BOOST_CHECK_EQUAL(pblocktemplate->voutMasternodePayments[0].nValue, masternode_payment);
         }
@@ -236,7 +236,7 @@ BOOST_FIXTURE_TEST_CASE(block_reward_reallocation, TestChainBRRBeforeActivationS
     {
         // Reward split should reach ~60/40 after reallocation is done
         LOCK(cs_main);
-        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidy(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
+        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidyInner(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
         const auto pblocktemplate = BlockAssembler(*sporkManager, *governance, *m_node.llmq_ctx, *m_node.evodb, ::ChainstateActive(), *m_node.mempool, Params()).CreateNewBlock(coinbasePubKey);
         BOOST_CHECK_EQUAL(pblocktemplate->block.vtx[0]->GetValueOut(), 10221599170);
         BOOST_CHECK_EQUAL(pblocktemplate->voutMasternodePayments[0].nValue, masternode_payment);
@@ -250,15 +250,15 @@ BOOST_FIXTURE_TEST_CASE(block_reward_reallocation, TestChainBRRBeforeActivationS
             CreateAndProcessBlock({}, coinbaseKey);
         }
         LOCK(cs_main);
-        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidy(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
+        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidyInner(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
         const auto pblocktemplate = BlockAssembler(*sporkManager, *governance, *m_node.llmq_ctx, *m_node.evodb, ::ChainstateActive(), *m_node.mempool, Params()).CreateNewBlock(coinbasePubKey);
         BOOST_CHECK_EQUAL(pblocktemplate->voutMasternodePayments[0].nValue, masternode_payment);
     }
 
     {
         // Reward split should reach ~60/40 after reallocation is done
         LOCK(cs_main);
-        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidy(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
+        auto masternode_payment = GetMasternodePayment(::ChainActive().Height(), GetBlockSubsidyInner(::ChainActive().Tip()->nBits, ::ChainActive().Height(), consensus_params), 2500);
         const auto pblocktemplate = BlockAssembler(*sporkManager, *governance, *m_node.llmq_ctx, *m_node.evodb, ::ChainstateActive(), *m_node.mempool, Params()).CreateNewBlock(coinbasePubKey);
         BOOST_CHECK_EQUAL(pblocktemplate->block.vtx[0]->GetValueOut(), 9491484944);
         BOOST_CHECK_EQUAL(pblocktemplate->voutMasternodePayments[0].nValue, masternode_payment);

src/test/subsidy_tests.cpp

@@ -22,51 +22,51 @@ BOOST_AUTO_TEST_CASE(block_subsidy_test)
     // details for block 4249 (subsidy returned will be for block 4250)
     nPrevBits = 0x1c4a47c4;
     nPrevHeight = 4249;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 50000000000ULL);
 
     // details for block 4501 (subsidy returned will be for block 4502)
     nPrevBits = 0x1c4a47c4;
     nPrevHeight = 4501;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 5600000000ULL);
 
     // details for block 5464 (subsidy returned will be for block 5465)
     nPrevBits = 0x1c29ec00;
     nPrevHeight = 5464;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 2100000000ULL);
 
     // details for block 5465 (subsidy returned will be for block 5466)
     nPrevBits = 0x1c29ec00;
     nPrevHeight = 5465;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 12200000000ULL);
 
     // details for block 17588 (subsidy returned will be for block 17589)
     nPrevBits = 0x1c08ba34;
     nPrevHeight = 17588;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 6100000000ULL);
 
     // details for block 99999 (subsidy returned will be for block 100000)
     nPrevBits = 0x1b10cf42;
     nPrevHeight = 99999;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 500000000ULL);
 
     // details for block 210239 (subsidy returned will be for block 210240)
     nPrevBits = 0x1b11548e;
     nPrevHeight = 210239;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 500000000ULL);
 
     // 1st subsidy reduction happens here
 
     // details for block 210240 (subsidy returned will be for block 210241)
     nPrevBits = 0x1b10d50b;
     nPrevHeight = 210240;
-    nSubsidy = GetBlockSubsidy(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
+    nSubsidy = GetBlockSubsidyInner(nPrevBits, nPrevHeight, chainParams->GetConsensus(), false);
     BOOST_CHECK_EQUAL(nSubsidy, 464285715ULL);
 }
 

src/validation.cpp

@@ -1113,7 +1113,7 @@ NOTE:   unlike bitcoin we are using PREVIOUS block height here,
         might be a good idea to change this to use prev bits
         but current height to avoid confusion.
 */
-CAmount GetBlockSubsidy(int nPrevBits, int nPrevHeight, const Consensus::Params& consensusParams, bool fSuperblockPartOnly)
+CAmount GetBlockSubsidyInner(int nPrevBits, int nPrevHeight, const Consensus::Params& consensusParams, bool fSuperblockPartOnly)
 {
     double dDiff;
     CAmount nSubsidyBase;
@@ -1163,6 +1163,12 @@ CAmount GetBlockSubsidy(int nPrevBits, int nPrevHeight, const Consensus::Params&
     return fSuperblockPartOnly ? nSuperblockPart : nSubsidy - nSuperblockPart;
 }
 
+CAmount GetBlockSubsidy(const CBlockIndex* const pindex, const Consensus::Params& consensusParams)
+{
+    if (pindex->pprev == nullptr) return Params().GenesisBlock().vtx[0]->GetValueOut();
+    return GetBlockSubsidyInner(pindex->pprev->nBits, pindex->pprev->nHeight, consensusParams);
+}
+
 CAmount GetMasternodePayment(int nHeight, CAmount blockValue, int nReallocActivationHeight)
 {
     CAmount ret = blockValue/5; // start at 20%
@@ -2401,7 +2407,7 @@ bool CChainState::ConnectBlock(const CBlock& block, BlockValidationState& state,
     // DASH : MODIFIED TO CHECK MASTERNODE PAYMENTS AND SUPERBLOCKS
 
     // TODO: resync data (both ways?) and try to reprocess this block later.
-    CAmount blockReward = nFees + GetBlockSubsidy(pindex->pprev->nBits, pindex->pprev->nHeight, m_params.GetConsensus());
+    CAmount blockReward = nFees + GetBlockSubsidy(pindex, m_params.GetConsensus());
     std::string strError = "";
 
     int64_t nTime5_2 = GetTimeMicros(); nTimeSubsidy += nTime5_2 - nTime5_1;

src/validation.h

@@ -206,7 +206,15 @@ void StopScriptCheckWorkerThreads();
 CTransactionRef GetTransaction(const CBlockIndex* const block_index, const CTxMemPool* const mempool, const uint256& hash, const Consensus::Params& consensusParams, uint256& hashBlock);
 
 double ConvertBitsToDouble(unsigned int nBits);
-CAmount GetBlockSubsidy(int nBits, int nHeight, const Consensus::Params& consensusParams, bool fSuperblockPartOnly = false);
+/**
+ * Due to difference in logic, the GetBlockSubsidy() has also different list of
+ * arguments.
+ *
+ * When pindex points to a genesis block GetBlockSubsidy() returns a pre-calculated value.
+ * For other blocks it calls GetBlockSubsidyInner() using nBits and nHeight of a pindex->pprev block.
+ */
+CAmount GetBlockSubsidyInner(int nPrevBits, int nPrevHeight, const Consensus::Params& consensusParams, bool fSuperblockPartOnly = false);
+CAmount GetBlockSubsidy(const CBlockIndex* const pindex, const Consensus::Params& consensusParams);
 CAmount GetMasternodePayment(int nHeight, CAmount blockValue, int nReallocActivationHeight = std::numeric_limits<int>::max() /* not activated */);
 
 /** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */