From 24db3297df203ca34877440632ea3d233a7f6717 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Wed, 13 Mar 2019 00:43:54 -0600
Subject: [PATCH 01/12] (testnet) Fall back to hardcoded shielded pool balance
 to avoid reorgs.

---
 src/chainparams.cpp |  6 ++++++
 src/chainparams.h   |  6 ++++++
 src/main.cpp        | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 1303e6681..7b8a5a7c3 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -353,6 +353,12 @@ public:
             715          //   total number of tx / (checkpoint block height / (24 * 24))
         };
 
+        // Hardcoded fallback value for the Sprout shielded value pool balance
+        // for nodes that have not reindexed since the introduction of monitoring
+        // in #2795.
+        nSproutValuePoolCheckpointHeight = 440329;
+        nSproutValuePoolCheckpointBalance = 40000029096803;
+
         // Founders reward script expects a vector of 2-of-3 multisig addresses
         vFoundersRewardAddress = {
             "t2UNzUUx8mWBCRYPRezvA363EYXyEpHokyi", "t2N9PH9Wk9xjqYg9iin1Ua3aekJqfAtE543", "t2NGQjYMQhFndDHguvUw4wZdNdsssA6K7x2", "t2ENg7hHVqqs9JwU5cgjvSbxnT2a9USNfhy",
diff --git a/src/chainparams.h b/src/chainparams.h
index 2649fa9be..90a0712ae 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -70,6 +70,9 @@ public:
     const std::vector<unsigned char>& AlertKey() const { return vAlertPubKey; }
     int GetDefaultPort() const { return nDefaultPort; }
 
+    CAmount SproutValuePoolCheckpointHeight() const { return nSproutValuePoolCheckpointHeight; }
+    CAmount SproutValuePoolCheckpointBalance() const { return nSproutValuePoolCheckpointBalance; }
+
     const CBlock& GenesisBlock() const { return genesis; }
     /** Make miner wait to have peers to avoid wasting work */
     bool MiningRequiresPeers() const { return fMiningRequiresPeers; }
@@ -125,6 +128,9 @@ protected:
     bool fTestnetToBeDeprecatedFieldRPC = false;
     CCheckpointData checkpointData;
     std::vector<std::string> vFoundersRewardAddress;
+
+    CAmount nSproutValuePoolCheckpointHeight = 0;
+    CAmount nSproutValuePoolCheckpointBalance = 0;
 };
 
 /**
diff --git a/src/main.cpp b/src/main.cpp
index e11dcbc3c..2aeb9fcfc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3296,9 +3296,34 @@ CBlockIndex* AddToBlockIndex(const CBlockHeader& block)
     return pindexNew;
 }
 
+void FallbackSproutValuePoolBalance(
+    CBlockIndex *pindex,
+    const CChainParams& chainparams
+)
+{
+    // Check if the height of this block matches the checkpoint
+    if (pindex->nHeight == chainparams.SproutValuePoolCheckpointHeight()) {
+        // Are we monitoring the Sprout pool?
+        if (!pindex->nChainSproutValue) {
+            // Apparently not. Introduce the hardcoded value.
+            pindex->nChainSproutValue = chainparams.SproutValuePoolCheckpointBalance();
+        } else {
+            // Apparently we have been. So, we should expect the current
+            // value to match the hardcoded one.
+            assert(*pindex->nChainSproutValue == chainparams.SproutValuePoolCheckpointBalance());
+            // And we should expect non-none for the delta stored in the block index here,
+            // or the checkpoint is too early.
+            assert(pindex->nSproutValue != boost::none);
+        }
+    }
+}
+
 /** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */
 bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBlockIndex *pindexNew, const CDiskBlockPos& pos)
 {
+    const CChainParams& chainparams = Params();
+    bool this_is_testnet = chainparams.NetworkIDString() == "test";
+
     pindexNew->nTx = block.vtx.size();
     pindexNew->nChainTx = 0;
     CAmount sproutValue = 0;
@@ -3351,6 +3376,13 @@ bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBl
                 pindex->nChainSproutValue = pindex->nSproutValue;
                 pindex->nChainSaplingValue = pindex->nSaplingValue;
             }
+
+            // Fall back to hardcoded Sprout value pool balance if we're on
+            // testnet.
+            if (this_is_testnet) {
+                FallbackSproutValuePoolBalance(pindex, chainparams);
+            }
+
             {
                 LOCK(cs_nBlockSequenceId);
                 pindex->nSequenceId = nBlockSequenceId++;
@@ -4003,6 +4035,8 @@ CBlockIndex * InsertBlockIndex(uint256 hash)
 bool static LoadBlockIndexDB()
 {
     const CChainParams& chainparams = Params();
+    bool this_is_testnet = chainparams.NetworkIDString() == "test";
+
     if (!pblocktree->LoadBlockIndexGuts())
         return false;
 
@@ -4032,6 +4066,7 @@ bool static LoadBlockIndexDB()
                     } else {
                         pindex->nChainSproutValue = boost::none;
                     }
+
                     if (pindex->pprev->nChainSaplingValue) {
                         pindex->nChainSaplingValue = *pindex->pprev->nChainSaplingValue + pindex->nSaplingValue;
                     } else {
@@ -4048,6 +4083,12 @@ bool static LoadBlockIndexDB()
                 pindex->nChainSproutValue = pindex->nSproutValue;
                 pindex->nChainSaplingValue = pindex->nSaplingValue;
             }
+
+            // Fall back to hardcoded Sprout value pool balance if we're on
+            // testnet.
+            if (this_is_testnet) {
+                FallbackSproutValuePoolBalance(pindex, chainparams);
+            }
         }
         // Construct in-memory chain of branch IDs.
         // Relies on invariant: a block that does not activate a network upgrade

From 8a990a7d6441dcfa30933cf0cd5f10d5ca368441 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Wed, 13 Mar 2019 00:54:29 -0600
Subject: [PATCH 02/12] (testnet) Reject blocks that result in turnstile
 violations

---
 src/main.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/main.cpp b/src/main.cpp
index 2aeb9fcfc..26a8517ec 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2451,6 +2451,32 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
         return true;
     }
 
+    // If we're on testnet, reject a block that results in a negative
+    // shielded value pool balance.
+    if (Params().NetworkIDString() == "test") {
+        // Sprout
+        //
+        // We can expect nChainSproutValue to be valid after the hardcoded
+        // height, and this will be enforced on all descendant blocks. If
+        // the node was reindexed then this will be enforced for all blocks.
+        if (pindex->nChainSproutValue) {
+            if (*pindex->nChainSproutValue < 0) {
+                return state.DoS(100, error("ConnectBlock(): turnstile violation in Sprout shielded value pool"),
+                             REJECT_INVALID, "turnstile-violation-sprout-shielded-pool");
+            }
+        }
+
+        // Sapling
+        //
+        // If we've reached ConnectBlock, we have all transactions of
+        // parents and can expect nChainSaplingValue not to be boost::none.
+        assert(pindex->nChainSaplingValue != boost::none);
+        if (*pindex->nChainSaplingValue < 0) {
+            return state.DoS(100, error("ConnectBlock(): turnstile violation in Sapling shielded value pool"),
+                         REJECT_INVALID, "turnstile-violation-sapling-shielded-pool");
+        }
+    }
+
     // Do not allow blocks that contain transactions which 'overwrite' older transactions,
     // unless those are already completely spent.
     BOOST_FOREACH(const CTransaction& tx, block.vtx) {

From bf4de896e7415fa3951faedfb0b1d3ec6203b2a8 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Wed, 13 Mar 2019 01:13:59 -0600
Subject: [PATCH 03/12] (testnet/regtest) Avoid mining transactions that would
 violate the turnstile.

---
 src/miner.cpp | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/src/miner.cpp b/src/miner.cpp
index 5699e4ba5..dc211ebec 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -109,6 +109,10 @@ void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams,
 CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
 {
     const CChainParams& chainparams = Params();
+    bool this_is_testnet_or_regtest =
+        (chainparams.NetworkIDString() == "test") ||
+        (chainparams.NetworkIDString() == "regtest");
+
     // Create new block
     std::unique_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
     if(!pblocktemplate.get())
@@ -250,6 +254,28 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
         TxPriorityCompare comparer(fSortedByFee);
         std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
 
+        // We want to track the value pool, but if the miner gets
+        // invoked on an old block before the hardcoded fallback
+        // is active we don't want to trip up any assertions. So,
+        // we only adhere to the turnstile (as a miner) if we
+        // actually have all of the information necessary to do
+        // so.
+        CAmount sproutValue = 0;
+        CAmount saplingValue = 0;
+        bool monitoring_pool_balances = true;
+        if (this_is_testnet_or_regtest) {
+            if (pindexPrev->nChainSproutValue) {
+                sproutValue = *pindexPrev->nChainSproutValue;
+            } else {
+                monitoring_pool_balances = false;
+            }
+            if (pindexPrev->nChainSaplingValue) {
+                saplingValue = *pindexPrev->nChainSaplingValue;
+            } else {
+                monitoring_pool_balances = false;
+            }
+        }
+
         while (!vecPriority.empty())
         {
             // Take highest priority transaction off the priority queue:
@@ -305,6 +331,26 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
             if (!ContextualCheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, txdata, Params().GetConsensus(), consensusBranchId))
                 continue;
 
+            if (this_is_testnet_or_regtest && monitoring_pool_balances) {
+                // Does this transaction lead to a turnstile violation?
+
+                CAmount sproutValueDummy = sproutValue;
+                CAmount saplingValueDummy = saplingValue;
+
+                sproutValueDummy += -tx.valueBalance;
+
+                for (auto js : tx.vjoinsplit) {
+                    sproutValueDummy += js.vpub_old;
+                    sproutValueDummy -= js.vpub_new;
+                }
+
+                if (sproutValueDummy < 0) continue;
+                if (saplingValueDummy < 0) continue;
+
+                sproutValue = sproutValueDummy;
+                saplingValue = saplingValueDummy;
+            }
+
             UpdateCoins(tx, view, nHeight);
 
             BOOST_FOREACH(const OutputDescription &outDescription, tx.vShieldedOutput) {

From cb6df4b0ccb131ebcd88f1d8aea9e670dea07ba7 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Thu, 14 Mar 2019 14:08:12 -0600
Subject: [PATCH 04/12] Fix tallying for Sprout/Sapling value pools.

---
 src/main.cpp  | 1 -
 src/miner.cpp | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 26a8517ec..3516deff6 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4092,7 +4092,6 @@ bool static LoadBlockIndexDB()
                     } else {
                         pindex->nChainSproutValue = boost::none;
                     }
-
                     if (pindex->pprev->nChainSaplingValue) {
                         pindex->nChainSaplingValue = *pindex->pprev->nChainSaplingValue + pindex->nSaplingValue;
                     } else {
diff --git a/src/miner.cpp b/src/miner.cpp
index dc211ebec..f45582ba2 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -337,7 +337,7 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
                 CAmount sproutValueDummy = sproutValue;
                 CAmount saplingValueDummy = saplingValue;
 
-                sproutValueDummy += -tx.valueBalance;
+                saplingValueDummy += -tx.valueBalance;
 
                 for (auto js : tx.vjoinsplit) {
                     sproutValueDummy += js.vpub_old;

From 2b1252af8046350cbeda213564d600c3b6786896 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Thu, 14 Mar 2019 14:20:51 -0600
Subject: [PATCH 05/12] Consolidate logic to enable turnstile auditing for
 testnet/regtest/mainnet.

---
 src/chainparams.cpp |  5 +++++
 src/chainparams.h   |  2 ++
 src/main.cpp        | 27 ++++++++++++---------------
 src/miner.cpp       | 17 ++++++++++-------
 4 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 7b8a5a7c3..582c7b6f9 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -358,6 +358,7 @@ public:
         // in #2795.
         nSproutValuePoolCheckpointHeight = 440329;
         nSproutValuePoolCheckpointBalance = 40000029096803;
+        fSproutValuePoolCheckpointEnabled = true;
 
         // Founders reward script expects a vector of 2-of-3 multisig addresses
         vFoundersRewardAddress = {
@@ -472,6 +473,10 @@ public:
         // Founders reward script expects a vector of 2-of-3 multisig addresses
         vFoundersRewardAddress = { "t2FwcEhFdNXuFMv1tcYwaBJtYVtMj8b1uTg" };
         assert(vFoundersRewardAddress.size() <= consensus.GetLastFoundersRewardBlockHeight());
+
+        // Enable Sprout shielded value pool checkpointing on
+        // regtest.
+        fSproutValuePoolCheckpointEnabled = true;
     }
 
     void UpdateNetworkUpgradeParameters(Consensus::UpgradeIndex idx, int nActivationHeight)
diff --git a/src/chainparams.h b/src/chainparams.h
index 90a0712ae..c9c1284d3 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -72,6 +72,7 @@ public:
 
     CAmount SproutValuePoolCheckpointHeight() const { return nSproutValuePoolCheckpointHeight; }
     CAmount SproutValuePoolCheckpointBalance() const { return nSproutValuePoolCheckpointBalance; }
+    bool SproutValuePoolCheckpointEnabled() const { return fSproutValuePoolCheckpointEnabled; }
 
     const CBlock& GenesisBlock() const { return genesis; }
     /** Make miner wait to have peers to avoid wasting work */
@@ -131,6 +132,7 @@ protected:
 
     CAmount nSproutValuePoolCheckpointHeight = 0;
     CAmount nSproutValuePoolCheckpointBalance = 0;
+    bool fSproutValuePoolCheckpointEnabled = false;
 };
 
 /**
diff --git a/src/main.cpp b/src/main.cpp
index 3516deff6..40291aab1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2451,9 +2451,8 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
         return true;
     }
 
-    // If we're on testnet, reject a block that results in a negative
-    // shielded value pool balance.
-    if (Params().NetworkIDString() == "test") {
+    // Reject a block that results in a negative shielded value pool balance.
+    if (Params().SproutValuePoolCheckpointEnabled()) {
         // Sprout
         //
         // We can expect nChainSproutValue to be valid after the hardcoded
@@ -3327,6 +3326,12 @@ void FallbackSproutValuePoolBalance(
     const CChainParams& chainparams
 )
 {
+    // We might not want to enable the checkpointing for mainnet
+    // yet.
+    if (!chainparams.SproutValuePoolCheckpointEnabled()) {
+        return;
+    }
+
     // Check if the height of this block matches the checkpoint
     if (pindex->nHeight == chainparams.SproutValuePoolCheckpointHeight()) {
         // Are we monitoring the Sprout pool?
@@ -3348,7 +3353,6 @@ void FallbackSproutValuePoolBalance(
 bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBlockIndex *pindexNew, const CDiskBlockPos& pos)
 {
     const CChainParams& chainparams = Params();
-    bool this_is_testnet = chainparams.NetworkIDString() == "test";
 
     pindexNew->nTx = block.vtx.size();
     pindexNew->nChainTx = 0;
@@ -3403,11 +3407,8 @@ bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBl
                 pindex->nChainSaplingValue = pindex->nSaplingValue;
             }
 
-            // Fall back to hardcoded Sprout value pool balance if we're on
-            // testnet.
-            if (this_is_testnet) {
-                FallbackSproutValuePoolBalance(pindex, chainparams);
-            }
+            // Fall back to hardcoded Sprout value pool balance
+            FallbackSproutValuePoolBalance(pindex, chainparams);
 
             {
                 LOCK(cs_nBlockSequenceId);
@@ -4061,7 +4062,6 @@ CBlockIndex * InsertBlockIndex(uint256 hash)
 bool static LoadBlockIndexDB()
 {
     const CChainParams& chainparams = Params();
-    bool this_is_testnet = chainparams.NetworkIDString() == "test";
 
     if (!pblocktree->LoadBlockIndexGuts())
         return false;
@@ -4109,11 +4109,8 @@ bool static LoadBlockIndexDB()
                 pindex->nChainSaplingValue = pindex->nSaplingValue;
             }
 
-            // Fall back to hardcoded Sprout value pool balance if we're on
-            // testnet.
-            if (this_is_testnet) {
-                FallbackSproutValuePoolBalance(pindex, chainparams);
-            }
+            // Fall back to hardcoded Sprout value pool balance
+            FallbackSproutValuePoolBalance(pindex, chainparams);
         }
         // Construct in-memory chain of branch IDs.
         // Relies on invariant: a block that does not activate a network upgrade
diff --git a/src/miner.cpp b/src/miner.cpp
index f45582ba2..ec5a198ce 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -109,9 +109,6 @@ void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams,
 CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
 {
     const CChainParams& chainparams = Params();
-    bool this_is_testnet_or_regtest =
-        (chainparams.NetworkIDString() == "test") ||
-        (chainparams.NetworkIDString() == "regtest");
 
     // Create new block
     std::unique_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
@@ -263,7 +260,7 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
         CAmount sproutValue = 0;
         CAmount saplingValue = 0;
         bool monitoring_pool_balances = true;
-        if (this_is_testnet_or_regtest) {
+        if (chainparams.SproutValuePoolCheckpointEnabled()) {
             if (pindexPrev->nChainSproutValue) {
                 sproutValue = *pindexPrev->nChainSproutValue;
             } else {
@@ -331,7 +328,7 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
             if (!ContextualCheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, txdata, Params().GetConsensus(), consensusBranchId))
                 continue;
 
-            if (this_is_testnet_or_regtest && monitoring_pool_balances) {
+            if (chainparams.SproutValuePoolCheckpointEnabled() && monitoring_pool_balances) {
                 // Does this transaction lead to a turnstile violation?
 
                 CAmount sproutValueDummy = sproutValue;
@@ -344,8 +341,14 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
                     sproutValueDummy -= js.vpub_new;
                 }
 
-                if (sproutValueDummy < 0) continue;
-                if (saplingValueDummy < 0) continue;
+                if (sproutValueDummy < 0) {
+                    LogPrintf("CreateNewBlock(): tx %s appears to violate Sprout turnstile", tx.GetHash().ToString());
+                    continue;
+                }
+                if (saplingValueDummy < 0) {
+                    LogPrintf("CreateNewBlock(): tx %s appears to violate Sapling turnstile", tx.GetHash().ToString());
+                    continue;
+                }
 
                 sproutValue = sproutValueDummy;
                 saplingValue = saplingValueDummy;

From 831725a6711b6fb950c80bd6b4e3e4b90e5b42ab Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Thu, 14 Mar 2019 15:25:10 -0600
Subject: [PATCH 06/12] Use existing chainparams variable

---
 src/main.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index 40291aab1..2005a74ea 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2452,7 +2452,7 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
     }
 
     // Reject a block that results in a negative shielded value pool balance.
-    if (Params().SproutValuePoolCheckpointEnabled()) {
+    if (chainparams.SproutValuePoolCheckpointEnabled()) {
         // Sprout
         //
         // We can expect nChainSproutValue to be valid after the hardcoded

From ebe2edce9a72450b9b889871c085bf12d8591258 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Thu, 14 Mar 2019 15:25:31 -0600
Subject: [PATCH 07/12] Add newlines to turntile log messages for miner

---
 src/miner.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/miner.cpp b/src/miner.cpp
index ec5a198ce..53e169c61 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -342,11 +342,11 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
                 }
 
                 if (sproutValueDummy < 0) {
-                    LogPrintf("CreateNewBlock(): tx %s appears to violate Sprout turnstile", tx.GetHash().ToString());
+                    LogPrintf("CreateNewBlock(): tx %s appears to violate Sprout turnstile\n", tx.GetHash().ToString());
                     continue;
                 }
                 if (saplingValueDummy < 0) {
-                    LogPrintf("CreateNewBlock(): tx %s appears to violate Sapling turnstile", tx.GetHash().ToString());
+                    LogPrintf("CreateNewBlock(): tx %s appears to violate Sapling turnstile\n", tx.GetHash().ToString());
                     continue;
                 }
 

From 6482b661abe58b287c548debda33a923826867fd Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Thu, 14 Mar 2019 15:39:11 -0600
Subject: [PATCH 08/12] Check blockhash of fallback block for Sprout value pool
 balance

---
 src/chainparams.cpp |  4 ++++
 src/chainparams.h   |  2 ++
 src/main.cpp        | 28 ++++++++++++++++++----------
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 582c7b6f9..5a02f87be 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -359,6 +359,7 @@ public:
         nSproutValuePoolCheckpointHeight = 440329;
         nSproutValuePoolCheckpointBalance = 40000029096803;
         fSproutValuePoolCheckpointEnabled = true;
+        hashSproutValuePoolCheckpointBlock = uint256S("000a95d08ba5dcbabe881fc6471d11807bcca7df5f1795c99f3ec4580db4279b");
 
         // Founders reward script expects a vector of 2-of-3 multisig addresses
         vFoundersRewardAddress = {
@@ -476,7 +477,10 @@ public:
 
         // Enable Sprout shielded value pool checkpointing on
         // regtest.
+        nSproutValuePoolCheckpointHeight = 0;
+        nSproutValuePoolCheckpointBalance = 0;
         fSproutValuePoolCheckpointEnabled = true;
+        hashSproutValuePoolCheckpointBlock = consensus.hashGenesisBlock;
     }
 
     void UpdateNetworkUpgradeParameters(Consensus::UpgradeIndex idx, int nActivationHeight)
diff --git a/src/chainparams.h b/src/chainparams.h
index c9c1284d3..13e374536 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -72,6 +72,7 @@ public:
 
     CAmount SproutValuePoolCheckpointHeight() const { return nSproutValuePoolCheckpointHeight; }
     CAmount SproutValuePoolCheckpointBalance() const { return nSproutValuePoolCheckpointBalance; }
+    uint256 SproutValuePoolCheckpointBlockHash() const { return hashSproutValuePoolCheckpointBlock; }
     bool SproutValuePoolCheckpointEnabled() const { return fSproutValuePoolCheckpointEnabled; }
 
     const CBlock& GenesisBlock() const { return genesis; }
@@ -132,6 +133,7 @@ protected:
 
     CAmount nSproutValuePoolCheckpointHeight = 0;
     CAmount nSproutValuePoolCheckpointBalance = 0;
+    uint256 hashSproutValuePoolCheckpointBlock;
     bool fSproutValuePoolCheckpointEnabled = false;
 };
 
diff --git a/src/main.cpp b/src/main.cpp
index 2005a74ea..ae9e83536 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3334,17 +3334,25 @@ void FallbackSproutValuePoolBalance(
 
     // Check if the height of this block matches the checkpoint
     if (pindex->nHeight == chainparams.SproutValuePoolCheckpointHeight()) {
-        // Are we monitoring the Sprout pool?
-        if (!pindex->nChainSproutValue) {
-            // Apparently not. Introduce the hardcoded value.
-            pindex->nChainSproutValue = chainparams.SproutValuePoolCheckpointBalance();
+        if (pindex->GetBlockHash() == chainparams.SproutValuePoolCheckpointBlockHash()) {
+            // Are we monitoring the Sprout pool?
+            if (!pindex->nChainSproutValue) {
+                // Apparently not. Introduce the hardcoded value so we monitor for
+                // this point onwards (assuming the checkpoint is late enough)
+                pindex->nChainSproutValue = chainparams.SproutValuePoolCheckpointBalance();
+            } else {
+                // Apparently we have been. So, we should expect the current
+                // value to match the hardcoded one.
+                assert(*pindex->nChainSproutValue == chainparams.SproutValuePoolCheckpointBalance());
+                // And we should expect non-none for the delta stored in the block index here,
+                // or the checkpoint is too early.
+                assert(pindex->nSproutValue != boost::none);
+            }
         } else {
-            // Apparently we have been. So, we should expect the current
-            // value to match the hardcoded one.
-            assert(*pindex->nChainSproutValue == chainparams.SproutValuePoolCheckpointBalance());
-            // And we should expect non-none for the delta stored in the block index here,
-            // or the checkpoint is too early.
-            assert(pindex->nSproutValue != boost::none);
+            LogPrintf(
+                "FallbackSproutValuePoolBalance(): fallback block hash is incorrect, we got %s\n",
+                pindex->GetBlockHash().ToString()
+            );
         }
     }
 }

From b5c7e63bcdab317bc36370e1ec3acf699c263fc0 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Mon, 18 Mar 2019 11:32:26 -0600
Subject: [PATCH 09/12] Change SproutValuePoolCheckpointEnabled to
 ZIP209Activated

---
 src/chainparams.cpp | 4 ++--
 src/chainparams.h   | 4 ++--
 src/main.cpp        | 4 ++--
 src/miner.cpp       | 5 ++---
 4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 5a02f87be..8a45521b2 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -358,7 +358,7 @@ public:
         // in #2795.
         nSproutValuePoolCheckpointHeight = 440329;
         nSproutValuePoolCheckpointBalance = 40000029096803;
-        fSproutValuePoolCheckpointEnabled = true;
+        fZIP209Enabled = true;
         hashSproutValuePoolCheckpointBlock = uint256S("000a95d08ba5dcbabe881fc6471d11807bcca7df5f1795c99f3ec4580db4279b");
 
         // Founders reward script expects a vector of 2-of-3 multisig addresses
@@ -479,7 +479,7 @@ public:
         // regtest.
         nSproutValuePoolCheckpointHeight = 0;
         nSproutValuePoolCheckpointBalance = 0;
-        fSproutValuePoolCheckpointEnabled = true;
+        fZIP209Enabled = true;
         hashSproutValuePoolCheckpointBlock = consensus.hashGenesisBlock;
     }
 
diff --git a/src/chainparams.h b/src/chainparams.h
index 13e374536..ce5c1d6a1 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -73,7 +73,7 @@ public:
     CAmount SproutValuePoolCheckpointHeight() const { return nSproutValuePoolCheckpointHeight; }
     CAmount SproutValuePoolCheckpointBalance() const { return nSproutValuePoolCheckpointBalance; }
     uint256 SproutValuePoolCheckpointBlockHash() const { return hashSproutValuePoolCheckpointBlock; }
-    bool SproutValuePoolCheckpointEnabled() const { return fSproutValuePoolCheckpointEnabled; }
+    bool ZIP209Enabled() const { return fZIP209Enabled; }
 
     const CBlock& GenesisBlock() const { return genesis; }
     /** Make miner wait to have peers to avoid wasting work */
@@ -134,7 +134,7 @@ protected:
     CAmount nSproutValuePoolCheckpointHeight = 0;
     CAmount nSproutValuePoolCheckpointBalance = 0;
     uint256 hashSproutValuePoolCheckpointBlock;
-    bool fSproutValuePoolCheckpointEnabled = false;
+    bool fZIP209Enabled = false;
 };
 
 /**
diff --git a/src/main.cpp b/src/main.cpp
index ae9e83536..50687866c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2452,7 +2452,7 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
     }
 
     // Reject a block that results in a negative shielded value pool balance.
-    if (chainparams.SproutValuePoolCheckpointEnabled()) {
+    if (chainparams.ZIP209Enabled()) {
         // Sprout
         //
         // We can expect nChainSproutValue to be valid after the hardcoded
@@ -3328,7 +3328,7 @@ void FallbackSproutValuePoolBalance(
 {
     // We might not want to enable the checkpointing for mainnet
     // yet.
-    if (!chainparams.SproutValuePoolCheckpointEnabled()) {
+    if (!chainparams.ZIP209Enabled()) {
         return;
     }
 
diff --git a/src/miner.cpp b/src/miner.cpp
index 53e169c61..f83acfe49 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -109,7 +109,6 @@ void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams,
 CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
 {
     const CChainParams& chainparams = Params();
-
     // Create new block
     std::unique_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
     if(!pblocktemplate.get())
@@ -260,7 +259,7 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
         CAmount sproutValue = 0;
         CAmount saplingValue = 0;
         bool monitoring_pool_balances = true;
-        if (chainparams.SproutValuePoolCheckpointEnabled()) {
+        if (chainparams.ZIP209Enabled()) {
             if (pindexPrev->nChainSproutValue) {
                 sproutValue = *pindexPrev->nChainSproutValue;
             } else {
@@ -328,7 +327,7 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
             if (!ContextualCheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, txdata, Params().GetConsensus(), consensusBranchId))
                 continue;
 
-            if (chainparams.SproutValuePoolCheckpointEnabled() && monitoring_pool_balances) {
+            if (chainparams.ZIP209Enabled() && monitoring_pool_balances) {
                 // Does this transaction lead to a turnstile violation?
 
                 CAmount sproutValueDummy = sproutValue;

From 30a5d6f520c9661d3b1da9901b71bf235cc9b25e Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Mon, 18 Mar 2019 14:09:32 -0600
Subject: [PATCH 10/12] Only enforce Sapling turnstile if balance values have
 been populated.

---
 src/main.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 50687866c..be82258d2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2469,10 +2469,14 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
         //
         // If we've reached ConnectBlock, we have all transactions of
         // parents and can expect nChainSaplingValue not to be boost::none.
-        assert(pindex->nChainSaplingValue != boost::none);
-        if (*pindex->nChainSaplingValue < 0) {
-            return state.DoS(100, error("ConnectBlock(): turnstile violation in Sapling shielded value pool"),
-                         REJECT_INVALID, "turnstile-violation-sapling-shielded-pool");
+        // However, the miner and mining RPCs may not have populated this
+        // value and will call `TestBlockValidity`. So, we act
+        // conditionally.
+        if (pindex->nChainSaplingValue) {
+            if (*pindex->nChainSaplingValue < 0) {
+                return state.DoS(100, error("ConnectBlock(): turnstile violation in Sapling shielded value pool"),
+                             REJECT_INVALID, "turnstile-violation-sapling-shielded-pool");
+            }
         }
     }
 

From 4e3dca978bb4cdcfffc0e3ad7fa2f187cab00b79 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Tue, 19 Mar 2019 12:44:53 -0600
Subject: [PATCH 11/12] Do not enable ZIP209 on regtest right now.

---
 src/chainparams.cpp | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 8a45521b2..4b1e391c2 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -474,13 +474,6 @@ public:
         // Founders reward script expects a vector of 2-of-3 multisig addresses
         vFoundersRewardAddress = { "t2FwcEhFdNXuFMv1tcYwaBJtYVtMj8b1uTg" };
         assert(vFoundersRewardAddress.size() <= consensus.GetLastFoundersRewardBlockHeight());
-
-        // Enable Sprout shielded value pool checkpointing on
-        // regtest.
-        nSproutValuePoolCheckpointHeight = 0;
-        nSproutValuePoolCheckpointBalance = 0;
-        fZIP209Enabled = true;
-        hashSproutValuePoolCheckpointBlock = consensus.hashGenesisBlock;
     }
 
     void UpdateNetworkUpgradeParameters(Consensus::UpgradeIndex idx, int nActivationHeight)

From 8d0e2befe712754b32b0f0eef54707916b0fa557 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Tue, 19 Mar 2019 12:45:21 -0600
Subject: [PATCH 12/12] (minor) Remove added newline.

---
 src/main.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index be82258d2..d0d8db976 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3365,7 +3365,6 @@ void FallbackSproutValuePoolBalance(
 bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBlockIndex *pindexNew, const CDiskBlockPos& pos)
 {
     const CChainParams& chainparams = Params();
-
     pindexNew->nTx = block.vtx.size();
     pindexNew->nChainTx = 0;
     CAmount sproutValue = 0;