rpc, util, consensus: Implement exception handling framework for MRC and fix ValidateMRC to deal with testnet consensus issue

src/gridcoin/mrc.cpp

@@ -279,30 +279,43 @@ bool TrySignMRC(
 }
 } // anonymous namespace
 
-bool GRC::CreateMRC(CBlockIndex* pindex,
+void GRC::CreateMRC(CBlockIndex* pindex,
                     MRC& mrc,
                     CAmount &nReward,
                     CAmount &fee,
                     CWallet* pwallet) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
     const GRC::ResearcherPtr researcher = GRC::Researcher::Get();
 
-    mrc.m_mining_id = researcher->Id();
-
-    if (researcher->Status() == GRC::ResearcherStatus::NO_BEACON) {
-        error("%s: CPID eligible but no active beacon key so MRC cannot be formed.", __func__);
-
-        return false;
+    bool err = true;
+
+    switch (researcher->Status())
+    {
+    case GRC::ResearcherStatus::ACTIVE:
+        // Not an error.
+        err = false;
+        break;
+    case GRC::ResearcherStatus::NO_BEACON:
+        throw MRC_error(strprintf("%s: CPID eligible but no active beacon key so MRC cannot be formed.", __func__));
+    case GRC::ResearcherStatus::INVESTOR:
+        throw MRC_error(strprintf("%s: MRC request cannot be sent while wallet is in investor mode.", __func__));
+    case GRC::ResearcherStatus::NO_PROJECTS:
+        // This is handled as no positive research reward pending below.
+        err = false;
+        break;
+    case GRC::ResearcherStatus::POOL:
+        throw MRC_error(strprintf("%s: MRC request cannot be sent while wallet is in pool mode.", __func__));
     }
+    if (err) assert(false);
+
+    mrc.m_mining_id = researcher->Id();
 
     if (const GRC::CpidOption cpid = mrc.m_mining_id.TryCpid()) {
         mrc.m_research_subsidy = GRC::Tally::GetAccrual(*cpid, pindex->nTime, pindex);
 
         // If no pending research subsidy value exists, bail.
         if (mrc.m_research_subsidy <= 0) {
-            error("%s: No positive research reward pending at time of mrc.", __func__);
-
-            return false;
+            throw MRC_error(strprintf("%s: No positive research reward pending at time of mrc.", __func__));
         } else {
             nReward = mrc.m_research_subsidy;
             mrc.m_magnitude = GRC::Quorum::GetMagnitude(*cpid).Floating();
@@ -326,16 +339,25 @@ bool GRC::CreateMRC(CBlockIndex* pindex,
         // Set the output fee equal to computed (for help with error handling)
         CAmount provided_fee = fee;
         fee = computed_mrc_fee;
-        return error("%s: Invalid fee specified for mrc. The specified fee of %s is not bounded by the "
-                     "minimum calculated fee of %s and the computed research reward of %s.",
-                     __func__,
-                     FormatMoney(provided_fee),
-                     FormatMoney(computed_mrc_fee),
-                     FormatMoney(mrc.m_research_subsidy));
+
+        if (provided_fee < computed_mrc_fee) {
+            throw MRC_error(strprintf("%s: Invalid fee specified for mrc. The specified fee of %s is less than "
+                                      "the minimum calculated fee of %s.",
+                                      __func__,
+                                      FormatMoney(provided_fee),
+                                      FormatMoney(computed_mrc_fee)));
+        } else {
+            throw MRC_error(strprintf("%s: Invalid fee specified for mrc. The specified fee of %s is greater than "
+                                      "the computed research reward of %s.",
+                                      __func__,
+                                      FormatMoney(provided_fee),
+                                      FormatMoney(mrc.m_research_subsidy)));
+
+        }
     }
 
     if (!TrySignMRC(pwallet, pindex, mrc)) {
-        return error("%s: Failed to sign mrc.", __func__);
+        throw MRC_error(strprintf("%s: Failed to sign mrc.", __func__));
     }
 
     LogPrintf(
@@ -345,7 +367,5 @@ bool GRC::CreateMRC(CBlockIndex* pindex,
         FormatMoney(nReward),
         mrc.m_magnitude,
         FormatMoney(mrc.m_research_subsidy));
-
-    return true;
 }
 

src/gridcoin/mrc.h

@@ -18,6 +18,15 @@
 class CPubKey;
 
 namespace GRC {
+class MRC_error : public std::runtime_error
+{
+public:
+    explicit MRC_error(const std::string& str) : std::runtime_error("ERROR: " + str)
+    {
+        LogPrintf("ERROR: %s", str);
+    }
+};
+
 //!
 //! \brief Contains the reward claim context embedded in each generated block.
 //!
@@ -341,7 +350,7 @@ class MRCContractHandler : public IContractHandler
 //! \param pwallet: The wallet object
 //! \return
 //!
-bool CreateMRC(CBlockIndex* pindex, MRC& mrc, CAmount &nReward, CAmount &fee, CWallet* pwallet);
+void CreateMRC(CBlockIndex* pindex, MRC& mrc, CAmount &nReward, CAmount &fee, CWallet* pwallet);
 
 
 } // namespace GRC

src/gridcoin/staking/kernel.cpp

@@ -392,7 +392,7 @@ bool GRC::ReadStakedInput(
     // Get transaction index for the previous transaction
     if (!txdb.ReadTxIndex(prevout_hash, tx_index)) {
         // Previous transaction not in main chain, may occur during initial download
-        return error("%s: tx index not found", __func__);
+        return error("%s: tx index not found for input tx %s", __func__, prevout_hash.GetHex());
     }
 
     const CDiskTxPos pos = tx_index.pos;

src/main.cpp

@@ -4706,13 +4706,32 @@ bool ValidateMRC(const GRC::Contract& contract, const CTransaction& tx)
     const GRC::ResearchAccount& account = GRC::Tally::GetAccount(*cpid);
     const int64_t last_reward_time = account.LastRewardTime();
 
-    const int64_t payment_interval = mrc_time - last_reward_time;
+    const int64_t payment_interval_by_mrc = mrc_time - last_reward_time;
+    const int64_t payment_interval_by_tx_time = tx.nTime - last_reward_time;
 
-    if (payment_interval < reject_payment_interval) {
-        return error("%s: Validation failed: MRC payment interval by tx time, %" PRId64 " sec, is less than 1/2 of the MRC "
+    bool payment_interval_by_mrc_reject = (payment_interval_by_mrc < reject_payment_interval) ? true : false;
+    bool payment_interval_by_tx_time_reject = (payment_interval_by_tx_time < reject_payment_interval) ? true : false;;
+
+    if (!fTestNet && payment_interval_by_mrc_reject) {
+        return error("%s: Validation failed: MRC payment interval by mrc time, %" PRId64 " sec, is less than 1/2 of the MRC "
                      "Zero Payment Interval of %" PRId64 " sec.",
                      __func__,
-                     payment_interval,
+                     payment_interval_by_mrc,
+                     reject_payment_interval);
+    }
+
+    // For testnet, both rejection conditions must be true (i.e. the payment interval by both mrc and tx time is less
+    // than 1/2 of MRCZeroPaymentInterval) for the transaction to be rejected. This difference from mainnet is to
+    // accomodate a post testnet v12 change in this function that originally shifted from tx time to mrc time for MRC
+    // payment interval rejection, after some mrc tests were already done post mandatory, which broke syncing from zero.
+    //
+    // TODO: On the next mandatory align the restriction to mainnet from that point forward.
+    if (fTestNet && payment_interval_by_mrc_reject && payment_interval_by_tx_time_reject) {
+        return error("%s: Validation failed: MRC payment interval on testnet by both mrc time, %" PRId64 " sec, "
+                     "and tx time, %" PRId64 " is less than 1/2 of the MRC Zero Payment Interval of %" PRId64 " sec.",
+                     __func__,
+                     payment_interval_by_mrc,
+                     payment_interval_by_tx_time,
                      reject_payment_interval);
     }
 

src/rpc/blockchain.cpp

@@ -2530,8 +2530,10 @@ UniValue createmrcrequest(const UniValue& params, const bool fHelp) {
     // If the fee is not overridden by the provided fee above (i.e. zero), it will be filled in
     // at the calculated mrc value by CreateMRC. CreateMRC also rechecks the bounds
     // of the provided fee.
-    if (!GRC::CreateMRC(pindex, mrc, reward, fee, pwalletMain)) {
-        throw runtime_error("MRC request creation failed. Please check the log for details.");
+    try {
+        GRC::CreateMRC(pindex, mrc, reward, fee, pwalletMain);
+    } catch (GRC::MRC_error& e) {
+        throw runtime_error(e.what());
     }
 
     if (!dry_run && !force && reward == fee) {

src/test/gridcoin/mrc_tests.cpp

@@ -193,7 +193,7 @@ BOOST_AUTO_TEST_CASE(createmrc_creates_valid_mrcs)
 {
     account.m_accrual = 72;
     GRC::MRC mrc;
-    CAmount reward, fee{0};
+    CAmount reward{0}, fee{0};
     GRC::CreateMRC(pindex->pprev, mrc, reward, fee, wallet);
 
     BOOST_CHECK_EQUAL(reward, 72);
@@ -207,7 +207,7 @@ BOOST_AUTO_TEST_CASE(it_accepts_valid_fees)
 {
     account.m_accrual = 72;
     GRC::MRC mrc;
-    CAmount reward, fee{0};
+    CAmount reward{0}, fee{0};
     GRC::CreateMRC(pindex->pprev, mrc, reward, fee, wallet);
 
     mrc.m_fee = 14;
@@ -239,7 +239,7 @@ BOOST_AUTO_TEST_CASE(it_creates_valid_mrc_claims)
     BOOST_CHECK(CreateRestOfTheBlock(block, pindex->pprev, mrc_map));
 
     GRC::MRC mrc;
-    CAmount reward, fee;
+    CAmount reward{0}, fee{0};
     GRC::CreateMRC(pindex->pprev, mrc, reward, fee, wallet);
     mrc_map[cpid] = {uint256{}, mrc};