refactor: Retire fixAmendmentMajorityCalc amendment (#5961)

Amendments activated for more than 2 years can be retired. This change retires the fixAmendmentMajorityCalc amendment.

include/xrpl/protocol/SystemParameters.h

@@ -73,14 +73,8 @@ static constexpr std::uint32_t XRP_LEDGER_EARLIEST_SEQ{32570u};
  * used in asserts and tests. */
 static constexpr std::uint32_t XRP_LEDGER_EARLIEST_FEES{562177u};
 
-/** The minimum amount of support an amendment should have.
-
-    @note This value is used by legacy code and will become obsolete
-          once the fixAmendmentMajorityCalc amendment activates.
-*/
-constexpr std::ratio<204, 256> preFixAmendmentMajorityCalcThreshold;
-
-constexpr std::ratio<80, 100> postFixAmendmentMajorityCalcThreshold;
+/** The minimum amount of support an amendment should have. */
+constexpr std::ratio<80, 100> amendmentMajorityCalcThreshold;
 
 /** The minimum amount of time an amendment must hold a majority */
 constexpr std::chrono::seconds const defaultAmendmentMajorityTime = weeks{2};

include/xrpl/protocol/detail/features.macro

@@ -92,7 +92,6 @@ XRPL_FEATURE(CheckCashMakesTrustLine,    Supported::yes, VoteBehavior::DefaultNo
 XRPL_FEATURE(FlowSortStrands,            Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(TicketBatch,                Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(NegativeUNL,                Supported::yes, VoteBehavior::DefaultYes)
-XRPL_FIX    (AmendmentMajorityCalc,      Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(HardenedValidations,        Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(RequireFullyCanonicalSig,   Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(DeletableAccounts,          Supported::yes, VoteBehavior::DefaultYes)
@@ -139,6 +138,7 @@ XRPL_RETIRE(fix1571)
 XRPL_RETIRE(fix1578)
 XRPL_RETIRE(fix1623)
 XRPL_RETIRE(fix1781)
+XRPL_RETIRE(fixAmendmentMajorityCalc)
 XRPL_RETIRE(fixCheckThreading)
 XRPL_RETIRE(fixQualityUpperBound)
 XRPL_RETIRE(fixRmSmallIncreasedQOffers)

src/test/app/AmendmentTable_test.cpp

@@ -545,8 +545,7 @@ public:
 
             for (auto const& [hash, nVotes] : votes)
             {
-                if (rules.enabled(fixAmendmentMajorityCalc) ? nVotes >= i
-                                                            : nVotes > i)
+                if (nVotes >= i)
                 {
                     // We vote yes on this amendment
                     field.push_back(hash);
@@ -982,10 +981,6 @@ public:
     void
     testChangedUNL(FeatureBitset const& feat)
     {
-        // This test doesn't work without fixAmendmentMajorityCalc enabled.
-        if (!feat[fixAmendmentMajorityCalc])
-            return;
-
         testcase("changedUNL");
 
         auto const testAmendment = amendmentId("changedUNL");
@@ -1143,10 +1138,6 @@ public:
     void
     testValidatorFlapping(FeatureBitset const& feat)
     {
-        // This test doesn't work without fixAmendmentMajorityCalc enabled.
-        if (!feat[fixAmendmentMajorityCalc])
-            return;
-
         testcase("validatorFlapping");
 
         // We run a test where a validator flaps on and off every 23 hours
@@ -1289,14 +1280,12 @@ public:
     run() override
     {
         FeatureBitset const all{test::jtx::testable_amendments()};
-        FeatureBitset const fixMajorityCalc{fixAmendmentMajorityCalc};
 
         testConstruct();
         testGet();
         testBadConfig();
         testEnableVeto();
         testHasUnsupported();
-        testFeature(all - fixMajorityCalc);
         testFeature(all);
     }
 };

src/xrpld/app/misc/detail/AmendmentTable.cpp

@@ -316,36 +316,16 @@ class AmendmentSet
 private:
     // How many yes votes each amendment received
     hash_map<uint256, int> votes_;
-    Rules const& rules_;
     // number of trusted validations
     int trustedValidations_ = 0;
     // number of votes needed
     int threshold_ = 0;
 
-    void
-    computeThreshold(int trustedValidations, Rules const& rules)
-    {
-        threshold_ = !rules_.enabled(fixAmendmentMajorityCalc)
-            ? std::max(
-                  1L,
-                  static_cast<long>(
-                      (trustedValidations_ *
-                       preFixAmendmentMajorityCalcThreshold.num) /
-                      preFixAmendmentMajorityCalcThreshold.den))
-            : std::max(
-                  1L,
-                  static_cast<long>(
-                      (trustedValidations_ *
-                       postFixAmendmentMajorityCalcThreshold.num) /
-                      postFixAmendmentMajorityCalcThreshold.den));
-    }
-
 public:
     AmendmentSet(
         Rules const& rules,
         TrustedVotes const& trustedVotes,
         std::lock_guard<std::mutex> const& lock)
-        : rules_(rules)
     {
         // process validations for ledger before flag ledger.
         auto [trustedCount, newVotes] = trustedVotes.getVotes(rules, lock);
@@ -353,7 +333,11 @@ public:
         trustedValidations_ = trustedCount;
         votes_.swap(newVotes);
 
-        computeThreshold(trustedValidations_, rules);
+        threshold_ = std::max(
+            1L,
+            static_cast<long>(
+                (trustedValidations_ * amendmentMajorityCalcThreshold.num) /
+                amendmentMajorityCalcThreshold.den));
     }
 
     bool
@@ -364,13 +348,9 @@ public:
         if (it == votes_.end())
             return false;
 
-        // Before this fix, it was possible for an amendment to activate with a
-        // percentage slightly less than 80% because we compared for "greater
-        // than or equal to" instead of strictly "greater than".
         // One validator is an exception, otherwise it is not possible
         // to gain majority.
-        if (!rules_.enabled(fixAmendmentMajorityCalc) ||
-            trustedValidations_ == 1)
+        if (trustedValidations_ == 1)
             return it->second >= threshold_;
 
         return it->second > threshold_;