From 358575dada69fb37279e26b2e0cf11fc48870548 Mon Sep 17 00:00:00 2001
From: teodanciu <teodora.danciu@tweag.io>
Date: Tue, 13 Aug 2024 21:42:51 +0100
Subject: [PATCH] Adjust drep expiry set on registration

to subtract the added number of dormant epochs from the total
---
 .../Cardano/Ledger/Conway/Rules/GovCert.hs    | 27 +++++++++++++++++-
 .../Cardano/Ledger/Api/State/Imp/QuerySpec.hs | 28 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs
index e3d9a03bbdc..a7374806d88 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs
@@ -53,6 +53,7 @@ import Cardano.Ledger.Credential (Credential)
 import Cardano.Ledger.Crypto (Crypto)
 import Cardano.Ledger.DRep (DRepState (..), drepAnchorL, drepDepositL, drepExpiryL)
 import Cardano.Ledger.Keys (KeyRole (ColdCommitteeRole, DRepRole))
+import qualified Cardano.Ledger.Shelley.HardForks as HF (bootstrapPhase)
 import Cardano.Slotting.Slot (EpochInterval, binOpEpochNo)
 import Control.DeepSeq (NFData)
 import Control.State.Transition.Extended (
@@ -235,7 +236,15 @@ conwayGovCertTransition = do
           { vsDReps =
               Map.insert
                 cred
-                (DRepState (addEpochInterval cgceCurrentEpoch ppDRepActivity) mAnchor ppDRepDeposit)
+                ( DRepState
+                    ( computeDRepExpiryVersioned
+                        cgcePParams
+                        cgceCurrentEpoch
+                        (vState ^. vsNumDormantEpochsL)
+                    )
+                    mAnchor
+                    ppDRepDeposit
+                )
                 vsDReps
           }
     ConwayUnRegDRep cred refund -> do
@@ -274,6 +283,22 @@ conwayGovCertTransition = do
         UpdateCommittee _ _ newMembers _ -> Map.member coldCred newMembers
         _ -> False
 
+computeDRepExpiryVersioned ::
+  ConwayEraPParams era =>
+  PParams era ->
+  -- | Current epoch
+  EpochNo ->
+  -- | The count of the dormant epochs
+  EpochNo ->
+  EpochNo
+computeDRepExpiryVersioned pp currentEpoch numDormantEpochs
+  -- Starting with version 10, we correctly take into account the number of dormant epochs
+  -- when registering a drep
+  | HF.bootstrapPhase (pp ^. ppProtocolVersionL) =
+      addEpochInterval currentEpoch (pp ^. ppDRepActivityL)
+  | otherwise =
+      computeDRepExpiry (pp ^. ppDRepActivityL) currentEpoch numDormantEpochs
+
 computeDRepExpiry ::
   -- | DRepActivity PParam
   EpochInterval ->
diff --git a/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs b/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs
index ffc767651ad..79dc7cc977f 100644
--- a/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs
+++ b/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs
@@ -28,6 +28,7 @@ import Cardano.Ledger.Core
 import Cardano.Ledger.Credential (Credential (KeyHashObj))
 import Cardano.Ledger.DRep
 import Cardano.Ledger.Keys (KeyRole (..))
+import qualified Cardano.Ledger.Shelley.HardForks as HF
 import Cardano.Ledger.Shelley.LedgerState
 import Data.Default (def)
 import Data.Foldable (Foldable (..))
@@ -70,6 +71,33 @@ spec = do
         expectActualDRepExpiry drep $
           addEpochInterval curEpochNo $
             EpochInterval (drepActivity + fromIntegral n)
+
+      it "dRep registered when there are dormant epochs" $ do
+        let drepActivity = 3
+        modifyPParams $ ppDRepActivityL .~ EpochInterval drepActivity
+        let n = 2
+        passNEpochs n
+        expectNumDormantEpochs $ EpochNo (fromIntegral n)
+        (drep, _, _) <- setupSingleDRep 1_000_000
+
+        let expectedExpiry = do
+              epochNo <- getsNES nesELL
+              let tot = addEpochInterval epochNo (EpochInterval drepActivity)
+              pv <- getProtVer
+              pure $
+                if HF.bootstrapPhase pv
+                  then binOpEpochNo (+) tot (fromIntegral n)
+                  else tot
+
+        expectedExpiry >>= expectActualDRepExpiry drep
+
+        nes <- getsNES id
+        void $ submitParameterChange SNothing $ def & ppuMinFeeAL .~ SJust (Coin 3000)
+
+        expectedExpiry >>= expectDRepExpiry drep
+        drepState <- drepStateFromQuery drep nes
+        expectedExpiry >>= shouldBe (drepState ^. drepExpiryL)
+
       it "proposals are made and numDormantEpochs are added" $ do
         curEpochNo <- getsNES nesELL
         let drepActivity = 3