Fix and re-instate Babbage simpleRewards test

`allPoolStakeCert` needed some adjustments after the `UMap` purge in
`cardano-ledger` and had to make sure that we don't re-register already registered staking credentials.
Also, because validations were turned off apparently, `FailedToValidateSlot` was not triggered
but rather we ended up in an invalid state (the associated delegations were dropped in the account state),
thus resulting in a test failure.
With validation, attempting to re-register already registered staking credentials would trigger the
`StakeKeyAlreadyRegisteredDELEG` predicate failure as per the `DELEG` rule.

Author: Lucsanszky

cardano-chain-gen/src/Cardano/Mock/Forging/Tx/Generic.hs

@@ -190,16 +190,14 @@ resolvePool pix st = case pix of
 
 allPoolStakeCert :: EraCertState era => LedgerState (ShelleyBlock p era) mk -> [ShelleyTxCert era]
 allPoolStakeCert st =
-  ShelleyTxCertDelegCert . ShelleyRegCert <$> nub creds
+  ShelleyTxCertDelegCert . ShelleyRegCert <$> notRegisteredCreds
   where
-    poolParms =
-      let certState =
-            lsCertState $
-              esLState $
-                nesEs $
-                  Consensus.shelleyLedgerState st
-       in Map.elems $ Map.mapWithKey stakePoolStateToPoolParams (certState ^. certPStateL . psStakePoolsL)
+    certState =
+      Consensus.shelleyLedgerState st ^. nesEsL . esLStateL . lsCertStateL
+    poolParms = Map.elems $ Map.mapWithKey stakePoolStateToPoolParams (certState ^. certPStateL . psStakePoolsL)
     creds = concatMap getPoolStakeCreds poolParms
+    notRegisteredCreds =
+      filter (`Map.notMember` (certState ^. certDStateL . accountsL . accountsMapL)) $ nub creds
 
 getPoolStakeCreds :: PoolParams -> [StakeCredential]
 getPoolStakeCreds pparams =

cardano-chain-gen/test/Test/Cardano/Db/Mock/Unit/Babbage.hs

@@ -36,8 +36,8 @@ unitTests iom knownMigrations =
         ]
     , testGroup
         "rewards"
-        [ -- test "rewards simple" BabReward.simpleRewards TODO: possible upstream changed in shelley genesis
-          test "rewards with deregistration" BabReward.rewardsDeregistration
+        [ test "rewards simple" BabReward.simpleRewards
+        , test "rewards with deregistration" BabReward.rewardsDeregistration
         , test "rewards with reregistration. Fixed in Babbage." BabReward.rewardsReregistration
         , test "Mir Cert" BabReward.mirReward
         , -- , test "Mir rollback" mirRewardRollback