Fix bug related to intial utxo hash for the decommit values

v0d1ch · v0d1ch · commit 6e132e5757ea · 2024-05-23T13:45:49.000+02:00
diff --git a/hydra-node/src/Hydra/Chain/Direct/Tx.hs b/hydra-node/src/Hydra/Chain/Direct/Tx.hs
@@ -571,7 +571,7 @@ closeTx scriptRegistry vk closing startSlotNo (endSlotNo, utcTime) openThreadOut
         }
 
   (UTxOHash utxoHashBytes, UTxOHash decommitUTxOHashBytes, snapshotNumber, signature) = case closing of
-    CloseWithInitialSnapshot{openUtxoHash} -> (openUtxoHash, mempty, 0, mempty)
+    CloseWithInitialSnapshot{openUtxoHash} -> (openUtxoHash, UTxOHash $ hashUTxO @Tx mempty, 0, mempty)
     CloseWithConfirmedSnapshot{closeUtxoHash, closeUtxoToDecommitHash, snapshotNumber = sn, signatures = s} ->
       (closeUtxoHash, closeUtxoToDecommitHash, toInteger sn, toPlutusSignatures s)
 
diff --git a/hydra-plutus/src/Hydra/Contract/Head.hs b/hydra-plutus/src/Hydra/Contract/Head.hs
@@ -501,9 +501,7 @@ checkFanout utxoHash utxoToDecommitHash contestationDeadline numberOfFanoutOutpu
 
   hasSameUTxOHash =
     traceIfFalse $(errorCode FannedOutUtxoHashNotEqualToClosedUtxoHash) $
-      -- TODO: revisit and make sure hashing the empty list like here produces
-      -- the correct utxo hash when there are no decommits happening.
-      fannedOutUtxoHash == utxoHash -- && decommitUtxoHash == utxoToDecommitHash
+      fannedOutUtxoHash == utxoHash && decommitUtxoHash == utxoToDecommitHash
   fannedOutUtxoHash = hashTxOuts $ take numberOfFanoutOutputs txInfoOutputs
 
   decommitUtxoHash = hashTxOuts $ take numberOfDecommitOutputs $ drop numberOfFanoutOutputs txInfoOutputs

Original file line number	Diff line number	Diff line change
`@@ -571,7 +571,7 @@ closeTx scriptRegistry vk closing startSlotNo (endSlotNo, utcTime) openThreadOut`
`571`	`571`	`}`
`572`	`572`
`573`	`573`	`(UTxOHash utxoHashBytes, UTxOHash decommitUTxOHashBytes, snapshotNumber, signature) = case closing of`
`574`		`- CloseWithInitialSnapshot{openUtxoHash} -> (openUtxoHash, mempty, 0, mempty)`
	`574`	`+ CloseWithInitialSnapshot{openUtxoHash} -> (openUtxoHash, UTxOHash $ hashUTxO @Tx mempty, 0, mempty)`
`575`	`575`	`CloseWithConfirmedSnapshot{closeUtxoHash, closeUtxoToDecommitHash, snapshotNumber = sn, signatures = s} ->`
`576`	`576`	`(closeUtxoHash, closeUtxoToDecommitHash, toInteger sn, toPlutusSignatures s)`
`577`	`577`