Make redeem flow handlers open

workflows/src/main/kotlin/com/r3/corda/lib/tokens/workflows/flows/evolvable/CreateEvolvableTokensFlowHandler.kt

@@ -27,6 +27,6 @@ class CreateEvolvableTokensFlowHandler(val otherSession: FlowSession) : FlowLogi
         }
 
         // Resolve the creation transaction.
-        return subFlow(ObserverAwareFinalityFlowHandler(otherSession))
+        subFlow(ObserverAwareFinalityFlowHandler(otherSession))
     }
 }

workflows/src/main/kotlin/com/r3/corda/lib/tokens/workflows/flows/evolvable/UpdateEvolvableTokenFlowHandler.kt

@@ -34,6 +34,6 @@ class UpdateEvolvableTokenFlowHandler(val otherSession: FlowSession) : FlowLogic
         }
 
         // Resolve the update transaction.
-        return subFlow(ObserverAwareFinalityFlowHandler(otherSession))
+        subFlow(ObserverAwareFinalityFlowHandler(otherSession))
     }
 }

workflows/src/main/kotlin/com/r3/corda/lib/tokens/workflows/flows/redeem/RedeemTokensFlowHandler.kt

@@ -19,9 +19,9 @@ import net.corda.core.utilities.unwrap
  * [RedeemNonFungibleTokensFlow], [RedeemTokensFlow].
  */
 // Called on Issuer side.
-class RedeemTokensFlowHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
+class RedeemTokensFlowHandler(val otherSession: FlowSession) : FlowLogic<SignedTransaction?>() {
     @Suspendable
-    override fun call() {
+    override fun call(): SignedTransaction? {
         val role = otherSession.receive<TransactionRole>().unwrap { it }
         if (role == TransactionRole.PARTICIPANT) {
             // Synchronise all confidential identities, issuer isn't involved in move transactions, so states holders may
@@ -42,9 +42,9 @@ class RedeemTokensFlowHandler(val otherSession: FlowSession) : FlowLogic<Unit>()
                 })
             }
         }
-        if (!serviceHub.myInfo.isLegalIdentity(otherSession.counterparty)) {
+        return if (!serviceHub.myInfo.isLegalIdentity(otherSession.counterparty)) {
             // Call observer aware finality flow handler.
             subFlow(ObserverAwareFinalityFlowHandler(otherSession))
-        }
+        } else null
     }
 }

workflows/src/main/kotlin/com/r3/corda/lib/tokens/workflows/flows/rpc/RedeemTokens.kt

@@ -33,9 +33,11 @@ constructor(
 }
 
 @InitiatedBy(RedeemFungibleTokens::class)
-class RedeemFungibleTokensHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
+open class RedeemFungibleTokensHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
     @Suspendable
-    override fun call() = subFlow(RedeemTokensFlowHandler(otherSession))
+    override fun call() {
+        subFlow(RedeemTokensFlowHandler(otherSession))
+    }
 }
 
 @StartableByService
@@ -57,9 +59,11 @@ constructor(
 }
 
 @InitiatedBy(RedeemNonFungibleTokens::class)
-class RedeemNonFungibleTokensHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
+open class RedeemNonFungibleTokensHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
     @Suspendable
-    override fun call() = subFlow(RedeemTokensFlowHandler(otherSession))
+    override fun call() {
+        subFlow(RedeemTokensFlowHandler(otherSession))
+    }
 }
 
 /* Confidential flows. */
@@ -91,7 +95,9 @@ constructor(
 }
 
 @InitiatedBy(ConfidentialRedeemFungibleTokens::class)
-class ConfidentialRedeemFungibleTokensHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
+open class ConfidentialRedeemFungibleTokensHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
     @Suspendable
-    override fun call() = subFlow(ConfidentialRedeemFungibleTokensFlowHandler(otherSession))
-}
+    override fun call() {
+        subFlow(ConfidentialRedeemFungibleTokensFlowHandler(otherSession))
+    }
+}

workflows/src/main/kotlin/com/r3/corda/lib/tokens/workflows/internal/flows/finality/ObserverAwareFinalityFlowHandler.kt

@@ -5,20 +5,21 @@ import net.corda.core.flows.FlowLogic
 import net.corda.core.flows.FlowSession
 import net.corda.core.flows.ReceiveFinalityFlow
 import net.corda.core.node.StatesToRecord
+import net.corda.core.transactions.SignedTransaction
 import net.corda.core.utilities.unwrap
 
-class ObserverAwareFinalityFlowHandler(val otherSession: FlowSession) : FlowLogic<Unit>() {
+class ObserverAwareFinalityFlowHandler(val otherSession: FlowSession) : FlowLogic<SignedTransaction?>() {
     @Suspendable
-    override fun call() {
+    override fun call(): SignedTransaction? {
         val role = otherSession.receive<TransactionRole>().unwrap { it }
         val statesToRecord = when (role) {
             TransactionRole.PARTICIPANT -> StatesToRecord.ONLY_RELEVANT
             TransactionRole.OBSERVER -> StatesToRecord.ALL_VISIBLE
         }
         // If states are issued to self, then ReceiveFinalityFlow does not need to be invoked.
-        if (!serviceHub.myInfo.isLegalIdentity(otherSession.counterparty)) {
+        return if (!serviceHub.myInfo.isLegalIdentity(otherSession.counterparty)) {
             subFlow(ReceiveFinalityFlow(otherSideSession = otherSession, statesToRecord = statesToRecord))
-        }
+        } else null
     }
 }