fix(vtransfer): some tweaks for ack handling

golang/cosmos/x/vibc/types/receiver.go

@@ -38,7 +38,7 @@ func NewReceiver(impl ReceiverImpl) Receiver {
 	}
 }
 
-type portMessage struct { // comes from swingset's IBC handler
+type PortMessage struct { // comes from swingset's IBC handler
 	Type              string              `json:"type"` // IBC_METHOD
 	Method            string              `json:"method"`
 	Packet            channeltypes.Packet `json:"packet"`
@@ -94,7 +94,7 @@ func (ir Receiver) Receive(cctx context.Context, jsonRequest string) (jsonReply
 	ctx := sdk.UnwrapSDKContext(cctx)
 	impl := ir.impl
 
-	msg := new(portMessage)
+	msg := new(PortMessage)
 	err = json.Unmarshal([]byte(jsonRequest), &msg)
 	if err != nil {
 		return "", err

golang/cosmos/x/vtransfer/ibc_middleware.go

@@ -160,7 +160,11 @@ func (im IBCMiddleware) WriteAcknowledgement(
 	packet exported.PacketI,
 	ack exported.Acknowledgement,
 ) error {
-	return im.vtransferKeeper.InterceptWriteAcknowledgement(ctx, chanCap, packet, ack)
+	syncAck := im.vtransferKeeper.InterceptWriteAcknowledgement(ctx, chanCap, packet, ack)
+	if syncAck != nil {
+		return im.vtransferKeeper.WriteAcknowledgement(ctx, chanCap, packet, syncAck)
+	}
+	return nil
 }
 
 ///////////////////////////////////

golang/cosmos/x/vtransfer/ibc_middleware_test.go

@@ -21,6 +21,7 @@ import (
 	swingsettesting "github.com/Agoric/agoric-sdk/golang/cosmos/x/swingset/testing"
 	swingsettypes "github.com/Agoric/agoric-sdk/golang/cosmos/x/swingset/types"
 	vibckeeper "github.com/Agoric/agoric-sdk/golang/cosmos/x/vibc/keeper"
+	vibctypes "github.com/Agoric/agoric-sdk/golang/cosmos/x/vibc/types"
 
 	"github.com/cosmos/cosmos-sdk/baseapp"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -356,6 +357,7 @@ func (s *IntegrationTestSuite) TestTransferFromAgdToAgd() {
 		// {"both targets, both hooks", true, true, []byte("?name=alice&peer=bob"), []byte("?what=arbitrary-data&why=to-test-bridge-targets")},
 	}
 
+	ibcReceiverB := vibctypes.NewReceiver(s.GetApp(s.chainB).VtransferKeeper)
 	path := s.NewTransferPath()
 	serial := make(chan struct{}, 1)
 	serial <- struct{}{}
@@ -466,7 +468,16 @@ func (s *IntegrationTestSuite) TestTransferFromAgdToAgd() {
 					// write out a different acknowledgement from the "contract", one block later.
 					s.coordinator.CommitBlock(s.chainB)
 
-					err = s.GetApp(s.chainB).VtransferKeeper.ReceiveWriteAcknowledgement(s.chainB.GetContext(), packet, finalAck)
+					pm := vibctypes.PortMessage{
+						Type:   "IBC_METHOD",
+						Method: "receiveExecuted",
+						Packet: packet,
+						Ack:    finalAck.Acknowledgement(),
+					}
+					jsonRequest, err := json.Marshal(&pm)
+					s.Require().NoError(err)
+
+					_, err = ibcReceiverB.Receive(s.chainB.GetContext(), string(jsonRequest))
 					s.Require().NoError(err)
 
 					s.coordinator.CommitBlock(s.chainB)

golang/cosmos/x/vtransfer/keeper/keeper.go

@@ -127,11 +127,9 @@ func (k Keeper) InterceptOnRecvPacket(ctx sdk.Context, ibcModule porttypes.IBCMo
 		err := sdkerrors.Wrapf(channeltypes.ErrChannelCapabilityNotFound, "could not retrieve channel capability at: %s", capName)
 		return channeltypes.NewErrorAcknowledgement(err)
 	}
+
 	// Give the VM a chance to write (or override) the ack.
-	if err := k.InterceptWriteAcknowledgement(ctx, chanCap, packet, ack); err != nil {
-		return channeltypes.NewErrorAcknowledgement(err)
-	}
-	return nil
+	return k.InterceptWriteAcknowledgement(ctx, chanCap, packet, ack)
 }
 
 // InterceptOnAcknowledgementPacket checks to see if the packet sender is a
@@ -199,20 +197,21 @@ func (k Keeper) InterceptOnTimeoutPacket(
 
 // InterceptWriteAcknowledgement checks to see if the packet's receiver is a
 // targeted account, and if so, delegates to the VM.
-func (k Keeper) InterceptWriteAcknowledgement(ctx sdk.Context, chanCap *capabilitytypes.Capability, packet ibcexported.PacketI, ack ibcexported.Acknowledgement) error {
+func (k Keeper) InterceptWriteAcknowledgement(ctx sdk.Context, chanCap *capabilitytypes.Capability, packet ibcexported.PacketI, ack ibcexported.Acknowledgement) ibcexported.Acknowledgement {
 	// Get the base baseReceiver from the packet, without computing a stripped packet.
 	baseReceiver, err := types.ExtractBaseAddressFromPacket(k.cdc, packet, types.RoleReceiver, nil)
 	if err != nil || !k.targetIsWatched(ctx, baseReceiver) {
 		// We can't parse, or not watching, but that means just to ack directly.
-		return k.WriteAcknowledgement(ctx, chanCap, packet, ack)
+		return ack
 	}
 
 	// Trigger VM with the original packet.
 	if err = k.vibcKeeper.TriggerWriteAcknowledgement(ctx, baseReceiver, packet, ack); err != nil {
 		errAck := channeltypes.NewErrorAcknowledgement(err)
-		return k.WriteAcknowledgement(ctx, chanCap, packet, errAck)
+		return errAck
 	}
 
+	// The VM has taken over the ack, so we return nil to indicate that the ack is async.
 	return nil
 }