chore: optimise transfer authz to consume less gas for unbounded spen…

…d limits (#3586)

modules/apps/transfer/types/transfer_authorization.go

@@ -7,6 +7,7 @@ import (
 	sdkmath "cosmossdk.io/math"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/authz"
+
 	ibcerrors "github.com/cosmos/ibc-go/v7/internal/errors"
 	channeltypes "github.com/cosmos/ibc-go/v7/modules/core/04-channel/types"
 	host "github.com/cosmos/ibc-go/v7/modules/core/24-host"
@@ -47,7 +48,7 @@ func (a TransferAuthorization) Accept(ctx sdk.Context, msg sdk.Msg) (authz.Accep
 
 		// If the spend limit is set to the MaxUint256 sentinel value, do not subtract the amount from the spend limit.
 		if allocation.SpendLimit.AmountOf(msgTransfer.Token.Denom).Equal(UnboundedSpendLimit()) {
-			return authz.AcceptResponse{Accept: true, Delete: false, Updated: &a}, nil
+			return authz.AcceptResponse{Accept: true, Delete: false, Updated: nil}, nil
 		}
 
 		limitLeft, isNegative := allocation.SpendLimit.SafeSub(msgTransfer.Token)

modules/apps/transfer/types/transfer_authorization_test.go

@@ -93,11 +93,9 @@ func (suite *TypesTestSuite) TestTransferAuthorizationAccept() {
 			func(res authz.AcceptResponse, err error) {
 				suite.Require().NoError(err)
 
-				updatedTransferAuthz, ok := res.Updated.(*types.TransferAuthorization)
-				suite.Require().True(ok)
-
-				remainder := updatedTransferAuthz.Allocations[0].SpendLimit.AmountOf(sdk.DefaultBondDenom)
-				suite.Require().True(types.UnboundedSpendLimit().Equal(remainder))
+				suite.Require().True(res.Accept)
+				suite.Require().False(res.Delete)
+				suite.Require().Nil(res.Updated)
 			},
 		},
 		{