Reorder IBC channel callbacks

From: #8404

Thanks: @fedekunze @colin-axner

CHANGELOG.md

@@ -36,6 +36,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+### Improvements
+
+* (x/ibc) [\#8404](https://github.com/cosmos/cosmos-sdk/pull/8404) Reorder IBC `ChanOpenAck` and `ChanOpenConfirm` handler execution to perform core handler first, followed by application callbacks. 
+
 ### Bug Fixes
 
 * (x/bank) [\#8417](https://github.com/cosmos/cosmos-sdk/pull/8417) Validate balances and coin denom metadata on genesis

x/ibc/core/keeper/msg_server.go

@@ -326,15 +326,15 @@ func (k Keeper) ChannelOpenAck(goCtx context.Context, msg *channeltypes.MsgChann
 		return nil, sdkerrors.Wrapf(porttypes.ErrInvalidRoute, "route not found to module: %s", module)
 	}
 
-	if err = cbs.OnChanOpenAck(ctx, msg.PortId, msg.ChannelId, msg.CounterpartyVersion); err != nil {
-		return nil, sdkerrors.Wrap(err, "channel open ack callback failed")
-	}
-
 	_, err = channel.HandleMsgChannelOpenAck(ctx, k.ChannelKeeper, cap, msg)
 	if err != nil {
 		return nil, err
 	}
 
+	if err = cbs.OnChanOpenAck(ctx, msg.PortId, msg.ChannelId, msg.CounterpartyVersion); err != nil {
+		return nil, sdkerrors.Wrap(err, "channel open ack callback failed")
+	}
+
 	return &channeltypes.MsgChannelOpenAckResponse{}, nil
 }
 
@@ -354,15 +354,15 @@ func (k Keeper) ChannelOpenConfirm(goCtx context.Context, msg *channeltypes.MsgC
 		return nil, sdkerrors.Wrapf(porttypes.ErrInvalidRoute, "route not found to module: %s", module)
 	}
 
-	if err = cbs.OnChanOpenConfirm(ctx, msg.PortId, msg.ChannelId); err != nil {
-		return nil, sdkerrors.Wrap(err, "channel open confirm callback failed")
-	}
-
 	_, err = channel.HandleMsgChannelOpenConfirm(ctx, k.ChannelKeeper, cap, msg)
 	if err != nil {
 		return nil, err
 	}
 
+	if err = cbs.OnChanOpenConfirm(ctx, msg.PortId, msg.ChannelId); err != nil {
+		return nil, sdkerrors.Wrap(err, "channel open confirm callback failed")
+	}
+
 	return &channeltypes.MsgChannelOpenConfirmResponse{}, nil
 }