Fix bug in abigen v2 template

accounts/abi/bind/base.go

@@ -149,10 +149,6 @@ func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend Co
 // returns, a slice of interfaces for anonymous returns and a struct for named
 // returns.
 func (c *BoundContract) Call(opts *CallOpts, results *[]interface{}, method string, params ...interface{}) error {
-	// Don't crash on a lazy user
-	if opts == nil {
-		opts = new(CallOpts)
-	}
 	if results == nil {
 		results = new([]interface{})
 	}
@@ -161,51 +157,64 @@ func (c *BoundContract) Call(opts *CallOpts, results *[]interface{}, method stri
 	if err != nil {
 		return err
 	}
+	output, err := c.call(opts, input)
+	if err != nil {
+		return err
+	}
+
+	if len(*results) == 0 {
+		res, err := c.abi.Unpack(method, output)
+		*results = res
+		return err
+	}
+	res := *results
+	return c.abi.UnpackIntoInterface(res[0], method, output)
+}
+
+func (c *BoundContract) call(opts *CallOpts, input []byte) ([]byte, error) {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(CallOpts)
+	}
 	var (
 		msg    = ethereum.CallMsg{From: opts.From, To: &c.address, Data: input}
 		ctx    = ensureContext(opts.Context)
 		code   []byte
 		output []byte
+		err    error
 	)
 	if opts.Pending {
 		pb, ok := c.caller.(PendingContractCaller)
 		if !ok {
-			return ErrNoPendingState
+			return nil, ErrNoPendingState
 		}
 		output, err = pb.PendingCallContract(ctx, msg)
 		if err != nil {
-			return err
+			return nil, err
 		}
 		if len(output) == 0 {
 			// Make sure we have a contract to operate on, and bail out otherwise.
 			if code, err = pb.PendingCodeAt(ctx, c.address); err != nil {
-				return err
+				return nil, err
 			} else if len(code) == 0 {
-				return ErrNoCode
+				return nil, ErrNoCode
 			}
 		}
 	} else {
 		output, err = c.caller.CallContract(ctx, msg, opts.BlockNumber)
 		if err != nil {
-			return err
+			return nil, err
 		}
 		if len(output) == 0 {
 			// Make sure we have a contract to operate on, and bail out otherwise.
 			if code, err = c.caller.CodeAt(ctx, c.address, opts.BlockNumber); err != nil {
-				return err
+				return nil, err
 			} else if len(code) == 0 {
-				return ErrNoCode
+				return nil, ErrNoCode
 			}
 		}
 	}
-
-	if len(*results) == 0 {
-		res, err := c.abi.Unpack(method, output)
-		*results = res
-		return err
-	}
-	res := *results
-	return c.abi.UnpackIntoInterface(res[0], method, output)
+	return output, nil
 }
 
 // Transact invokes the (paid) contract method with params as input values.
@@ -409,13 +418,16 @@ func (c *BoundContract) transact(opts *TransactOpts, contract *common.Address, i
 // FilterLogs filters contract logs for past blocks, returning the necessary
 // channels to construct a strongly typed bound iterator on top of them.
 func (c *BoundContract) FilterLogs(opts *FilterOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
+	return c.filterLogs(opts, c.abi.Events[name].ID, query...)
+}
+
+func (c *BoundContract) filterLogs(opts *FilterOpts, eventID common.Hash, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
 	// Don't crash on a lazy user
 	if opts == nil {
 		opts = new(FilterOpts)
 	}
 	// Append the event selector to the query parameters and construct the topic set
-	query = append([][]interface{}{{c.abi.Events[name].ID}}, query...)
-
+	query = append([][]interface{}{{eventID}}, query...)
 	topics, err := abi.MakeTopics(query...)
 	if err != nil {
 		return nil, nil, err
@@ -458,12 +470,16 @@ func (c *BoundContract) FilterLogs(opts *FilterOpts, name string, query ...[]int
 // WatchLogs filters subscribes to contract logs for future blocks, returning a
 // subscription object that can be used to tear down the watcher.
 func (c *BoundContract) WatchLogs(opts *WatchOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
+	return c.watchLogs(opts, c.abi.Events[name].ID, query...)
+}
+
+func (c *BoundContract) watchLogs(opts *WatchOpts, eventID common.Hash, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
 	// Don't crash on a lazy user
 	if opts == nil {
 		opts = new(WatchOpts)
 	}
 	// Append the event selector to the query parameters and construct the topic set
-	query = append([][]interface{}{{c.abi.Events[name].ID}}, query...)
+	query = append([][]interface{}{{eventID}}, query...)
 
 	topics, err := abi.MakeTopics(query...)
 	if err != nil {