rpcbinding: handle NULL results for structures, fix #3581

Signed-off-by: Roman Khimov <roman@nspcc.ru>

cli/smartcontract/testdata/rpcbindings/notifications/rpcbindings_extended.out

@@ -186,10 +186,15 @@ func (c *Contract) UnexportedFieldUnsigned() (*transaction.Transaction, error) {
 }
 
 // itemToCrazyStruct converts stack item into *CrazyStruct.
+// NULL item is returned as nil pointer without error.
 func itemToCrazyStruct(item stackitem.Item, err error) (*CrazyStruct, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(CrazyStruct)
 	err = res.FromStackItem(item)
 	return res, err
@@ -226,10 +231,15 @@ func (res *CrazyStruct) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToSimpleStruct converts stack item into *SimpleStruct.
+// NULL item is returned as nil pointer without error.
 func itemToSimpleStruct(item stackitem.Item, err error) (*SimpleStruct, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(SimpleStruct)
 	err = res.FromStackItem(item)
 	return res, err

cli/smartcontract/testdata/rpcbindings/notifications/rpcbindings_guessed.out

@@ -186,10 +186,15 @@ func (c *Contract) UnexportedFieldUnsigned() (*transaction.Transaction, error) {
 }
 
 // itemToUnnamed converts stack item into *Unnamed.
+// NULL item is returned as nil pointer without error.
 func itemToUnnamed(item stackitem.Item, err error) (*Unnamed, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(Unnamed)
 	err = res.FromStackItem(item)
 	return res, err
@@ -226,10 +231,15 @@ func (res *Unnamed) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToUnnamedX converts stack item into *UnnamedX.
+// NULL item is returned as nil pointer without error.
 func itemToUnnamedX(item stackitem.Item, err error) (*UnnamedX, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(UnnamedX)
 	err = res.FromStackItem(item)
 	return res, err

cli/smartcontract/testdata/rpcbindings/structs/rpcbindings.out

@@ -161,10 +161,15 @@ func (c *ContractReader) Transaction(t *LedgerTransaction) (*LedgerTransaction,
 }
 
 // itemToLedgerBlock converts stack item into *LedgerBlock.
+// NULL item is returned as nil pointer without error.
 func itemToLedgerBlock(item stackitem.Item, err error) (*LedgerBlock, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(LedgerBlock)
 	err = res.FromStackItem(item)
 	return res, err
@@ -289,10 +294,15 @@ func (res *LedgerBlock) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToLedgerTransaction converts stack item into *LedgerTransaction.
+// NULL item is returned as nil pointer without error.
 func itemToLedgerTransaction(item stackitem.Item, err error) (*LedgerTransaction, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(LedgerTransaction)
 	err = res.FromStackItem(item)
 	return res, err
@@ -385,10 +395,15 @@ func (res *LedgerTransaction) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementABI converts stack item into *ManagementABI.
+// NULL item is returned as nil pointer without error.
 func itemToManagementABI(item stackitem.Item, err error) (*ManagementABI, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementABI)
 	err = res.FromStackItem(item)
 	return res, err
@@ -451,10 +466,15 @@ func (res *ManagementABI) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementContract converts stack item into *ManagementContract.
+// NULL item is returned as nil pointer without error.
 func itemToManagementContract(item stackitem.Item, err error) (*ManagementContract, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementContract)
 	err = res.FromStackItem(item)
 	return res, err
@@ -519,10 +539,15 @@ func (res *ManagementContract) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementEvent converts stack item into *ManagementEvent.
+// NULL item is returned as nil pointer without error.
 func itemToManagementEvent(item stackitem.Item, err error) (*ManagementEvent, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementEvent)
 	err = res.FromStackItem(item)
 	return res, err
@@ -581,10 +606,15 @@ func (res *ManagementEvent) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementGroup converts stack item into *ManagementGroup.
+// NULL item is returned as nil pointer without error.
 func itemToManagementGroup(item stackitem.Item, err error) (*ManagementGroup, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementGroup)
 	err = res.FromStackItem(item)
 	return res, err
@@ -631,10 +661,15 @@ func (res *ManagementGroup) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementManifest converts stack item into *ManagementManifest.
+// NULL item is returned as nil pointer without error.
 func itemToManagementManifest(item stackitem.Item, err error) (*ManagementManifest, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementManifest)
 	err = res.FromStackItem(item)
 	return res, err
@@ -823,10 +858,15 @@ func (res *ManagementManifest) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementMethod converts stack item into *ManagementMethod.
+// NULL item is returned as nil pointer without error.
 func itemToManagementMethod(item stackitem.Item, err error) (*ManagementMethod, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementMethod)
 	err = res.FromStackItem(item)
 	return res, err
@@ -903,10 +943,15 @@ func (res *ManagementMethod) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementParameter converts stack item into *ManagementParameter.
+// NULL item is returned as nil pointer without error.
 func itemToManagementParameter(item stackitem.Item, err error) (*ManagementParameter, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementParameter)
 	err = res.FromStackItem(item)
 	return res, err
@@ -952,10 +997,15 @@ func (res *ManagementParameter) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementPermission converts stack item into *ManagementPermission.
+// NULL item is returned as nil pointer without error.
 func itemToManagementPermission(item stackitem.Item, err error) (*ManagementPermission, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementPermission)
 	err = res.FromStackItem(item)
 	return res, err
@@ -1024,10 +1074,15 @@ func (res *ManagementPermission) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToStructsInternal converts stack item into *StructsInternal.
+// NULL item is returned as nil pointer without error.
 func itemToStructsInternal(item stackitem.Item, err error) (*StructsInternal, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(StructsInternal)
 	err = res.FromStackItem(item)
 	return res, err

cli/smartcontract/testdata/rpcbindings/structs/rpcbindings_dynamic_hash.out

@@ -157,10 +157,15 @@ func (c *ContractReader) Transaction(t *LedgerTransaction) (*LedgerTransaction,
 }
 
 // itemToLedgerBlock converts stack item into *LedgerBlock.
+// NULL item is returned as nil pointer without error.
 func itemToLedgerBlock(item stackitem.Item, err error) (*LedgerBlock, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(LedgerBlock)
 	err = res.FromStackItem(item)
 	return res, err
@@ -285,10 +290,15 @@ func (res *LedgerBlock) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToLedgerTransaction converts stack item into *LedgerTransaction.
+// NULL item is returned as nil pointer without error.
 func itemToLedgerTransaction(item stackitem.Item, err error) (*LedgerTransaction, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(LedgerTransaction)
 	err = res.FromStackItem(item)
 	return res, err
@@ -381,10 +391,15 @@ func (res *LedgerTransaction) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementABI converts stack item into *ManagementABI.
+// NULL item is returned as nil pointer without error.
 func itemToManagementABI(item stackitem.Item, err error) (*ManagementABI, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementABI)
 	err = res.FromStackItem(item)
 	return res, err
@@ -447,10 +462,15 @@ func (res *ManagementABI) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementContract converts stack item into *ManagementContract.
+// NULL item is returned as nil pointer without error.
 func itemToManagementContract(item stackitem.Item, err error) (*ManagementContract, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementContract)
 	err = res.FromStackItem(item)
 	return res, err
@@ -515,10 +535,15 @@ func (res *ManagementContract) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementEvent converts stack item into *ManagementEvent.
+// NULL item is returned as nil pointer without error.
 func itemToManagementEvent(item stackitem.Item, err error) (*ManagementEvent, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementEvent)
 	err = res.FromStackItem(item)
 	return res, err
@@ -577,10 +602,15 @@ func (res *ManagementEvent) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementGroup converts stack item into *ManagementGroup.
+// NULL item is returned as nil pointer without error.
 func itemToManagementGroup(item stackitem.Item, err error) (*ManagementGroup, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementGroup)
 	err = res.FromStackItem(item)
 	return res, err
@@ -627,10 +657,15 @@ func (res *ManagementGroup) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementManifest converts stack item into *ManagementManifest.
+// NULL item is returned as nil pointer without error.
 func itemToManagementManifest(item stackitem.Item, err error) (*ManagementManifest, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementManifest)
 	err = res.FromStackItem(item)
 	return res, err
@@ -819,10 +854,15 @@ func (res *ManagementManifest) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementMethod converts stack item into *ManagementMethod.
+// NULL item is returned as nil pointer without error.
 func itemToManagementMethod(item stackitem.Item, err error) (*ManagementMethod, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementMethod)
 	err = res.FromStackItem(item)
 	return res, err
@@ -899,10 +939,15 @@ func (res *ManagementMethod) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementParameter converts stack item into *ManagementParameter.
+// NULL item is returned as nil pointer without error.
 func itemToManagementParameter(item stackitem.Item, err error) (*ManagementParameter, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementParameter)
 	err = res.FromStackItem(item)
 	return res, err
@@ -948,10 +993,15 @@ func (res *ManagementParameter) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToManagementPermission converts stack item into *ManagementPermission.
+// NULL item is returned as nil pointer without error.
 func itemToManagementPermission(item stackitem.Item, err error) (*ManagementPermission, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(ManagementPermission)
 	err = res.FromStackItem(item)
 	return res, err
@@ -1020,10 +1070,15 @@ func (res *ManagementPermission) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToStructsInternal converts stack item into *StructsInternal.
+// NULL item is returned as nil pointer without error.
 func itemToStructsInternal(item stackitem.Item, err error) (*StructsInternal, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(StructsInternal)
 	err = res.FromStackItem(item)
 	return res, err

cli/smartcontract/testdata/rpcbindings/types/rpcbindings.out

@@ -370,10 +370,15 @@ func (c *ContractReader) UnnamedStructsX() (*UnnamedX, error) {
 }
 
 // itemToUnnamed converts stack item into *Unnamed.
+// NULL item is returned as nil pointer without error.
 func itemToUnnamed(item stackitem.Item, err error) (*Unnamed, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(Unnamed)
 	err = res.FromStackItem(item)
 	return res, err
@@ -404,10 +409,15 @@ func (res *Unnamed) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToUnnamedX converts stack item into *UnnamedX.
+// NULL item is returned as nil pointer without error.
 func itemToUnnamedX(item stackitem.Item, err error) (*UnnamedX, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(UnnamedX)
 	err = res.FromStackItem(item)
 	return res, err

cli/smartcontract/testdata/rpcbindings/types/rpcbindings_dynamic_hash.out

@@ -366,10 +366,15 @@ func (c *ContractReader) UnnamedStructsX() (*UnnamedX, error) {
 }
 
 // itemToUnnamed converts stack item into *Unnamed.
+// NULL item is returned as nil pointer without error.
 func itemToUnnamed(item stackitem.Item, err error) (*Unnamed, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(Unnamed)
 	err = res.FromStackItem(item)
 	return res, err
@@ -400,10 +405,15 @@ func (res *Unnamed) FromStackItem(item stackitem.Item) error {
 }
 
 // itemToUnnamedX converts stack item into *UnnamedX.
+// NULL item is returned as nil pointer without error.
 func itemToUnnamedX(item stackitem.Item, err error) (*UnnamedX, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new(UnnamedX)
 	err = res.FromStackItem(item)
 	return res, err

pkg/smartcontract/rpcbinding/binding.go

@@ -239,10 +239,15 @@ func New(actor Actor{{- if not (len .Hash) -}}, hash util.Uint160{{- end -}}) *C
 {{- range $m := .Methods -}}{{template "METHOD" $m }}{{ end -}}
 {{- range $index, $typ := .NamedTypes }}
 // itemTo{{toTypeName $typ.Name}} converts stack item into *{{toTypeName $typ.Name}}.
+// NULL item is returned as nil pointer without error.
 func itemTo{{toTypeName $typ.Name}}(item stackitem.Item, err error) (*{{toTypeName $typ.Name}}, error) {
 	if err != nil {
 		return nil, err
 	}
+	_, null := item.(stackitem.Null)
+	if null {
+		return nil, nil
+	}
 	var res = new({{toTypeName $typ.Name}})
 	err = res.FromStackItem(item)
 	return res, err