Fix nil types tmpl (#751)

* add more nil types and fix int types

* readd hash type

* remove convertToNil

Author: ceyonur

accounts/abi/bind/bind.go

@@ -310,7 +310,6 @@ func BindHelper(types []string, abis []string, bytecodes []string, fsigs []map[s
 		"namedtype":     namedType[lang],
 		"capitalise":    capitalise,
 		"decapitalise":  decapitalise,
-		"convertToNil":  convertToNil,
 		"mkList":        mkList,
 	}
 
@@ -646,24 +645,6 @@ func decapitalise(input string) string {
 	return strings.ToLower(goForm[:1]) + goForm[1:]
 }
 
-// convertToNil converts any type to its proper nil form.
-func convertToNil(input abi.Type) string {
-	switch input.T {
-	case abi.IntTy, abi.UintTy:
-		return "big.NewInt(0)"
-	case abi.StringTy:
-		return "\"\""
-	case abi.BoolTy:
-		return "false"
-	case abi.AddressTy:
-		return "common.Address{}"
-	case abi.HashTy:
-		return "common.Hash{}"
-	default:
-		return "nil"
-	}
-}
-
 // structured checks whether a list of ABI data types has enough information to
 // operate through a proper Go struct or if flat returns are needed.
 func structured(args abi.Arguments) bool {

accounts/abi/bind/precompilebind/precompile_contract_template.go

@@ -153,21 +153,22 @@ func Pack{{.Normalized.Name}}(inputStruct {{capitalise .Normalized.Name}}Input)
 {{else if len .Normalized.Inputs | eq 1 }}
 {{$method := .}}
 {{$input := index $method.Normalized.Inputs 0}}
-// Unpack{{capitalise .Normalized.Name}}Input attempts to unpack [input] into the {{bindtype $input.Type $structs}} type argument
+{{$bindedType := bindtype $input.Type $structs}}
+// Unpack{{capitalise .Normalized.Name}}Input attempts to unpack [input] into the {{$bindedType}} type argument
 // assumes that [input] does not include selector (omits first 4 func signature bytes)
-func Unpack{{capitalise .Normalized.Name}}Input(input []byte)({{bindtype $input.Type $structs}}, error) {
+func Unpack{{capitalise .Normalized.Name}}Input(input []byte)({{$bindedType}}, error) {
 res, err := {{$contract.Type}}ABI.UnpackInput("{{$method.Original.Name}}", input)
 if err != nil {
-	return {{convertToNil $input.Type}}, err
+	return *new({{$bindedType}}), err
 }
-unpacked := *abi.ConvertType(res[0], new({{bindtype $input.Type $structs}})).(*{{bindtype $input.Type $structs}})
+unpacked := *abi.ConvertType(res[0], new({{$bindedType}})).(*{{$bindedType}})
 return unpacked, nil
 }
 
-// Pack{{.Normalized.Name}} packs [{{decapitalise $input.Name}}] of type {{bindtype $input.Type $structs}} into the appropriate arguments for {{$method.Original.Name}}.
+// Pack{{.Normalized.Name}} packs [{{decapitalise $input.Name}}] of type {{$bindedType}} into the appropriate arguments for {{$method.Original.Name}}.
 // the packed bytes include selector (first 4 func signature bytes).
 // This function is mostly used for tests.
-func Pack{{$method.Normalized.Name}}( {{decapitalise $input.Name}} {{bindtype $input.Type $structs}},) ([]byte, error) {
+func Pack{{$method.Normalized.Name}}( {{decapitalise $input.Name}} {{$bindedType}},) ([]byte, error) {
 	return {{$contract.Type}}ABI.Pack("{{$method.Original.Name}}", {{decapitalise $input.Name}},)
 }
 {{else}}
@@ -192,9 +193,10 @@ func Pack{{capitalise .Normalized.Name}}Output (outputStruct {{capitalise .Norma
 {{else if len .Normalized.Outputs | eq 1 }}
 {{$method := .}}
 {{$output := index $method.Normalized.Outputs 0}}
-// Pack{{capitalise .Normalized.Name}}Output attempts to pack given {{decapitalise $output.Name}} of type {{bindtype $output.Type $structs}}
+{{$bindedType := bindtype $output.Type $structs}}
+// Pack{{capitalise .Normalized.Name}}Output attempts to pack given {{decapitalise $output.Name}} of type {{$bindedType}}
 // to conform the ABI outputs.
-func Pack{{$method.Normalized.Name}}Output ({{decapitalise $output.Name}} {{bindtype $output.Type $structs}}) ([]byte, error) {
+func Pack{{$method.Normalized.Name}}Output ({{decapitalise $output.Name}} {{$bindedType}}) ([]byte, error) {
 	return {{$contract.Type}}ABI.PackOutput("{{$method.Original.Name}}", {{decapitalise $output.Name}})
 }
 {{end}}