smartcontract: accept Parameter in NewParameterFromValue

While it makes little sense, there can be a situation where this function will
get predefined Parameters in some way.

pkg/smartcontract/parameter.go

@@ -303,6 +303,10 @@ func NewParameterFromValue(value interface{}) (Parameter, error) {
 	case uint64:
 		result.Type = IntegerType
 		result.Value = new(big.Int).SetUint64(v)
+	case *Parameter:
+		result = *v
+	case Parameter:
+		result = v
 	case util.Uint160:
 		result.Type = Hash160Type
 	case util.Uint256:
@@ -321,6 +325,11 @@ func NewParameterFromValue(value interface{}) (Parameter, error) {
 		}
 		result.Type = ArrayType
 		result.Value = arr
+	case []Parameter:
+		arr := make([]Parameter, len(v))
+		copy(arr, v)
+		result.Type = ArrayType
+		result.Value = arr
 	case []*keys.PublicKey:
 		return NewParameterFromValue(keys.PublicKeys(v))
 	case keys.PublicKeys:

pkg/smartcontract/parameter_test.go

@@ -616,6 +616,16 @@ func TestParameterFromValue(t *testing.T) {
 			expType: IntegerType,
 			expVal:  big.NewInt(100),
 		},
+		{
+			value:   Parameter{ByteArrayType, []byte{1, 2, 3}},
+			expType: ByteArrayType,
+			expVal:  []byte{1, 2, 3},
+		},
+		{
+			value:   &Parameter{ByteArrayType, []byte{1, 2, 3}},
+			expType: ByteArrayType,
+			expVal:  []byte{1, 2, 3},
+		},
 		{
 			value:   util.Uint160{1, 2, 3},
 			expType: Hash160Type,
@@ -641,6 +651,11 @@ func TestParameterFromValue(t *testing.T) {
 			expType: ArrayType,
 			expVal:  []Parameter{{ByteArrayType, []byte{1, 2, 3}}, {ByteArrayType, []byte{3, 2, 1}}},
 		},
+		{
+			value:   []Parameter{{ByteArrayType, []byte{1, 2, 3}}, {ByteArrayType, []byte{3, 2, 1}}},
+			expType: ArrayType,
+			expVal:  []Parameter{{ByteArrayType, []byte{1, 2, 3}}, {ByteArrayType, []byte{3, 2, 1}}},
+		},
 		{
 			value:   []*keys.PublicKey{pk1.PublicKey(), pk2.PublicKey()},
 			expType: ArrayType,