Validator not check property is nil

[bearx3f]

I found some issue about validator It's not check the property is nil before try to get it's properties name and here is reproduce code

{
    "$schema": "http://json-schema.org/draft-04/schema",
    "properties": {
        "prop_1": {
            "type": "string"
        },
        "prop_2": {
            "type": "string"
        },
        "child": {
            "type": "object",
            "properties": {
                "child_prop_1": {
                    "type": "string"
                }
            }
        }
    },
    "required": ["prop1"]
}

package restbot_test

import (
	"fmt"
	"testing"

	schema "github.com/lestrrat/go-jsschema"
	"github.com/lestrrat/go-jsschema/validator"
)

type TestSubject struct {
	Prop1 string            `json:"prop_1,omitempty"`
	Prop2 string            `json:"prop_2,omitempty"`
	Child *TestChildSubject `json:"child,omitempty"`
}

type TestChildSubject struct {
	ChildProp1 string `json:"child_prop_1,omitempty"`
}

func Test_Validator(t *testing.T) {
	data := TestSubject{
		Prop1: "aaa",
	}
	schemaFileName := "validate_schema.json"

	s, err := schema.ReadFile(schemaFileName)
	if err != nil {
		t.Fatal(fmt.Errorf("failed to read schema: %s", err))
	}
	v := validator.New(s)
	if err := v.Validate(data); err != nil {
		t.Fatal(fmt.Errorf("failed to validate data: %s", err))
	}
}

And error message

--- FAIL: Test_Validator (0.00s)
	z:\go\src\booboo-bear.com\restbot\validate_test.go:34: 
failed to validate data: validator 0xc04210dec0 
failed: object property 'child' validation 
failed: cannot get property names from this value (Kind: invalid)
FAIL
FAIL	booboo-bear.com/restbot	0.479s
Error: Tests failed.

[bearx3f]

i'm using this code to workaround but i don't how it's affect.

diff --git a/object.go b/object.go
index 274ce1f..7d04086 100644
--- a/object.go
+++ b/object.go
@@ -392,6 +392,8 @@ func (o *ObjectConstraint) Validate(v interface{}) (err error) {
                                out = mv.Call(nil)
                                pval = out[0]
                        }
+               case (pval.Kind() == reflect.Ptr || pval.Kind() == reflect.Interface) && pval.IsNil():
+                       // If we got nil, we're done for
                default:
                        // Everything else, we have *something*
                        propExists = true