exclude_with and exclude_without don't work on pointer fields

[Jake-Convictional]

Package version eg. v9, v10:

v10

Issue, Question or Enhancement:

Using the exclude_with or exclude_without tags don't work as expected on pointer fields (e.g. *string).

See the example below, where the validation fails even though the "excluded" fields are never included. Change the types from *string to string and now the validation succeeds.

Code sample, to showcase or reproduce:

type Test1 struct {
	Field1 string
	Field2 *string `validate:"excluded_with=Field1"`
}

type Test2 struct {
	Field1 string
	Field2 *string `validate:"excluded_without=Field1"`
}

func main() {
	v := validator.New()
	fmt.Println(v.Struct(&Test1{Field1: "ok"})) // Fails, even though Field2 is null
	fmt.Println(v.Struct(&Test2{Field1: "ok"})) // Fails, even though Field2 is null
}

https://play.golang.org/p/QTjxLJOSF8W

[Jake-Convictional]

Update: Please ignore this comment, I realized the problem I mentioned below is because of not passing in the callValidationEvenIfNull parameter.

validator/validator_instance.go

Line 162 in f6584a4

func (v *Validate) RegisterValidation(tag string, fn Func, callValidationEvenIfNull ...bool) error {

Original:
Not sure if this is related, but I'm actually finding that every validator on an empty pointer field is failing, except for some predefined ones like omitempty and isdefault.

type Test struct {
	Field *string `validate:"custom"`
}

func main() {
	v := validator.New()
	err := v.RegisterValidation("custom", custom)
	if err != nil {
		panic(err)
	}
	fmt.Println(v.Struct(&Test{})) // Fails, even though the validator returns true
}

func custom(fl validator.FieldLevel) bool {
	return true
}

https://play.golang.org/p/m_3eMFsw5c2