[Bug]: omitzero does not work with Slice

[AnalogJ]

What happened?

omitzero should correctly ignore empty slices, instead validation continues.

Looks related to this switch case for hasZero - https://github.com/go-playground/validator/blob/master/baked_in.go#L1796
It incorrectly treats nil as the zero case for slices.
Forked the code to experiment with that case, couldn't fix the issue. Looks like omitempty is special in some way.

Version

v10.26.0

Example Code

omitempty

type MyType struct {
	//OrgId   string   `validate:"required"`
	MySlice []string `validate:"omitempty,min=1,dive,uri"`
}

func (req *MyType) Validate() error {
	validate := validator.New(validator.WithRequiredStructEnabled())
	return validate.Struct(req)
}

func main() {
	myInstance1 := &MyType{
		MySlice: nil,
	}
	log.Printf("isValid: %v", myInstance1.Validate())
    // isValid: <nil>

	myInstance2 := &MyType{
		MySlice: []string{},
	}
	log.Printf("isValid: %v", myInstance2.Validate())
    // isValid: Key: 'MyType.MySlice' Error:Field validation for 'MySlice' failed on the 'min' tag
}

omitzero -- which should handle empty slice correctly

type MyType struct {
	//OrgId   string   `validate:"required"`
	MySlice []string `validate:"omitzero,min=1,dive,uri"`
}

func (req *MyType) Validate() error {
	validate := validator.New(validator.WithRequiredStructEnabled())
	return validate.Struct(req)
}

func main() {
	myInstance1 := &MyType{
		MySlice: nil,
	}
	log.Printf("isValid: %v", myInstance1.Validate())
    //isValid: <nil>

	myInstance2 := &MyType{
		MySlice: []string{},
	}
	log.Printf("isValid: %v", myInstance2.Validate())
    //isValid: Key: 'MyType.MySlice' Error:Field validation for 'MySlice' failed on the 'min' tag
}

[JunaidIslam2105]

I think the same issue is with maps as well.

type OmitEmptyExample struct {
	Data map[string]string `validate:"omitempty,min=2"`
}

type OmitZeroExample struct {
	Data map[string]string `validate:"omitzero,min=2"`
}

func main() {
	validate := validator.New()

	test1OmitEmpty := OmitEmptyExample{Data: map[string]string{}}
	test1OmitZero := OmitZeroExample{Data: map[string]string{}}

	fmt.Println("\nTest 1 (empty maps):")
	fmt.Println("omitempty:", validate.Struct(test1OmitEmpty)) // Error (min=2) as expected
	fmt.Println("omitzero:", validate.Struct(test1OmitZero))   // Error but expected no error due to omitzero
}

I think the issue is with this part of the code in baked_in.go

case reflect.Slice, reflect.Map, reflect.Ptr, reflect.Interface, reflect.Chan, reflect.Func:
		return !field.IsNil()

as @AnalogJ pointed out. I tried a fix by explicitly checking if the length is greater than 0 incase of a slice or map and it seems to work. I will open a PR for the changes to be reviewed.