fix: should panic when define duplicate field param in required_if (#1468)

## Fixes Or Enhances
fix #1466 

**Make sure that you've checked the boxes below before you submit PR:**
- [x] Tests exist or have been written that cover this particular
change.

@go-playground/validator-maintainers

---------

Co-authored-by: nodivbyzero <[email protected]>

Author: duyquang6

baked_in.go

@@ -1872,6 +1872,15 @@ func requiredIf(fl FieldLevel) bool {
 	if len(params)%2 != 0 {
 		panic(fmt.Sprintf("Bad param number for required_if %s", fl.FieldName()))
 	}
+
+	seen := make(map[string]struct{})
+	for i := 0; i < len(params); i += 2 {
+		if _, ok := seen[params[i]]; ok {
+			panic(fmt.Sprintf("Duplicate param %s for required_if %s", params[i], fl.FieldName()))
+		}
+		seen[params[i]] = struct{}{}
+	}
+
 	for i := 0; i < len(params); i += 2 {
 		if !requireCheckFieldValue(fl, params[i], params[i+1], false) {
 			return true

doc.go

@@ -264,6 +264,7 @@ The field under validation must be present and not empty only if all
 the other specified fields are equal to the value following the specified
 field. For strings ensures value is not "". For slices, maps, pointers,
 interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value.
+Using the same field name multiple times in the parameters will result in a panic at runtime.
 
 	Usage: required_if
 

validator_test.go

@@ -11099,6 +11099,49 @@ func TestRequiredIf(t *testing.T) {
 	_ = validate.Struct(test3)
 }
 
+func TestRequiredIfDuplicateParams(t *testing.T) {
+	validate := New()
+
+	PanicMatches(t, func() {
+		type TestStruct struct {
+			Field1 string `validate:"required_if=Field2 value1 Field2 value2"`
+			Field2 string
+		}
+		test := TestStruct{
+			Field1: "",
+			Field2: "value1",
+		}
+		_ = validate.Struct(test)
+	}, "Duplicate param Field2 for required_if Field1")
+
+	PanicMatches(t, func() {
+		type TestStruct struct {
+			Field1 string `validate:"required_if=Field2 val1 Field3 val2 Field2 val3"`
+			Field2 string
+			Field3 string
+		}
+		test := TestStruct{
+			Field1: "",
+			Field2: "val1",
+			Field3: "val2",
+		}
+		_ = validate.Struct(test)
+	}, "Duplicate param Field2 for required_if Field1")
+
+	type TestStruct struct {
+		Field1 string `validate:"required_if=Field2 val1 Field3 val2"`
+		Field2 string
+		Field3 string
+	}
+	test := TestStruct{
+		Field1: "",
+		Field2: "val1",
+		Field3: "val2",
+	}
+	errs := validate.Struct(test)
+	NotEqual(t, errs, nil)
+}
+
 func TestRequiredUnless(t *testing.T) {
 	type Inner struct {
 		Field *string
@@ -11169,19 +11212,40 @@ func TestRequiredUnless(t *testing.T) {
 	AssertError(t, errs, "Field10", "Field10", "Field10", "Field10", "required_unless")
 	AssertError(t, errs, "Field11", "Field11", "Field11", "Field11", "required_unless")
 
-	defer func() {
-		if r := recover(); r == nil {
-			t.Errorf("test3 should have panicked!")
+	PanicMatches(t, func() {
+		test3 := struct {
+			Inner  *Inner
+			Field1 string `validate:"required_unless=Inner.Field" json:"field_1"`
+		}{
+			Inner: &Inner{Field: &fieldVal},
 		}
-	}()
+		_ = validate.Struct(test3)
+	}, "Bad param number for required_unless Field1")
 
-	test3 := struct {
-		Inner  *Inner
-		Field1 string `validate:"required_unless=Inner.Field" json:"field_1"`
-	}{
-		Inner: &Inner{Field: &fieldVal},
+	type DuplicateStruct struct {
+		Field1 string `validate:"required_unless=Field2 value1 Field2 value2"`
+		Field2 string
 	}
-	_ = validate.Struct(test3)
+	test4 := DuplicateStruct{
+		Field1: "",
+		Field2: "value1",
+	}
+	errs = validate.Struct(test4)
+	Equal(t, errs, nil)
+
+	test5 := DuplicateStruct{
+		Field1: "",
+		Field2: "value2",
+	}
+	errs = validate.Struct(test5)
+	Equal(t, errs, nil)
+
+	test6 := DuplicateStruct{
+		Field1: "",
+		Field2: "value3",
+	}
+	errs = validate.Struct(test6)
+	NotEqual(t, errs, nil)
 }
 
 func TestSkipUnless(t *testing.T) {