fix: infinite-recursion-form-mapping

binding/form_mapping.go

@@ -75,15 +75,25 @@ func (form formSource) TrySet(value reflect.Value, field reflect.StructField, ta
 }
 
 func mappingByPtr(ptr any, setter setter, tag string) error {
-	_, err := mapping(reflect.ValueOf(ptr), emptyField, setter, tag)
+	_, err := mappingWithDepth(reflect.ValueOf(ptr), emptyField, setter, tag, 0)
 	return err
 }
 
 func mapping(value reflect.Value, field reflect.StructField, setter setter, tag string) (bool, error) {
+	return mappingWithDepth(value, field, setter, tag, 0)
+}
+
+const maxMappingDepth = 10
+
+func mappingWithDepth(value reflect.Value, field reflect.StructField, setter setter, tag string, depth int) (bool, error) {
 	if field.Tag.Get(tag) == "-" { // just ignoring this field
 		return false, nil
 	}
 
+	if depth > maxMappingDepth {
+		return false, nil
+	}
+
 	vKind := value.Kind()
 
 	if vKind == reflect.Ptr {
@@ -93,7 +103,8 @@ func mapping(value reflect.Value, field reflect.StructField, setter setter, tag
 			isNew = true
 			vPtr = reflect.New(value.Type().Elem())
 		}
-		isSet, err := mapping(vPtr.Elem(), field, setter, tag)
+
+		isSet, err := mappingWithDepth(vPtr.Elem(), field, setter, tag, depth+1)
 		if err != nil {
 			return false, err
 		}
@@ -122,7 +133,7 @@ func mapping(value reflect.Value, field reflect.StructField, setter setter, tag
 			if sf.PkgPath != "" && !sf.Anonymous { // unexported
 				continue
 			}
-			ok, err := mapping(value.Field(i), sf, setter, tag)
+			ok, err := mappingWithDepth(value.Field(i), sf, setter, tag, depth+1)
 			if err != nil {
 				return false, err
 			}

binding/form_mapping_test.go

@@ -635,3 +635,62 @@ func TestMappingCustomArrayForm(t *testing.T) {
 	expected, _ := convertTo(val)
 	assert.Equal(t, expected, s.FileData)
 }
+
+// Test case for infinite recursion bug fix
+func TestInfiniteRecursionBug(t *testing.T) {
+	type Req struct {
+		Parent *Req `form:"parent"`
+	}
+
+	var s Req
+	err := MapFormWithTag(&s, map[string][]string{}, "form")
+
+	assert.NoError(t, err)
+	assert.Nil(t, s.Parent)
+}
+
+// Test case for the user's specific example from GitHub issue
+func TestInfiniteRecursionUserExample(t *testing.T) {
+	type Req struct {
+		Foo  string `form:"foo"`
+		Bar  string `form:"bar"`
+		Foo1 string `form:"Foo"`
+		Bar1 string `form:"Bar"`
+		Foo2 *Req   `form:"foo2"`
+	}
+
+	var s Req
+
+	formData := map[string][]string{
+		"foo": {"test_foo"},
+		"bar": {"test_bar"},
+	}
+
+	err := MapFormWithTag(&s, formData, "form")
+
+	assert.NoError(t, err)
+	assert.Equal(t, "test_foo", s.Foo)
+	assert.Equal(t, "test_bar", s.Bar)
+}
+
+// Test case for nested self-reference that should work when data is provided
+func TestValidNestedSelfReference(t *testing.T) {
+	type Req struct {
+		Name   string `form:"name"`
+		Parent *Req   `form:"parent"`
+	}
+
+	var s Req
+
+	formData := map[string][]string{
+		"name":   {"child"},
+		"parent": {`{"name": "parent_name"}`},
+	}
+
+	err := MapFormWithTag(&s, formData, "form")
+
+	assert.NoError(t, err)
+	assert.Equal(t, "child", s.Name)
+	assert.NotNil(t, s.Parent)
+	assert.Equal(t, "parent_name", s.Parent.Name)
+}