Copy the value from map and slice to avoid the original value being m…

…odified.

internal/convert/converter.go

@@ -553,22 +553,27 @@ func (c Converter) convertStruct(name string, fromVal, toVal reflect.Value) erro
 }
 
 func (c Converter) convertInterface(name string, fromVal, toVal reflect.Value) error {
-	switch fromVal.Kind() {
-	case reflect.Map:
-		if fromVal.IsNil() {
-			toVal.SetZero()
+	if fromVal.IsZero() {
+		toVal.SetZero()
 
-			return nil
-		}
+		return nil
+	}
 
+	// Copy the value from map and slice to avoid the original value being modified.
+	switch fromVal.Kind() {
+	case reflect.Map:
 		toVal.Set(reflect.MakeMapWithSize(fromVal.Type(), fromVal.Len()))
 
 		return c.convertMap(name, fromVal, toVal.Elem())
+	case reflect.Slice:
+		newSlice := reflect.MakeSlice(fromVal.Type(), fromVal.Len(), fromVal.Len())
+		reflect.Copy(newSlice, fromVal)
+		toVal.Set(newSlice)
 	default:
 		toVal.Set(fromVal)
-
-		return nil
 	}
+
+	return nil
 }
 
 func pointer(val reflect.Value) reflect.Value {

internal/convert/converter_test.go

@@ -961,17 +961,21 @@ func TestConverter(t *testing.T) { //nolint:maintidx
 					Value: "value1",
 				},
 				"key2": "value2",
+				"key3": []int{1, 2},
 			},
 			to: pointer(struct {
 				Key1 interface{}
 				Key2 interface{}
+				Key3 interface{}
 			}{}),
 			expected: pointer(struct {
 				Key1 interface{}
 				Key2 interface{}
+				Key3 interface{}
 			}{
 				Key1: "value1",
 				Key2: "value2",
+				Key3: []int{1, 2},
 			}),
 		},
 		{