py/objtype: Allow mp_instance_cast_to_native_base to take native obj.

And rename it to mp_obj_cast_to_native_base() to indicate this.  This
allows users of this function to easily support native and native-subclass
objects in the same way (by just passing the object through this function).

1 files changed, 8 insertions, 4 deletions

diff --git a/py/objtype.c b/py/objtype.c
index b2c2f58d9..206e80ffc 100644
--- a/py/objtype.c
+++ b/py/objtype.c
@@ -1389,13 +1389,17 @@ STATIC mp_obj_t mp_builtin_isinstance(mp_obj_t object, mp_obj_t classinfo) {
 
 MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_isinstance_obj, mp_builtin_isinstance);
 
-mp_obj_t mp_instance_cast_to_native_base(mp_const_obj_t self_in, mp_const_obj_t native_type) {
+mp_obj_t mp_obj_cast_to_native_base(mp_obj_t self_in, mp_const_obj_t native_type) {
     const mp_obj_type_t *self_type = mp_obj_get_type(self_in);
-    if (!mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(self_type), native_type)) {
+
+    if (MP_OBJ_FROM_PTR(self_type) == native_type) {
+        return self_in;
+    } else if (!mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(self_type), native_type)) {
         return MP_OBJ_NULL;
+    } else {
+        mp_obj_instance_t *self = (mp_obj_instance_t*)MP_OBJ_TO_PTR(self_in);
+        return self->subobj[0];
     }
-    mp_obj_instance_t *self = (mp_obj_instance_t*)MP_OBJ_TO_PTR(self_in);
-    return self->subobj[0];
 }
 
 /******************************************************************************/