py/objexcept: Don't convert errno to str in constructor, do it in print.

OSError's are now printed like:

    OSError: [Errno 1] EPERM

but only if the string corresponding to the errno is found.

1 files changed, 3 insertions, 3 deletions

diff --git a/py/moduerrno.c b/py/moduerrno.c
index 0b543a1934..da3869befd 100644
--- a/py/moduerrno.c
+++ b/py/moduerrno.c
@@ -89,12 +89,12 @@ const mp_obj_module_t mp_module_uerrno = {
     .globals = (mp_obj_dict_t*)&mp_module_uerrno_globals,
 };
 
-mp_obj_t mp_errno_to_str(mp_obj_t errno_val) {
+qstr mp_errno_to_str(mp_obj_t errno_val) {
     mp_map_elem_t *elem = mp_map_lookup((mp_map_t*)&errorcode_dict.map, errno_val, MP_MAP_LOOKUP);
     if (elem == NULL) {
-        return errno_val;
+        return MP_QSTR_NULL;
     } else {
-        return elem->value;
+        return MP_OBJ_QSTR_VALUE(elem->value);
     }
 }