From ca017841d65b5f9da5eb4e6e3ca66b009bc54fc4 Mon Sep 17 00:00:00 2001
From: Iyassou Shimels <s.iyassou@gmail.com>
Date: Wed, 23 Sep 2020 22:45:22 +0300
Subject: [PATCH] py/objstr: Make bytes(bytes_obj) return bytes_obj.

Calling the bytes constructor on a bytes object returns the original bytes
object.  This saves allocating a new instance, and matches CPython.

Signed-off-by: Iyassou Shimels <s.iyassou@gmail.com>
---
 py/objstr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/py/objstr.c b/py/objstr.c
index a276a255e5..84728e6f2d 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -205,6 +205,10 @@ STATIC mp_obj_t bytes_make_new(const mp_obj_type_t *type_in, size_t n_args, size
         return mp_const_empty_bytes;
     }
 
+    if (mp_obj_is_type(args[0], &mp_type_bytes)) {
+        return args[0];
+    }
+
     if (mp_obj_is_str(args[0])) {
         if (n_args < 2 || n_args > 3) {
             goto wrong_args;