commit 8cd1dbae32d9303caac3a473d3332f17bc98c921
author Serhiy Storchaka <storchaka@gmail.com> Sat Oct 24 21:14:23 2020 +0300
committer GitHub <noreply@github.com> Sat Oct 24 21:14:23 2020 +0300
tree 883e8288636eb076d168d2ea57b7a406e2a9d429
parent 473db47747bb8bc986d88ad81799bcbd88153ac5

bpo-41052: Fix pickling heap types implemented in C with protocols 0 and 1 (GH-22870)

Lib/copyreg.py

diff --git a/Lib/copyreg.py b/Lib/copyreg.py
index dfc463c..7ab8c12 100644
--- a/Lib/copyreg.py
+++ b/Lib/copyreg.py
@@ -48,6 +48,7 @@ def _reconstructor(cls, base, state):
     return obj
 
 _HEAPTYPE = 1<<9
+_new_type = type(int.__new__)
 
 # Python code for object.__reduce_ex__ for protocols 0 and 1
 
@@ -57,6 +58,9 @@ def _reduce_ex(self, proto):
     for base in cls.__mro__:
         if hasattr(base, '__flags__') and not base.__flags__ & _HEAPTYPE:
             break
+        new = base.__new__
+        if isinstance(new, _new_type) and new.__self__ is base:
+            break
     else:
         base = object # not really reachable
     if base is object: