From 065a5ab8fb89b6f082a8361b860b48c00f21c301 Mon Sep 17 00:00:00 2001
From: Jeremy Hylton <jeremy@alum.mit.edu>
Date: Thu, 19 Sep 2002 22:57:26 +0000
Subject: [PATCH] whichmodule() should skip dummy package entries in
 sys.modules.

This fixes the charming, but unhelpful error message for
>>> pickle.dumps(type.__new__)
Can't pickle <built-in method __new__ of type object at 0x812a440>: it's not the same object as datetime.math.__new__

Bugfix candidate.
---
 Lib/pickle.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Lib/pickle.py b/Lib/pickle.py
index 4bc54ec5f9..d4085cfbc0 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -626,6 +626,8 @@ def whichmodule(cls, clsname):
         return classmap[cls]
 
     for name, module in sys.modules.items():
+        if module is None: 
+            continue # skip dummy package entries
         if name != '__main__' and \
             hasattr(module, clsname) and \
             getattr(module, clsname) is cls:
-- 
2.50.0