Issue #16602: When a weakref's target was part of a long deallocation chain, the object could remain reachable through its weakref even though its refcount had dropped to zero.
Thanks to Eugene Toder for diagnosing and reporting the issue.
diff --git a/Misc/NEWS b/Misc/NEWS
index 3c9f382..5152c03 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
Core and Builtins
-----------------
+- Issue #16602: When a weakref's target was part of a long deallocation
+ chain, the object could remain reachable through its weakref even though
+ its refcount had dropped to zero.
+
- Issue #16416: On Mac OS X, operating system data are now always
encoded/decoded to/from UTF-8/surrogateescape, instead of the locale encoding
(which may be ASCII if no locale environment variable is set), to avoid