Issue 3110: Crash with weakref subclass,
seen after a "import multiprocessing.reduction"
An instance of a weakref subclass can have attributes.
If such a weakref holds the only strong reference to the object,
deleting the weakref will delete the object. In this case,
the callback must not be called, because the ref object is being deleted!
diff --git a/Misc/NEWS b/Misc/NEWS
index cd44835..386f3f5 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
Core and Builtins
-----------------
+- Issue #3100: Corrected a crash on deallocation of a subclassed weakref which
+ holds the last (strong) reference to its referent.
+
- Add future_builtins.ascii().
- Several set methods now accept multiple arguments: update(), union(),