Limit the nesting depth of a tuple passed as the second argument to
isinstance() or issubclass() to the recursion limit of the interpreter.
diff --git a/Misc/NEWS b/Misc/NEWS
index b0693e0..9f27fd7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,10 @@
Core and builtins
-----------------
+- Limit the nested depth of a tuple for the second argument to isinstance()
+ and issubclass() to the recursion limit of the interpreter.
+ Fixes bug #858016 .
+
- Optimized dict iterators, creating separate types for each
and having them reveal their length. Also optimized the
methods: keys(), values(), and items().