#2016 Fix a crash in function call when the **kwargs dictionary is mutated
during the function call setup.

This even gives a slight speedup, probably because tuple allocation
is faster than PyMem_NEW.
diff --git a/Misc/NEWS b/Misc/NEWS
index c9c9b55..571094c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and Builtins
 -----------------
 
+- Issue #2016: Fixed a crash in a corner case where the dictionary of keyword
+  arguments could be modified during the function call setup.
+
 - Removed the ipaddr module.
 
 - Issue #6329: Fixed iteration for memoryview objects (it was being blocked