Fix segfaults when running test_exceptions with coverage tracing, caused by wrongly defining Exception.__context__ as a T_OBJECT structmember which does not set the member to NULL on None assignment, and generally does not do type checks. This could be used to crash the interpreter by setting any object to __context__. The same applies to __cause__. Also document the PyException_* functions.
diff --git a/Misc/NEWS b/Misc/NEWS
index 894aa71..911e944 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -1,4 +1,5 @@
-+++++++++++ Python News
++++++++++++
+Python News
+++++++++++
(editors: check NEWS.help for information about editing NEWS using ReST.)
@@ -11,6 +12,9 @@
Core and Builtins
-----------------
+- Fix a segfault when running test_exceptions with coverage, caused by
+ insufficient checks in accessors of Exception.__context__.
+
- Issue #5604: non-ASCII characters in module name passed to
imp.find_module() were converted to UTF-8 while the path is
converted to the default filesystem encoding, causing nonsense.