Issue #28426: Fixed potential crash in PyUnicode_AsDecodedObject() in debug build.

diff --cc Misc/NEWS
index e5d77af5f4088ccd7b36721be82a676076cccff2,ff6025c47959e373d651d4cb7b75bfc395c1c8fc..563f0c0a46702361cced44d5462d4673e12cf1b0
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,12 -10,9 +10,15 @@@ What's New in Python 3.6.0 beta 
  Core and Builtins
  -----------------
  
+ - Issue #28426: Fixed potential crash in PyUnicode_AsDecodedObject() in debug
+   build.
+ 
 +- Issue #28517: Fixed of-by-one error in the peephole optimizer that caused
 +  keeping unreachable code.
 +
 +- Issue #28214: Improved exception reporting for problematic __set_name__
 +  attributes.
 +
  - Issue #23782: Fixed possible memory leak in _PyTraceback_Add() and exception
    loss in PyTraceBack_Here().
  

diff --cc Objects/unicodeobject.c
Simple merge