cpython/Misc/NEWS.d/3.5.1.rst

.. bpo: 25709
.. date: 9452
.. nonce: OPX2TS
.. release date: 2015-12-06
.. section: Core and Builtins

Fixed problem with in-place string concatenation and utf-8 cache.

..

.. bpo: 25715
.. date: 9451
.. nonce: 3LLYLj
.. section: Windows

Python 3.5.1 installer shows wrong upgrade path and incorrect logic for
launcher detection.