--- /dev/null
+What's new in the next version of Tornado
+=========================================
+
+In Progress
+-----------
+
+Backwards-compatibility notes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* ``SSLIOStream.connect`` and `.IOStream.start_tls` now validate certificates
+ by default.
+* Certificate validation will now use the system CA root certificates instead
+ of ``certifi`` when possible (i.e. Python 2.7.9+ or 3.4+). This includes
+ `.IOStream` and ``simple_httpclient``, but not ``curl_httpclient``.
+* The default SSL configuration has become stricter, using
+ `ssl.create_default_context` where available.
+
+
+`tornado.gen`
+~~~~~~~~~~~~~
+
+* On Python 3, catching an exception in a coroutine no longer leads to
+ leaks via ``Exception.__context__``.
+
+`tornado.ioloop`
+~~~~~~~~~~~~~~~~
+
+* `.PeriodicCallback` is now more efficient when the clock jumps forward
+ by a large amount.
+
+`tornado.iostream`
+~~~~~~~~~~~~~~~~~~
+
+* ``SSLIOStream.connect`` and `.IOStream.start_tls` now validate certificates
+ by default.
+
+`tornado.log`
+~~~~~~~~~~~~~
+
+* `.define_logging_options` now works correctly when given a non-default
+ ``options`` object.
+
+``tornado.simple_httpclient``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* Improved performance on Python 3 by reusing a single `ssl.SSLContext`.
+
+`tornado.util`
+~~~~~~~~~~~~~~
+
+* `.import_object` now supports unicode strings on Python 2.
+
+`tornado.web`
+~~~~~~~~~~~~~
+
+* Passing ``secure=False`` or ``httponly=False`` to
+ `.RequestHandler.set_cookie` now works as expected (previously only the
+ presence of the argument was considered and its value was ignored).
+
+`tornado.websocket`
+~~~~~~~~~~~~~~~~~~~
+
+* The ``on_close`` method will no longer be called more than once.
def define_logging_options(options=None):
+ """Add logging-related flags to ``options``.
+
+ These options are present automatically on the default options instance;
+ this method is only necessary if you have created your own `.OptionParser`.
+
+ .. versionadded:: 4.2
+ This function existed in prior versions but was broken and undocumented until 4.2.
+ """
if options is None:
# late import to prevent cycle
from tornado.options import options