-------------

Released 2019-07-08

-   The ``flask.json_available`` flag was added back for compatibility
 with some extensions. It will raise a deprecation warning when used,
 and will be removed in version 2.0.0. :issue:`3288`

-------------

Released 2019-07-04

-   Bump minimum Werkzeug version to >= 0.15.
-   Drop support for Python 3.4.
-   Error handlers for ``InternalServerError`` or ``500`` will always be
 passed an instance of ``InternalServerError``. If they are invoked
 due to an unhandled exception, that original exception is now
 available as ``e.original_exception`` rather than being passed
 directly to the handler. The same is true if the handler is for the
 base ``HTTPException``. This makes error handler behavior more
 consistent. :pr:`3266`

 -   :meth:`Flask.finalize_request` is called for all unhandled
     exceptions even if there is no ``500`` error handler.

-   :attr:`Flask.logger` takes the same name as
 :attr:`Flask.name` (the value passed as
 ``Flask(import_name)``. This reverts 1.0's behavior of always
 logging to ``"flask.app"``, in order to support multiple apps in the
 same process. A warning will be shown if old configuration is
 detected that needs to be moved. :issue:`2866`
-   :meth:`flask.RequestContext.copy` includes the current session
 object in the request context copy. This prevents ``session``
 pointing to an out-of-date object. :issue:`2935`
-   Using built-in RequestContext, unprintable Unicode characters in
 Host header will result in a HTTP 400 response and not HTTP 500 as
 previously. :pr:`2994`
-   :func:`send_file` supports :class:`~os.PathLike` objects as
 described in PEP 0519, to support :mod:`pathlib` in Python 3.
 :pr:`3059`
-   :func:`send_file` supports :class:`~io.BytesIO` partial content.
 :issue:`2957`
-   :func:`open_resource` accepts the "rt" file mode. This still does
 the same thing as "r". :issue:`3163`
-   The :attr:`MethodView.methods` attribute set in a base class is used
 by subclasses. :issue:`3138`
-   :attr:`Flask.jinja_options` is a ``dict`` instead of an
 ``ImmutableDict`` to allow easier configuration. Changes must still
 be made before creating the environment. :pr:`3190`
-   Flask's ``JSONMixin`` for the request and response wrappers was
 moved into Werkzeug. Use Werkzeug's version with Flask-specific
 support. This bumps the Werkzeug dependency to >= 0.15.
 :issue:`3125`
-   The ``flask`` command entry point is simplified to take advantage
 of Werkzeug 0.15's better reloader support. This bumps the Werkzeug
 dependency to >= 0.15. :issue:`3022`
-   Support ``static_url_path`` that ends with a forward slash.
 :issue:`3134`
-   Support empty ``static_folder`` without requiring setting an empty
 ``static_url_path`` as well. :pr:`3124`
-   :meth:`jsonify` supports :class:`dataclasses.dataclass` objects.
 :pr:`3195`
-   Allow customizing the :attr:`Flask.url_map_class` used for routing.
 :pr:`3069`
-   The development server port can be set to 0, which tells the OS to
 pick an available port. :issue:`2926`
-   The return value from :meth:`cli.load_dotenv` is more consistent
 with the documentation. It will return ``False`` if python-dotenv is
 not installed, or if the given path isn't a file. :issue:`2937`
-   Signaling support has a stub for the ``connect_via`` method when
 the Blinker library is not installed. :pr:`3208`
-   Add an ``--extra-files`` option to the ``flask run`` CLI command to
 specify extra files that will trigger the reloader on change.
 :issue:`2897`
-   Allow returning a dictionary from a view function. Similar to how
 returning a string will produce a ``text/html`` response, returning
 a dict will call ``jsonify`` to produce a ``application/json``
 response. :pr:`3111`
-   Blueprints have a ``cli`` Click group like ``app.cli``. CLI commands
 registered with a blueprint will be available as a group under the
 ``flask`` command. :issue:`1357`.
-   When using the test client as a context manager (``with client:``),
 all preserved request contexts are popped when the block exits,
 ensuring nested contexts are cleaned up correctly. :pr:`3157`
-   Show a better error message when the view return type is not
 supported. :issue:`3214`
-   ``flask.testing.make_test_environ_builder()`` has been deprecated in
 favour of a new class ``flask.testing.EnvironBuilder``. :pr:`3232`
-   The ``flask run`` command no longer fails if Python is not built
 with SSL support. Using the ``--cert`` option will show an
 appropriate error message. :issue:`3211`
-   URL matching now occurs after the request context is pushed, rather
 than when it's created. This allows custom URL converters to access
 the app and request contexts, such as to query a database for an id.
 :issue:`3088`

-------------

Released 2019-07-04

-   The key information for ``BadRequestKeyError`` is no longer cleared
 outside debug mode, so error handlers can still access it. This
 requires upgrading to Werkzeug 0.15.5. :issue:`3249`
-   ``send_file`` url quotes the ":" and "/" characters for more
 compatible UTF-8 filename support in some browsers. :issue:`3074`
-   Fixes for PEP451 import loaders and pytest 5.x. :issue:`3275`
-   Show message about dotenv on stderr instead of stdout. :issue:`3285`

-------------

Released 2019-05-17

-   :func:`send_file` encodes filenames as ASCII instead of Latin-1
 (ISO-8859-1). This fixes compatibility with Gunicorn, which is
 stricter about header encodings than PEP 3333. :issue:`2766`
-   Allow custom CLIs using ``FlaskGroup`` to set the debug flag without
 it always being overwritten based on environment variables.
 :pr:`2765`
-   ``flask --version`` outputs Werkzeug's version and simplifies the
 Python version. :pr:`2825`
-   :func:`send_file` handles an ``attachment_filename`` that is a
 native Python 2 string (bytes) with UTF-8 coded bytes. :issue:`2933`
-   A catch-all error handler registered for ``HTTPException`` will not
 handle ``RoutingException``, which is used internally during
 routing. This fixes the unexpected behavior that had been introduced
 in 1.0. :pr:`2986`
-   Passing the ``json`` argument to ``app.test_client`` does not
 push/pop an extra app context. :issue:`2900`

-------------

Released 2018-05-02

-   Fix more backwards compatibility issues with merging slashes between
 a blueprint prefix and route. :pr:`2748`
-   Fix error with ``flask routes`` command when there are no routes.
 :issue:`2751`

-------------

Released 2018-04-29

-   Fix registering partials (with no ``__name__``) as view functions.
 :pr:`2730`
-   Don't treat lists returned from view functions the same as tuples.
 Only tuples are interpreted as response data. :issue:`2736`
-   Extra slashes between a blueprint's ``url_prefix`` and a route URL
 are merged. This fixes some backwards compatibility issues with the
 change in 1.0. :issue:`2731`, :issue:`2742`
-   Only trap ``BadRequestKeyError`` errors in debug mode, not all
 ``BadRequest`` errors. This allows ``abort(400)`` to continue
 working as expected. :issue:`2735`
-   The ``FLASK_SKIP_DOTENV`` environment variable can be set to ``1``
 to skip automatically loading dotenv files. :issue:`2722`

-----------

Released 2018-04-26

-   Python 2.6 and 3.3 are no longer supported.
-   Bump minimum dependency versions to the latest stable versions:
 Werkzeug >= 0.14, Jinja >= 2.10, itsdangerous >= 0.24, Click >= 5.1.
 :issue:`2586`
-   Skip :meth:`app.run <Flask.run>` when a Flask application is run
 from the command line. This avoids some behavior that was confusing
 to debug.
-   Change the default for :data:`JSONIFY_PRETTYPRINT_REGULAR` to
 ``False``. :func:`~json.jsonify` returns a compact format by
 default, and an indented format in debug mode. :pr:`2193`
-   :meth:`Flask.__init__ <Flask>` accepts the ``host_matching``
 argument and sets it on :attr:`~Flask.url_map`. :issue:`1559`
-   :meth:`Flask.__init__ <Flask>` accepts the ``static_host`` argument
 and passes it as the ``host`` argument when defining the static
 route. :issue:`1559`
-   :func:`send_file` supports Unicode in ``attachment_filename``.
 :pr:`2223`
-   Pass ``_scheme`` argument from :func:`url_for` to
 :meth:`~Flask.handle_url_build_error`. :pr:`2017`
-   :meth:`~Flask.add_url_rule` accepts the
 ``provide_automatic_options`` argument to disable adding the
 ``OPTIONS`` method. :pr:`1489`
-   :class:`~views.MethodView` subclasses inherit method handlers from
 base classes. :pr:`1936`
-   Errors caused while opening the session at the beginning of the
 request are handled by the app's error handlers. :pr:`2254`
-   Blueprints gained :attr:`~Blueprint.json_encoder` and
 :attr:`~Blueprint.json_decoder` attributes to override the app's
 encoder and decoder. :pr:`1898`
-   :meth:`Flask.make_response` raises ``TypeError`` instead of
 ``ValueError`` for bad response types. The error messages have been
 improved to describe why the type is invalid. :pr:`2256`
-   Add ``routes`` CLI command to output routes registered on the
 application. :pr:`2259`
-   Show warning when session cookie domain is a bare hostname or an IP
 address, as these may not behave properly in some browsers, such as
 Chrome. :pr:`2282`
-   Allow IP address as exact session cookie domain. :pr:`2282`
-   ``SESSION_COOKIE_DOMAIN`` is set if it is detected through
 ``SERVER_NAME``. :pr:`2282`
-   Auto-detect zero-argument app factory called ``create_app`` or
 ``make_app`` from ``FLASK_APP``. :pr:`2297`
-   Factory functions are not required to take a ``script_info``
 parameter to work with the ``flask`` command. If they take a single
 parameter or a parameter named ``script_info``, the
 :class:`~cli.ScriptInfo` object will be passed. :pr:`2319`
-   ``FLASK_APP`` can be set to an app factory, with arguments if
 needed, for example ``FLASK_APP=myproject.app:create_app('dev')``.
 :pr:`2326`
-   ``FLASK_APP`` can point to local packages that are not installed in
 editable mode, although ``pip install -e`` is still preferred.
 :pr:`2414`
-   The :class:`~views.View` class attribute
 :attr:`~views.View.provide_automatic_options` is set in
 :meth:`~views.View.as_view`, to be detected by
 :meth:`~Flask.add_url_rule`. :pr:`2316`
-   Error handling will try handlers registered for ``blueprint, code``,
 ``app, code``, ``blueprint, exception``, ``app, exception``.
 :pr:`2314`
-   ``Cookie`` is added to the response's ``Vary`` header if the session
 is accessed at all during the request (and not deleted). :pr:`2288`
-   :meth:`~Flask.test_request_context` accepts ``subdomain`` and
 ``url_scheme`` arguments for use when building the base URL.
 :pr:`1621`
-   Set :data:`APPLICATION_ROOT` to ``'/'`` by default. This was already
 the implicit default when it was set to ``None``.
-   :data:`TRAP_BAD_REQUEST_ERRORS` is enabled by default in debug mode.
 ``BadRequestKeyError`` has a message with the bad key in debug mode
 instead of the generic bad request message. :pr:`2348`
-   Allow registering new tags with
 :class:`~json.tag.TaggedJSONSerializer` to support storing other
 types in the session cookie. :pr:`2352`
-   Only open the session if the request has not been pushed onto the
 context stack yet. This allows :func:`~stream_with_context`
 generators to access the same session that the containing view uses.
 :pr:`2354`
-   Add ``json`` keyword argument for the test client request methods.
 This will dump the given object as JSON and set the appropriate
 content type. :pr:`2358`
-   Extract JSON handling to a mixin applied to both the
 :class:`Request` and :class:`Response` classes. This adds the
 :meth:`~Response.is_json` and :meth:`~Response.get_json` methods to
 the response to make testing JSON response much easier. :pr:`2358`
-   Removed error handler caching because it caused unexpected results
 for some exception inheritance hierarchies. Register handlers
 explicitly for each exception if you want to avoid traversing the
 MRO. :pr:`2362`
-   Fix incorrect JSON encoding of aware, non-UTC datetimes. :pr:`2374`
-   Template auto reloading will honor debug mode even even if
 :attr:`~Flask.jinja_env` was already accessed. :pr:`2373`
-   The following old deprecated code was removed. :issue:`2385`

 -   ``flask.ext`` - import extensions directly by their name instead
     of through the ``flask.ext`` namespace. For example,
     ``import flask.ext.sqlalchemy`` becomes
     ``import flask_sqlalchemy``.
 -   ``Flask.init_jinja_globals`` - extend
     :meth:`Flask.create_jinja_environment` instead.
 -   ``Flask.error_handlers`` - tracked by
     :attr:`Flask.error_handler_spec`, use :meth:`Flask.errorhandler`
     to register handlers.
 -   ``Flask.request_globals_class`` - use
     :attr:`Flask.app_ctx_globals_class` instead.
 -   ``Flask.static_path`` - use :attr:`Flask.static_url_path`
     instead.
 -   ``Request.module`` - use :attr:`Request.blueprint` instead.

-   The :attr:`Request.json` property is no longer deprecated.
 :issue:`1421`
-   Support passing a :class:`~werkzeug.test.EnvironBuilder` or ``dict``
 to :meth:`test_client.open <werkzeug.test.Client.open>`. :pr:`2412`
-   The ``flask`` command and :meth:`Flask.run` will load environment
 variables from ``.env`` and ``.flaskenv`` files if python-dotenv is
 installed. :pr:`2416`
-   When passing a full URL to the test client, the scheme in the URL is
 used instead of :data:`PREFERRED_URL_SCHEME`. :pr:`2430`
-   :attr:`Flask.logger` has been simplified. ``LOGGER_NAME`` and
 ``LOGGER_HANDLER_POLICY`` config was removed. The logger is always
 named ``flask.app``. The level is only set on first access, it
 doesn't check :attr:`Flask.debug` each time. Only one format is
 used, not different ones depending on :attr:`Flask.debug`. No
 handlers are removed, and a handler is only added if no handlers are
 already configured. :pr:`2436`
-   Blueprint view function names may not contain dots. :pr:`2450`
-   Fix a ``ValueError`` caused by invalid ``Range`` requests in some
 cases. :issue:`2526`
-   The development server uses threads by default. :pr:`2529`
-   Loading config files with ``silent=True`` will ignore
 :data:`~errno.ENOTDIR` errors. :pr:`2581`
-   Pass ``--cert`` and ``--key`` options to ``flask run`` to run the
 development server over HTTPS. :pr:`2606`
-   Added :data:`SESSION_COOKIE_SAMESITE` to control the ``SameSite``
 attribute on the session cookie. :pr:`2607`
-   Added :meth:`~flask.Flask.test_cli_runner` to create a Click runner
 that can invoke Flask CLI commands for testing. :pr:`2636`
-   Subdomain matching is disabled by default and setting
 :data:`SERVER_NAME` does not implicitly enable it. It can be enabled
 by passing ``subdomain_matching=True`` to the ``Flask`` constructor.
 :pr:`2635`
-   A single trailing slash is stripped from the blueprint
 ``url_prefix`` when it is registered with the app. :pr:`2629`
-   :meth:`Request.get_json` doesn't cache the result if parsing fails
 when ``silent`` is true. :issue:`2651`
-   :func:`Request.get_json` no longer accepts arbitrary encodings.
 Incoming JSON should be encoded using UTF-8 per :rfc:`8259`, but
 Flask will autodetect UTF-8, -16, or -32. :pr:`2691`
-   Added :data:`MAX_COOKIE_SIZE` and :attr:`Response.max_cookie_size`
 to control when Werkzeug warns about large cookies that browsers may
 ignore. :pr:`2693`
-   Updated documentation theme to make docs look better in small
 windows. :pr:`2709`
-   Rewrote the tutorial docs and example project to take a more
 structured approach to help new users avoid common pitfalls.
 :pr:`2676`

--------------

Released 2018-04-29

-   Repackage 0.12.3 to fix package layout issue. :issue:`2728`

--------------

Released 2018-04-26

-   :func:`Request.get_json` no longer accepts arbitrary encodings.
 Incoming JSON should be encoded using UTF-8 per :rfc:`8259`, but
 Flask will autodetect UTF-8, -16, or -32. :issue:`2692`
-   Fix a Python warning about imports when using ``python -m flask``.
 :issue:`2666`
-   Fix a ``ValueError`` caused by invalid ``Range`` requests in some
 cases.

--------------

Released 2017-05-16

-   Fix a bug in ``safe_join`` on Windows.

--------------

Released 2017-03-31

-   Prevent ``flask run`` from showing a ``NoAppException`` when an
 ``ImportError`` occurs within the imported application module.
-   Fix encoding behavior of ``app.config.from_pyfile`` for Python 3.
 :issue:`2118`
-   Use the ``SERVER_NAME`` config if it is present as default values
 for ``app.run``. :issue:`2109`, :pr:`2152`
-   Call ``ctx.auto_pop`` with the exception object instead of ``None``,
 in the event that a ``BaseException`` such as ``KeyboardInterrupt``
 is raised in a request handler.