2.3.0 (2024-12-22)
==================

Features
--------

- Added ``HTTPResponse.shutdown()`` to stop any ongoing or future reads for a specific response. It calls ``shutdown(SHUT_RD)`` on the underlying socket. This feature was `sponsored by LaunchDarkly <https://opencollective.com/urllib3/contributions/815307>`__. (`#2868 <https://github.com/urllib3/urllib3/issues/2868>`__)
- Added support for JavaScript Promise Integration on Emscripten. This enables more efficient WebAssembly 
  requests and streaming, and makes it possible to use in Node.js if you launch it as  ``node --experimental-wasm-stack-switching``. (`#3400 <https://github.com/urllib3/urllib3/issues/3400>`__)
- Added the ``proxy_is_tunneling`` property to ``HTTPConnection`` and ``HTTPSConnection``. (`#3285 <https://github.com/urllib3/urllib3/issues/3285>`__)
- Added pickling support to ``NewConnectionError`` and ``NameResolutionError``. (`#3480 <https://github.com/urllib3/urllib3/issues/3480>`__)


Bugfixes
--------

- Fixed an issue in debug logs where the HTTP version was rendering as "HTTP/11" instead of "HTTP/1.1". (`#3489 <https://github.com/urllib3/urllib3/issues/3489>`__)


Deprecations and Removals
-------------------------

- Removed support for Python 3.8. (`#3492 <https://github.com/urllib3/urllib3/issues/3492>`__)


2.2.3 (2024-09-12)
==================

Features
--------

- Added support for Python 3.13. (`#3473 <https://github.com/urllib3/urllib3/issues/3473>`__)

Bugfixes
--------

- Fixed the default encoding of chunked request bodies to be UTF-8 instead of ISO-8859-1.
  All other methods of supplying a request body already use UTF-8 starting in urllib3 v2.0. (`#3053 <https://github.com/urllib3/urllib3/issues/3053>`__)
- Fixed ResourceWarning on CONNECT with Python < 3.11.4 by backporting https://github.com/python/cpython/issues/103472. (`#3252 <https://github.com/urllib3/urllib3/issues/3252>`__)
- Adjust tolerance for floating-point comparison on Windows to avoid flakiness in CI (`#3413 <https://github.com/urllib3/urllib3/issues/3413>`__)
- Fixed a crash where certain standard library hash functions were absent in restricted environments. (`#3432 <https://github.com/urllib3/urllib3/issues/3432>`__)
- Fixed mypy error when adding to ``HTTPConnection.default_socket_options``. (`#3448 <https://github.com/urllib3/urllib3/issues/3448>`__)

HTTP/2 (experimental)
---------------------

HTTP/2 support is still in early development.

- Excluded Transfer-Encoding: chunked from HTTP/2 request body (`#3425 <https://github.com/urllib3/urllib3/issues/3425>`__)
- Added version checking for ``h2`` (https://pypi.org/project/h2/) usage.

  Now only accepting supported h2 major version 4.x.x. (`#3290 <https://github.com/urllib3/urllib3/issues/3290>`__)
- Added a probing mechanism for determining whether a given target origin
  supports HTTP/2 via ALPN. (`#3301 <https://github.com/urllib3/urllib3/issues/3301>`__)
- Add support for sending a request body with HTTP/2 (`#3302 <https://github.com/urllib3/urllib3/issues/3302>`__)


Deprecations and Removals
-------------------------

- Note for downstream distributors: the ``_version.py`` file has been removed and is now created at build time by hatch-vcs. (`#3412 <https://github.com/urllib3/urllib3/issues/3412>`__)
- Drop support for end-of-life PyPy3.8 and PyPy3.9. (`#3475 <https://github.com/urllib3/urllib3/issues/3475>`__)


2.2.2 (2024-06-17)
==================

- Added the ``Proxy-Authorization`` header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via ``Retry.remove_headers_on_redirect``.
- Allowed passing negative integers as ``amt`` to read methods of ``http.client.HTTPResponse`` as an alternative to ``None``. (`#3122 <https://github.com/urllib3/urllib3/issues/3122>`__)
- Fixed return types representing copying actions to use ``typing.Self``. (`#3363 <https://github.com/urllib3/urllib3/issues/3363>`__)

2.2.1 (2024-02-16)
==================

- Fixed issue where ``InsecureRequestWarning`` was emitted for HTTPS connections when using Emscripten. (`#3331 <https://github.com/urllib3/urllib3/issues/3331>`__)
- Fixed ``HTTPConnectionPool.urlopen`` to stop automatically casting non-proxy headers to ``HTTPHeaderDict``. This change was premature as it did not apply to proxy headers and ``HTTPHeaderDict`` does not handle byte header values correctly yet. (`#3343 <https://github.com/urllib3/urllib3/issues/3343>`__)
- Changed ``InvalidChunkLength`` to ``ProtocolError`` when response terminates before the chunk length is sent. (`#2860 <https://github.com/urllib3/urllib3/issues/2860>`__)
- Changed ``ProtocolError`` to be more verbose on incomplete reads with excess content. (`#3261 <https://github.com/urllib3/urllib3/issues/3261>`__)


2.2.0 (2024-01-30)
==================

- Added support for `Emscripten and Pyodide <https://urllib3.readthedocs.io/en/latest/reference/contrib/emscripten.html>`__, including streaming support in cross-origin isolated browser environments where threading is enabled. (`#2951 <https://github.com/urllib3/urllib3/issues/2951>`__)
- Added support for ``HTTPResponse.read1()`` method. (`#3186 <https://github.com/urllib3/urllib3/issues/3186>`__)
- Added rudimentary support for HTTP/2. (`#3284 <https://github.com/urllib3/urllib3/issues/3284>`__)
- Fixed issue where requests against urls with trailing dots were failing due to SSL errors
  when using proxy. (`#2244 <https://github.com/urllib3/urllib3/issues/2244>`__)
- Fixed ``HTTPConnection.proxy_is_verified`` and ``HTTPSConnection.proxy_is_verified``
  to be always set to a boolean after connecting to a proxy. It could be
  ``None`` in some cases previously. (`#3130 <https://github.com/urllib3/urllib3/issues/3130>`__)
- Fixed an issue where ``headers`` passed in a request with ``json=`` would be mutated (`#3203 <https://github.com/urllib3/urllib3/issues/3203>`__)
- Fixed ``HTTPSConnection.is_verified`` to be set to ``False`` when connecting
  from a HTTPS proxy to an HTTP target. It was set to ``True`` previously. (`#3267 <https://github.com/urllib3/urllib3/issues/3267>`__)
- Fixed handling of new error message from OpenSSL 3.2.0 when configuring an HTTP proxy as HTTPS (`#3268 <https://github.com/urllib3/urllib3/issues/3268>`__)
- Fixed TLS 1.3 post-handshake auth when the server certificate validation is disabled (`#3325 <https://github.com/urllib3/urllib3/issues/3325>`__)
- Note for downstream distributors: To run integration tests, you now need to run the tests a second
  time with the ``--integration`` pytest flag. (`#3181 <https://github.com/urllib3/urllib3/issues/3181>`__)


2.1.0 (2023-11-13)
==================

- Removed support for the deprecated urllib3[secure] extra. (`#2680 <https://github.com/urllib3/urllib3/issues/2680>`__)
- Removed support for the deprecated SecureTransport TLS implementation. (`#2681 <https://github.com/urllib3/urllib3/issues/2681>`__)
- Removed support for the end-of-life Python 3.7. (`#3143 <https://github.com/urllib3/urllib3/issues/3143>`__)
- Allowed loading CA certificates from memory for proxies. (`#3065 <https://github.com/urllib3/urllib3/issues/3065>`__)
- Fixed decoding Gzip-encoded responses which specified ``x-gzip`` content-encoding. (`#3174 <https://github.com/urllib3/urllib3/issues/3174>`__)


2.0.7 (2023-10-17)
==================

* Made body stripped from HTTP requests changing the request method to GET after HTTP 303 "See Other" redirect responses.


2.0.6 (2023-10-02)
==================

* Added the ``Cookie`` header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via ``Retry.remove_headers_on_redirect``.


2.0.5 (2023-09-20)
==================

- Allowed pyOpenSSL third-party module without any deprecation warning. (`#3126 <https://github.com/urllib3/urllib3/issues/3126>`__)
- Fixed default ``blocksize`` of ``HTTPConnection`` classes to match high-level classes. Previously was 8KiB, now 16KiB. (`#3066 <https://github.com/urllib3/urllib3/issues/3066>`__)


2.0.4 (2023-07-19)
==================

- Added support for union operators to ``HTTPHeaderDict`` (`#2254 <https://github.com/urllib3/urllib3/issues/2254>`__)
- Added ``BaseHTTPResponse`` to ``urllib3.__all__`` (`#3078 <https://github.com/urllib3/urllib3/issues/3078>`__)
- Fixed ``urllib3.connection.HTTPConnection`` to raise the ``http.client.connect`` audit event to have the same behavior as the standard library HTTP client (`#2757 <https://github.com/urllib3/urllib3/issues/2757>`__)
- Relied on the standard library for checking hostnames in supported PyPy releases (`#3087 <https://github.com/urllib3/urllib3/issues/3087>`__)


2.0.3 (2023-06-07)
==================

- Allowed alternative SSL libraries such as LibreSSL, while still issuing a warning as we cannot help users facing issues with implementations other than OpenSSL. (`#3020 <https://github.com/urllib3/urllib3/issues/3020>`__)
- Deprecated URLs which don't have an explicit scheme (`#2950 <https://github.com/urllib3/urllib3/pull/2950>`_)
- Fixed response decoding with Zstandard when compressed data is made of several frames. (`#3008 <https://github.com/urllib3/urllib3/issues/3008>`__)
- Fixed ``assert_hostname=False`` to correctly skip hostname check. (`#3051 <https://github.com/urllib3/urllib3/issues/3051>`__)


2.0.2 (2023-05-03)
==================

- Fixed ``HTTPResponse.stream()`` to continue yielding bytes if buffered decompressed data
  was still available to be read even if the underlying socket is closed. This prevents
  a compressed response from being truncated. (`#3009 <https://github.com/urllib3/urllib3/issues/3009>`__)


2.0.1 (2023-04-30)
==================

- Fixed a socket leak when fingerprint or hostname verifications fail. (`#2991 <https://github.com/urllib3/urllib3/issues/2991>`__)
- Fixed an error when ``HTTPResponse.read(0)`` was the first ``read`` call or when the internal response body buffer was otherwise empty. (`#2998 <https://github.com/urllib3/urllib3/issues/2998>`__)


2.0.0 (2023-04-26)
==================

Read the `v2.0 migration guide <https://urllib3.readthedocs.io/en/latest/v2-migration-guide.html>`__ for help upgrading to the latest version of urllib3.

Removed
-------

* Removed support for Python 2.7, 3.5, and 3.6 (`#883 <https://github.com/urllib3/urllib3/issues/883>`__, `#2336 <https://github.com/urllib3/urllib3/issues/2336>`__).
* Removed fallback on certificate ``commonName`` in ``match_hostname()`` function.
  This behavior was deprecated in May 2000 in RFC 2818. Instead only ``subjectAltName``
  is used to verify the hostname by default. To enable verifying the hostname against
  ``commonName`` use ``SSLContext.hostname_checks_common_name = True`` (`#2113 <https://github.com/urllib3/urllib3/issues/2113>`__).
* Removed support for Python with an ``ssl`` module compiled with LibreSSL, CiscoSSL,
  wolfSSL, and all other OpenSSL alternatives. Python is moving to require OpenSSL with PEP 644 (`#2168 <https://github.com/urllib3/urllib3/issues/2168>`__).
* Removed support for OpenSSL versions earlier than 1.1.1 or that don't have SNI support.
  When an incompatible OpenSSL version is detected an ``ImportError`` is raised (`#2168 <https://github.com/urllib3/urllib3/issues/2168>`__).
* Removed the list of default ciphers for OpenSSL 1.1.1+ and SecureTransport as their own defaults are already secure (`#2082 <https://github.com/urllib3/urllib3/issues/2082>`__).
* Removed ``urllib3.contrib.appengine.AppEngineManager`` and support for Google App Engine Standard Environment (`#2044 <https://github.com/urllib3/urllib3/issues/2044>`__).
* Removed deprecated ``Retry`` options ``method_whitelist``, ``DEFAULT_REDIRECT_HEADERS_BLACKLIST`` (`#2086 <https://github.com/urllib3/urllib3/issues/2086>`__).
* Removed ``urllib3.HTTPResponse.from_httplib`` (`#2648 <https://github.com/urllib3/urllib3/issues/2648>`__).
* Removed default value of ``None`` for the ``request_context`` parameter of ``urllib3.PoolManager.connection_from_pool_key``. This change should have no effect on users as the default value of ``None`` was an invalid option and was never used (`#1897 <https://github.com/urllib3/urllib3/issues/1897>`__).
* Removed the ``urllib3.request`` module. ``urllib3.request.RequestMethods`` has been made a private API.
  This change was made to ensure that ``from urllib3 import request`` imported the top-level ``request()``
  function instead of the ``urllib3.request`` module (`#2269 <https://github.com/urllib3/urllib3/issues/2269>`__).
* Removed support for SSLv3.0 from the ``urllib3.contrib.pyopenssl`` even when support is available from the compiled OpenSSL library (`#2233 <https://github.com/urllib3/urllib3/issues/2233>`__).
* Removed the deprecated ``urllib3.contrib.ntlmpool`` module (`#2339 <https://github.com/urllib3/urllib3/issues/2339>`__).
* Removed ``DEFAULT_CIPHERS``, ``HAS_SNI``, ``USE_DEFAULT_SSLCONTEXT_CIPHERS``, from the private module ``urllib3.util.ssl_`` (`#2168 <https://github.com/urllib3/urllib3/issues/2168>`__).
* Removed ``urllib3.exceptions.SNIMissingWarning`` (`#2168 <https://github.com/urllib3/urllib3/issues/2168>`__).
* Removed the ``_prepare_conn`` method from ``HTTPConnectionPool``. Previously this was only used to call ``HTTPSConnection.set_cert()`` by ``HTTPSConnectionPool`` (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Removed ``tls_in_tls_required`` property from ``HTTPSConnection``. This is now determined from the ``scheme`` parameter in ``HTTPConnection.set_tunnel()`` (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Removed the ``strict`` parameter/attribute from ``HTTPConnection``, ``HTTPSConnection``, ``HTTPConnectionPool``, ``HTTPSConnectionPool``, and ``HTTPResponse`` (`#2064 <https://github.com/urllib3/urllib3/issues/2064>`__).

Deprecated
----------

* Deprecated ``HTTPResponse.getheaders()`` and ``HTTPResponse.getheader()`` which will be removed in urllib3 v2.1.0. Instead use ``HTTPResponse.headers`` and ``HTTPResponse.headers.get(name, default)``. (`#1543 <https://github.com/urllib3/urllib3/issues/1543>`__, `#2814 <https://github.com/urllib3/urllib3/issues/2814>`__).
* Deprecated ``urllib3.contrib.pyopenssl`` module which will be removed in urllib3 v2.1.0 (`#2691 <https://github.com/urllib3/urllib3/issues/2691>`__).
* Deprecated ``urllib3.contrib.securetransport`` module which will be removed in urllib3 v2.1.0 (`#2692 <https://github.com/urllib3/urllib3/issues/2692>`__).
* Deprecated ``ssl_version`` option in favor of ``ssl_minimum_version``. ``ssl_version`` will be removed in urllib3 v2.1.0 (`#2110 <https://github.com/urllib3/urllib3/issues/2110>`__).
* Deprecated the ``strict`` parameter of ``PoolManager.connection_from_context()`` as it's not longer needed in Python 3.x. It will be removed in urllib3 v2.1.0 (`#2267 <https://github.com/urllib3/urllib3/issues/2267>`__)
* Deprecated the ``NewConnectionError.pool`` attribute which will be removed in urllib3 v2.1.0 (`#2271 <https://github.com/urllib3/urllib3/issues/2271>`__).
* Deprecated ``format_header_param_html5`` and ``format_header_param`` in favor of ``format_multipart_header_param`` (`#2257 <https://github.com/urllib3/urllib3/issues/2257>`__).
* Deprecated ``RequestField.header_formatter`` parameter which will be removed in urllib3 v2.1.0 (`#2257 <https://github.com/urllib3/urllib3/issues/2257>`__).
* Deprecated ``HTTPSConnection.set_cert()`` method. Instead pass parameters to the ``HTTPSConnection`` constructor (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Deprecated ``HTTPConnection.request_chunked()`` method which will be removed in urllib3 v2.1.0. Instead pass ``chunked=True`` to ``HTTPConnection.request()`` (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).

Added
-----

* Added top-level ``urllib3.request`` function which uses a preconfigured module-global ``PoolManager`` instance (`#2150 <https://github.com/urllib3/urllib3/issues/2150>`__).
* Added the ``json`` parameter to ``urllib3.request()``, ``PoolManager.request()``, and ``ConnectionPool.request()`` methods to send JSON bodies in requests. Using this parameter will set the header ``Content-Type: application/json`` if ``Content-Type`` isn't already defined.
  Added support for parsing JSON response bodies with ``HTTPResponse.json()`` method (`#2243 <https://github.com/urllib3/urllib3/issues/2243>`__).
* Added type hints to the ``urllib3`` module (`#1897 <https://github.com/urllib3/urllib3/issues/1897>`__).
* Added ``ssl_minimum_version`` and ``ssl_maximum_version`` options which set
  ``SSLContext.minimum_version`` and ``SSLContext.maximum_version`` (`#2110 <https://github.com/urllib3/urllib3/issues/2110>`__).
* Added support for Zstandard (RFC 8878) when ``zstandard`` 1.18.0 or later is installed.
  Added the ``zstd`` extra which installs the ``zstandard`` package (`#1992 <https://github.com/urllib3/urllib3/issues/1992>`__).
* Added ``urllib3.response.BaseHTTPResponse`` class. All future response classes will be subclasses of ``BaseHTTPResponse`` (`#2083 <https://github.com/urllib3/urllib3/issues/2083>`__).
* Added ``FullPoolError`` which is raised when ``PoolManager(block=True)`` and a connection is returned to a full pool (`#2197 <https://github.com/urllib3/urllib3/issues/2197>`__).
* Added ``HTTPHeaderDict`` to the top-level ``urllib3`` namespace (`#2216 <https://github.com/urllib3/urllib3/issues/2216>`__).
* Added support for configuring header merging behavior with HTTPHeaderDict
  When using a ``HTTPHeaderDict`` to provide headers for a request, by default duplicate
  header values will be repeated. But if ``combine=True`` is passed into a call to
  ``HTTPHeaderDict.add``, then the added header value will be merged in with an existing
  value into a comma-separated list (``X-My-Header: foo, bar``) (`#2242 <https://github.com/urllib3/urllib3/issues/2242>`__).
* Added ``NameResolutionError`` exception when a DNS error occurs (`#2305 <https://github.com/urllib3/urllib3/issues/2305>`__).
* Added ``proxy_assert_hostname`` and ``proxy_assert_fingerprint`` kwargs to ``ProxyManager`` (`#2409 <https://github.com/urllib3/urllib3/issues/2409>`__).
* Added a configurable ``backoff_max`` parameter to the ``Retry`` class.
  If a custom ``backoff_max`` is provided to the ``Retry`` class, it
  will replace the ``Retry.DEFAULT_BACKOFF_MAX`` (`#2494 <https://github.com/urllib3/urllib3/issues/2494>`__).
* Added the ``authority`` property to the Url class as per RFC 3986 3.2. This property should be used in place of ``netloc`` for users who want to include the userinfo (auth) component of the URI (`#2520 <https://github.com/urllib3/urllib3/issues/2520>`__).
* Added the ``scheme`` parameter to ``HTTPConnection.set_tunnel`` to configure the scheme of the origin being tunnelled to (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Added the ``is_closed``, ``is_connected`` and ``has_connected_to_proxy`` properties to ``HTTPConnection`` (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Added optional ``backoff_jitter`` parameter to ``Retry``. (`#2952 <https://github.com/urllib3/urllib3/issues/2952>`__)

Changed
-------

* Changed ``urllib3.response.HTTPResponse.read`` to respect the semantics of ``io.BufferedIOBase`` regardless of compression. Specifically, this method:

  * Only returns an empty bytes object to indicate EOF (that is, the response has been fully consumed).
  * Never returns more bytes than requested.
  * Can issue any number of system calls: zero, one or multiple.

  If you want each ``urllib3.response.HTTPResponse.read`` call to issue a single system call, you need to disable decompression by setting ``decode_content=False`` (`#2128 <https://github.com/urllib3/urllib3/issues/2128>`__).
* Changed ``urllib3.HTTPConnection.getresponse`` to return an instance of ``urllib3.HTTPResponse`` instead of ``http.client.HTTPResponse`` (`#2648 <https://github.com/urllib3/urllib3/issues/2648>`__).
* Changed ``ssl_version`` to instead set the corresponding ``SSLContext.minimum_version``
  and ``SSLContext.maximum_version`` values.  Regardless of ``ssl_version`` passed
  ``SSLContext`` objects are now constructed using ``ssl.PROTOCOL_TLS_CLIENT`` (`#2110 <https://github.com/urllib3/urllib3/issues/2110>`__).
* Changed default ``SSLContext.minimum_version`` to be ``TLSVersion.TLSv1_2`` in line with Python 3.10 (`#2373 <https://github.com/urllib3/urllib3/issues/2373>`__).
* Changed ``ProxyError`` to wrap any connection error (timeout, TLS, DNS) that occurs when connecting to the proxy (`#2482 <https://github.com/urllib3/urllib3/pull/2482>`__).
* Changed ``urllib3.util.create_urllib3_context`` to not override the system cipher suites with
  a default value. The new default will be cipher suites configured by the operating system (`#2168 <https://github.com/urllib3/urllib3/issues/2168>`__).
* Changed ``multipart/form-data`` header parameter formatting matches the WHATWG HTML Standard as of 2021-06-10. Control characters in filenames are no longer percent encoded (`#2257 <https://github.com/urllib3/urllib3/issues/2257>`__).
* Changed the error raised when connecting via HTTPS when the ``ssl`` module isn't available from ``SSLError`` to ``ImportError`` (`#2589 <https://github.com/urllib3/urllib3/issues/2589>`__).
* Changed ``HTTPConnection.request()`` to always use lowercase chunk boundaries when sending requests with ``Transfer-Encoding: chunked`` (`#2515 <https://github.com/urllib3/urllib3/issues/2515>`__).
* Changed ``enforce_content_length`` default to True, preventing silent data loss when reading streamed responses (`#2514 <https://github.com/urllib3/urllib3/issues/2514>`__).
* Changed internal implementation of ``HTTPHeaderDict`` to use ``dict`` instead of ``collections.OrderedDict`` for better performance (`#2080 <https://github.com/urllib3/urllib3/issues/2080>`__).
* Changed the ``urllib3.contrib.pyopenssl`` module to wrap ``OpenSSL.SSL.Error`` with ``ssl.SSLError`` in ``PyOpenSSLContext.load_cert_chain`` (`#2628 <https://github.com/urllib3/urllib3/issues/2628>`__).
* Changed usage of the deprecated ``socket.error`` to ``OSError`` (`#2120 <https://github.com/urllib3/urllib3/issues/2120>`__).
* Changed all parameters in the ``HTTPConnection`` and ``HTTPSConnection`` constructors to be keyword-only except ``host`` and ``port`` (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Changed ``HTTPConnection.getresponse()`` to set the socket timeout from ``HTTPConnection.timeout`` value before reading
  data from the socket. This previously was done manually by the ``HTTPConnectionPool`` calling ``HTTPConnection.sock.settimeout(...)`` (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Changed the ``_proxy_host`` property to ``_tunnel_host`` in ``HTTPConnectionPool`` to more closely match how the property is used (value in ``HTTPConnection.set_tunnel()``) (`#1985 <https://github.com/urllib3/urllib3/issues/1985>`__).
* Changed name of ``Retry.BACK0FF_MAX`` to be ``Retry.DEFAULT_BACKOFF_MAX``.
* Changed TLS handshakes to use ``SSLContext.check_hostname`` when possible (`#2452 <https://github.com/urllib3/urllib3/pull/2452>`__).
* Changed ``server_hostname`` to behave like other parameters only used by ``HTTPSConnectionPool`` (`#2537 <https://github.com/urllib3/urllib3/pull/2537>`__).
* Changed the default ``blocksize`` to 16KB to match OpenSSL's default read amounts (`#2348 <https://github.com/urllib3/urllib3/pull/2348>`__).
* Changed ``HTTPResponse.read()`` to raise an error when calling with ``decode_content=False`` after using ``decode_content=True`` to prevent data loss (`#2800 <https://github.com/urllib3/urllib3/issues/2800>`__).

Fixed
-----

* Fixed thread-safety issue where accessing a ``PoolManager`` with many distinct origins would cause connection pools to be closed while requests are in progress (`#1252 <https://github.com/urllib3/urllib3/issues/1252>`__).
* Fixed an issue where an ``HTTPConnection`` instance would erroneously reuse the socket read timeout value from reading the previous response instead of a newly configured connect timeout.
  Instead now if ``HTTPConnection.timeout`` is updated before sending the next request the new timeout value will be used (`#2645 <https://github.com/urllib3/urllib3/issues/2645>`__).
* Fixed ``socket.error.errno`` when raised from pyOpenSSL's ``OpenSSL.SSL.SysCallError`` (`#2118 <https://github.com/urllib3/urllib3/issues/2118>`__).
* Fixed the default value of ``HTTPSConnection.socket_options`` to match ``HTTPConnection`` (`#2213 <https://github.com/urllib3/urllib3/issues/2213>`__).
* Fixed a bug where ``headers`` would be modified by the ``remove_headers_on_redirect`` feature (`#2272 <https://github.com/urllib3/urllib3/issues/2272>`__).
* Fixed a reference cycle bug in ``urllib3.util.connection.create_connection()`` (`#2277 <https://github.com/urllib3/urllib3/issues/2277>`__).
* Fixed a socket leak if ``HTTPConnection.connect()`` fails (`#2571 <https://github.com/urllib3/urllib3/pull/2571>`__).
* Fixed ``urllib3.contrib.pyopenssl.WrappedSocket`` and ``urllib3.contrib.securetransport.WrappedSocket`` close methods (`#2970 <https://github.com/urllib3/urllib3/issues/2970>`__)

1.26.20 (2024-08-29)
====================

* Fixed a crash where certain standard library hash functions were absent in
  FIPS-compliant environments.
  (`#3432 <https://github.com/urllib3/urllib3/issues/3432>`__)
* Replaced deprecated dash-separated setuptools entries in ``setup.cfg``.
  (`#3461 <https://github.com/urllib3/urllib3/pull/3461>`__)
* Took into account macOS setting ``ECONNRESET`` instead of ``EPROTOTYPE`` in
  its newer versions.
  (`#3416 <https://github.com/urllib3/urllib3/pull/3416>`__)
* Backported changes to our tests and CI configuration from v2.x to support
  testing with CPython 3.12 and 3.13.
  (`#3436 <https://github.com/urllib3/urllib3/pull/3436>`__)

1.26.19 (2024-06-17)
====================

* Added the ``Proxy-Authorization`` header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via ``Retry.remove_headers_on_redirect``.
* Fixed handling of OpenSSL 3.2.0 new error message for misconfiguring an HTTP proxy as HTTPS. (`#3405 <https://github.com/urllib3/urllib3/issues/3405>`__)

1.26.18 (2023-10-17)
====================

* Made body stripped from HTTP requests changing the request method to GET after HTTP 303 "See Other" redirect responses.

1.26.17 (2023-10-02)
====================

* Added the ``Cookie`` header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via ``Retry.remove_headers_on_redirect``. (`#3139 <https://github.com/urllib3/urllib3/pull/3139>`_)

1.26.16 (2023-05-23)
====================

* Fixed thread-safety issue where accessing a ``PoolManager`` with many distinct origins
  would cause connection pools to be closed while requests are in progress (`#2954 <https://github.com/urllib3/urllib3/pull/2954>`_)

1.26.15 (2023-03-10)
====================

* Fix socket timeout value when ``HTTPConnection`` is reused (`#2645 <https://github.com/urllib3/urllib3/issues/2645>`__)
* Remove "!" character from the unreserved characters in IPv6 Zone ID parsing
  (`#2899 <https://github.com/urllib3/urllib3/issues/2899>`__)
* Fix IDNA handling of '\x80' byte (`#2901 <https://github.com/urllib3/urllib3/issues/2901>`__)

1.26.14 (2023-01-11)
====================

* Fixed parsing of port 0 (zero) returning None, instead of 0. (`#2850 <https://github.com/urllib3/urllib3/issues/2850>`__)
* Removed deprecated getheaders() calls in contrib module. Fixed the type hint of ``PoolKey.key_retries`` by adding ``bool`` to the union. (`#2865 <https://github.com/urllib3/urllib3/issues/2865>`__)

1.26.13 (2022-11-23)
====================

* Deprecated the ``HTTPResponse.getheaders()`` and ``HTTPResponse.getheader()`` methods.
* Fixed an issue where parsing a URL with leading zeroes in the port would be rejected
  even when the port number after removing the zeroes was valid.
* Fixed a deprecation warning when using cryptography v39.0.0.
* Removed the ``<4`` in the ``Requires-Python`` packaging metadata field.

1.26.12 (2022-08-22)
====================

* Deprecated the `urllib3[secure]` extra and the `urllib3.contrib.pyopenssl` module.
  Both will be removed in v2.x. See this `GitHub issue <https://github.com/urllib3/urllib3/issues/2680>`_
  for justification and info on how to migrate.

1.26.11 (2022-07-25)
====================

* Fixed an issue where reading more than 2 GiB in a call to ``HTTPResponse.read`` would
  raise an ``OverflowError`` on Python 3.9 and earlier.

1.26.10 (2022-07-07)
====================

* Removed support for Python 3.5
* Fixed an issue where a ``ProxyError`` recommending configuring the proxy as HTTP
  instead of HTTPS could appear even when an HTTPS proxy wasn't configured.

1.26.9 (2022-03-16)
===================

* Changed ``urllib3[brotli]`` extra to favor installing Brotli libraries that are still
  receiving updates like ``brotli`` and ``brotlicffi`` instead of ``brotlipy``.
  This change does not impact behavior of urllib3, only which dependencies are installed.
* Fixed a socket leaking when ``HTTPSConnection.connect()`` raises an exception.
* Fixed ``server_hostname`` being forwarded from ``PoolManager`` to ``HTTPConnectionPool``
  when requesting an HTTP URL. Should only be forwarded when requesting an HTTPS URL.

1.26.8 (2022-01-07)
===================

* Added extra message to ``urllib3.exceptions.ProxyError`` when urllib3 detects that
  a proxy is configured to use HTTPS but the proxy itself appears to only use HTTP.
* Added a mention of the size of the connection pool when discarding a connection due to the pool being full.
* Added explicit support for Python 3.11.
* Deprecated the ``Retry.MAX_BACKOFF`` class property in favor of ``Retry.DEFAULT_MAX_BACKOFF``
  to better match the rest of the default parameter names. ``Retry.MAX_BACKOFF`` is removed in v2.0.
* Changed location of the vendored ``ssl.match_hostname`` function from ``urllib3.packages.ssl_match_hostname``
  to ``urllib3.util.ssl_match_hostname`` to ensure Python 3.10+ compatibility after being repackaged
  by downstream distributors.
* Fixed absolute imports, all imports are now relative.


1.26.7 (2021-09-22)
===================

* Fixed a bug with HTTPS hostname verification involving IP addresses and lack
  of SNI. (Issue #2400)
* Fixed a bug where IPv6 braces weren't stripped during certificate hostname
  matching. (Issue #2240)


1.26.6 (2021-06-25)
===================

* Deprecated the ``urllib3.contrib.ntlmpool`` module. urllib3 is not able to support
  it properly due to `reasons listed in this issue <https://github.com/urllib3/urllib3/issues/2282>`_.
  If you are a user of this module please leave a comment.
* Changed ``HTTPConnection.request_chunked()`` to not erroneously emit multiple
  ``Transfer-Encoding`` headers in the case that one is already specified.
* Fixed typo in deprecation message to recommend ``Retry.DEFAULT_ALLOWED_METHODS``.


1.26.5 (2021-05-26)
===================

* Fixed deprecation warnings emitted in Python 3.10.
* Updated vendored ``six`` library to 1.16.0.
* Improved performance of URL parser when splitting
  the authority component.


1.26.4 (2021-03-15)
===================

* Changed behavior of the default ``SSLContext`` when connecting to HTTPS proxy
  during HTTPS requests. The default ``SSLContext`` now sets ``check_hostname=True``.


1.26.3 (2021-01-26)
===================

* Fixed bytes and string comparison issue with headers (Pull #2141)

* Changed ``ProxySchemeUnknown`` error message to be
  more actionable if the user supplies a proxy URL without
  a scheme. (Pull #2107)


1.26.2 (2020-11-12)
===================

* Fixed an issue where ``wrap_socket`` and ``CERT_REQUIRED`` wouldn't
  be imported properly on Python 2.7.8 and earlier (Pull #2052)


1.26.1 (2020-11-11)
===================

* Fixed an issue where two ``User-Agent`` headers would be sent if a
  ``User-Agent`` header key is passed as ``bytes`` (Pull #2047)


1.26.0 (2020-11-10)
===================

* **NOTE: urllib3 v2.0 will drop support for Python 2**.
  `Read more in the v2.0 Roadmap <https://urllib3.readthedocs.io/en/latest/v2-roadmap.html>`_.

* Added support for HTTPS proxies contacting HTTPS servers (Pull #1923, Pull #1806)

* Deprecated negotiating TLSv1 and TLSv1.1 by default. Users that
  still wish to use TLS earlier than 1.2 without a deprecation warning
  should opt-in explicitly by setting ``ssl_version=ssl.PROTOCOL_TLSv1_1`` (Pull #2002)
  **Starting in urllib3 v2.0: Connections that receive a ``DeprecationWarning`` will fail**

* Deprecated ``Retry`` options ``Retry.DEFAULT_METHOD_WHITELIST``, ``Retry.DEFAULT_REDIRECT_HEADERS_BLACKLIST``
  and ``Retry(method_whitelist=...)`` in favor of ``Retry.DEFAULT_ALLOWED_METHODS``,
  ``Retry.DEFAULT_REMOVE_HEADERS_ON_REDIRECT``, and ``Retry(allowed_methods=...)``
  (Pull #2000) **Starting in urllib3 v2.0: Deprecated options will be removed**

* Added default ``User-Agent`` header to every request (Pull #1750)

* Added ``urllib3.util.SKIP_HEADER`` for skipping ``User-Agent``, ``Accept-Encoding``,
  and ``Host`` headers from being automatically emitted with requests (Pull #2018)

* Collapse ``transfer-encoding: chunked`` request data and framing into
  the same ``socket.send()`` call (Pull #1906)

* Send ``http/1.1`` ALPN identifier with every TLS handshake by default (Pull #1894)

* Properly terminate SecureTransport connections when CA verification fails (Pull #1977)

* Don't emit an ``SNIMissingWarning`` when passing ``server_hostname=None``
  to SecureTransport (Pull #1903)

* Disabled requesting TLSv1.2 session tickets as they weren't being used by urllib3 (Pull #1970)

* Suppress ``BrokenPipeError`` when writing request body after the server
  has closed the socket (Pull #1524)

* Wrap ``ssl.SSLError`` that can be raised from reading a socket (e.g. "bad MAC")
  into an ``urllib3.exceptions.SSLError`` (Pull #1939)


1.25.11 (2020-10-19)
====================

* Fix retry backoff time parsed from ``Retry-After`` header when given
  in the HTTP date format. The HTTP date was parsed as the local timezone
  rather than accounting for the timezone in the HTTP date (typically
  UTC) (Pull #1932, Pull #1935, Pull #1938, Pull #1949)

* Fix issue where an error would be raised when the ``SSLKEYLOGFILE``
  environment variable was set to the empty string. Now ``SSLContext.keylog_file``
  is not set in this situation (Pull #2016)


1.25.10 (2020-07-22)
====================

* Added support for ``SSLKEYLOGFILE`` environment variable for
  logging TLS session keys with use with programs like
  Wireshark for decrypting captured web traffic (Pull #1867)

* Fixed loading of SecureTransport libraries on macOS Big Sur
  due to the new dynamic linker cache (Pull #1905)

* Collapse chunked request bodies data and framing into one
  call to ``send()`` to reduce the number of TCP packets by 2-4x (Pull #1906)

* Don't insert ``None`` into ``ConnectionPool`` if the pool
  was empty when requesting a connection (Pull #1866)

* Avoid ``hasattr`` call in ``BrotliDecoder.decompress()`` (Pull #1858)


1.25.9 (2020-04-16)
===================

* Added ``InvalidProxyConfigurationWarning`` which is raised when
  erroneously specifying an HTTPS proxy URL. urllib3 doesn't currently
  support connecting to HTTPS proxies but will soon be able to
  and we would like users to migrate properly without much breakage.

  See `this GitHub issue <https://github.com/urllib3/urllib3/issues/1850>`_
  for more information on how to fix your proxy config. (Pull #1851)

* Drain connection after ``PoolManager`` redirect (Pull #1817)

* Ensure ``load_verify_locations`` raises ``SSLError`` for all backends (Pull #1812)

* Rename ``VerifiedHTTPSConnection`` to ``HTTPSConnection`` (Pull #1805)

* Allow the CA certificate data to be passed as a string (Pull #1804)

* Raise ``ValueError`` if method contains control characters (Pull #1800)

* Add ``__repr__`` to ``Timeout`` (Pull #1795)


1.25.8 (2020-01-20)
===================

* Drop support for EOL Python 3.4 (Pull #1774)

* Optimize _encode_invalid_chars (Pull #1787)


1.25.7 (2019-11-11)
===================

* Preserve ``chunked`` parameter on retries (Pull #1715, Pull #1734)

* Allow unset ``SERVER_SOFTWARE`` in App Engine (Pull #1704, Issue #1470)

* Fix issue where URL fragment was sent within the request target. (Pull #1732)

* Fix issue where an empty query section in a URL would fail to parse. (Pull #1732)

* Remove TLS 1.3 support in SecureTransport due to Apple removing support (Pull #1703)


1.25.6 (2019-09-24)
===================

* Fix issue where tilde (``~``) characters were incorrectly
  percent-encoded in the path. (Pull #1692)


1.25.5 (2019-09-19)
===================

* Add mitigation for BPO-37428 affecting Python <3.7.4 and OpenSSL 1.1.1+ which
  caused certificate verification to be enabled when using ``cert_reqs=CERT_NONE``.
  (Issue #1682)


1.25.4 (2019-09-19)
===================

* Propagate Retry-After header settings to subsequent retries. (Pull #1607)

* Fix edge case where Retry-After header was still respected even when
  explicitly opted out of. (Pull #1607)

* Remove dependency on ``rfc3986`` for URL parsing.

* Fix issue where URLs containing invalid characters within ``Url.auth`` would
  raise an exception instead of percent-encoding those characters.

* Add support for ``HTTPResponse.auto_close = False`` which makes HTTP responses
  work well with BufferedReaders and other ``io`` module features. (Pull #1652)

* Percent-encode invalid characters in URL for ``HTTPConnectionPool.request()`` (Pull #1673)


1.25.3 (2019-05-23)
===================

* Change ``HTTPSConnection`` to load system CA certificates
  when ``ca_certs``, ``ca_cert_dir``, and ``ssl_context`` are
  unspecified. (Pull #1608, Issue #1603)

* Upgrade bundled rfc3986 to v1.3.2. (Pull #1609, Issue #1605)


1.25.2 (2019-04-28)
===================

* Change ``is_ipaddress`` to not detect IPvFuture addresses. (Pull #1583)

* Change ``parse_url`` to percent-encode invalid characters within the
  path, query, and target components. (Pull #1586)


1.25.1 (2019-04-24)
===================

* Add support for Google's ``Brotli`` package. (Pull #1572, Pull #1579)

* Upgrade bundled rfc3986 to v1.3.1 (Pull #1578)


1.25 (2019-04-22)
=================

* Require and validate certificates by default when using HTTPS (Pull #1507)

* Upgraded ``urllib3.utils.parse_url()`` to be RFC 3986 compliant. (Pull #1487)

* Added support for ``key_password`` for ``HTTPSConnectionPool`` to use
  encrypted ``key_file`` without creating your own ``SSLContext`` object. (Pull #1489)

* Add TLSv1.3 support to CPython, pyOpenSSL, and SecureTransport ``SSLContext``
  implementations. (Pull #1496)

* Switched the default multipart header encoder from RFC 2231 to HTML 5 working draft. (Issue #303, Pull #1492)

* Fixed issue where OpenSSL would block if an encrypted client private key was
  given and no password was given. Instead an ``SSLError`` is raised. (Pull #1489)

* Added support for Brotli content encoding. It is enabled automatically if
  ``brotlipy`` package is installed which can be requested with
  ``urllib3[brotli]`` extra. (Pull #1532)

* Drop ciphers using DSS key exchange from default TLS cipher suites.
  Improve default ciphers when using SecureTransport. (Pull #1496)

* Implemented a more efficient ``HTTPResponse.__iter__()`` method. (Issue #1483)

1.24.3 (2019-05-01)
===================

* Apply fix for CVE-2019-9740. (Pull #1591)

1.24.2 (2019-04-17)
===================

* Don't load system certificates by default when any other ``ca_certs``, ``ca_certs_dir`` or
  ``ssl_context`` parameters are specified.

* Remove Authorization header regardless of case when redirecting to cross-site. (Issue #1510)

* Add support for IPv6 addresses in subjectAltName section of certificates. (Issue #1269)


1.24.1 (2018-11-02)
===================

* Remove quadratic behavior within ``GzipDecoder.decompress()`` (Issue #1467)

* Restored functionality of ``ciphers`` parameter for ``create_urllib3_context()``. (Issue #1462)


1.24 (2018-10-16)
=================

* Allow key_server_hostname to be specified when initializing a PoolManager to allow custom SNI to be overridden. (Pull #1449)

* Test against Python 3.7 on AppVeyor. (Pull #1453)

* Early-out ipv6 checks when running on App Engine. (Pull #1450)

* Change ambiguous description of backoff_factor (Pull #1436)

* Add ability to handle multiple Content-Encodings (Issue #1441 and Pull #1442)

* Skip DNS names that can't be idna-decoded when using pyOpenSSL (Issue #1405).

* Add a server_hostname parameter to HTTPSConnection which allows for
  overriding the SNI hostname sent in the handshake. (Pull #1397)

* Drop support for EOL Python 2.6 (Pull #1429 and Pull #1430)

* Fixed bug where responses with header Content-Type: message/* erroneously
  raised HeaderParsingError, resulting in a warning being logged. (Pull #1439)

* Move urllib3 to src/urllib3 (Pull #1409)


1.23 (2018-06-04)
=================

* Allow providing a list of headers to strip from requests when redirecting
  to a different host. Defaults to the ``Authorization`` header. Different
  headers can be set via ``Retry.remove_headers_on_redirect``. (Issue #1316)

* Fix ``util.selectors._fileobj_to_fd`` to accept ``long`` (Issue #1247).

* Dropped Python 3.3 support. (Pull #1242)

* Put the connection back in the pool when calling stream() or read_chunked() on
  a chunked HEAD response. (Issue #1234)

* Fixed pyOpenSSL-specific ssl client authentication issue when clients
  attempted to auth via certificate + chain (Issue #1060)

* Add the port to the connectionpool connect print (Pull #1251)

* Don't use the ``uuid`` module to create multipart data boundaries. (Pull #1380)

* ``read_chunked()`` on a closed response returns no chunks. (Issue #1088)

* Add Python 2.6 support to ``contrib.securetransport`` (Pull #1359)

* Added support for auth info in url for SOCKS proxy (Pull #1363)


1.22 (2017-07-20)
=================

* Fixed missing brackets in ``HTTP CONNECT`` when connecting to IPv6 address via
  IPv6 proxy. (Issue #1222)

* Made the connection pool retry on ``SSLError``.  The original ``SSLError``
  is available on ``MaxRetryError.reason``. (Issue #1112)

* Drain and release connection before recursing on retry/redirect.  Fixes
  deadlocks with a blocking connectionpool. (Issue #1167)

* Fixed compatibility for cookiejar. (Issue #1229)

* pyopenssl: Use vendored version of ``six``. (Issue #1231)


1.21.1 (2017-05-02)
===================

* Fixed SecureTransport issue that would cause long delays in response body
  delivery. (Pull #1154)

* Fixed regression in 1.21 that threw exceptions when users passed the
  ``socket_options`` flag to the ``PoolManager``.  (Issue #1165)

* Fixed regression in 1.21 that threw exceptions when users passed the
  ``assert_hostname`` or ``assert_fingerprint`` flag to the ``PoolManager``.
  (Pull #1157)


1.21 (2017-04-25)
=================

* Improved performance of certain selector system calls on Python 3.5 and
  later. (Pull #1095)

* Resolved issue where the PyOpenSSL backend would not wrap SysCallError
  exceptions appropriately when sending data. (Pull #1125)

* Selectors now detects a monkey-patched select module after import for modules
  that patch the select module like eventlet, greenlet. (Pull #1128)

* Reduced memory consumption when streaming zlib-compressed responses
  (as opposed to raw deflate streams). (Pull #1129)

* Connection pools now use the entire request context when constructing the
  pool key. (Pull #1016)

* ``PoolManager.connection_from_*`` methods now accept a new keyword argument,
  ``pool_kwargs``, which are merged with the existing ``connection_pool_kw``.
  (Pull #1016)

* Add retry counter for ``status_forcelist``. (Issue #1147)

* Added ``contrib`` module for using SecureTransport on macOS:
  ``urllib3.contrib.securetransport``.  (Pull #1122)

* urllib3 now only normalizes the case of ``http://`` and ``https://`` schemes:
  for schemes it does not recognise, it assumes they are case-sensitive and
  leaves them unchanged.
  (Issue #1080)


1.20 (2017-01-19)
=================

* Added support for waiting for I/O using selectors other than select,
  improving urllib3's behaviour with large numbers of concurrent connections.
  (Pull #1001)

* Updated the date for the system clock check. (Issue #1005)

* ConnectionPools now correctly consider hostnames to be case-insensitive.
  (Issue #1032)

* Outdated versions of PyOpenSSL now cause the PyOpenSSL contrib module
  to fail when it is injected, rather than at first use. (Pull #1063)

* Outdated versions of cryptography now cause the PyOpenSSL contrib module
  to fail when it is injected, rather than at first use. (Issue #1044)

* Automatically attempt to rewind a file-like body object when a request is
  retried or redirected. (Pull #1039)

* Fix some bugs that occur when modules incautiously patch the queue module.
  (Pull #1061)

* Prevent retries from occurring on read timeouts for which the request method
  was not in the method whitelist. (Issue #1059)

* Changed the PyOpenSSL contrib module to lazily load idna to avoid
  unnecessarily bloating the memory of programs that don't need it. (Pull
  #1076)

* Add support for IPv6 literals with zone identifiers. (Pull #1013)

* Added support for socks5h:// and socks4a:// schemes when working with SOCKS
  proxies, and controlled remote DNS appropriately. (Issue #1035)


1.19.1 (2016-11-16)
===================

* Fixed AppEngine import that didn't function on Python 3.5. (Pull #1025)


1.19 (2016-11-03)
=================

* urllib3 now respects Retry-After headers on 413, 429, and 503 responses when
  using the default retry logic. (Pull #955)

* Remove markers from setup.py to assist ancient setuptools versions. (Issue
  #986)

* Disallow superscripts and other integerish things in URL ports. (Issue #989)

* Allow urllib3's HTTPResponse.stream() method to continue to work with
  non-httplib underlying FPs. (Pull #990)

* Empty filenames in multipart headers are now emitted as such, rather than
  being suppressed. (Issue #1015)

* Prefer user-supplied Host headers on chunked uploads. (Issue #1009)


1.18.1 (2016-10-27)
===================

* CVE-2016-9015. Users who are using urllib3 version 1.17 or 1.18 along with
  PyOpenSSL injection and OpenSSL 1.1.0 *must* upgrade to this version. This
  release fixes a vulnerability whereby urllib3 in the above configuration
  would silently fail to validate TLS certificates due to erroneously setting
  invalid flags in OpenSSL's ``SSL_CTX_set_verify`` function. These erroneous
  flags do not cause a problem in OpenSSL versions before 1.1.0, which
  interprets the presence of any flag as requesting certificate validation.

  There is no PR for this patch, as it was prepared for simultaneous disclosure
  and release. The master branch received the same fix in Pull #1010.


1.18 (2016-09-26)
=================

* Fixed incorrect message for IncompleteRead exception. (Pull #973)

* Accept ``iPAddress`` subject alternative name fields in TLS certificates.
  (Issue #258)

* Fixed consistency of ``HTTPResponse.closed`` between Python 2 and 3.
  (Issue #977)

* Fixed handling of wildcard certificates when using PyOpenSSL. (Issue #979)


1.17 (2016-09-06)
=================

* Accept ``SSLContext`` objects for use in SSL/TLS negotiation. (Issue #835)

* ConnectionPool debug log now includes scheme, host, and port. (Issue #897)

* Substantially refactored documentation. (Issue #887)

* Used URLFetch default timeout on AppEngine, rather than hardcoding our own.
  (Issue #858)

* Normalize the scheme and host in the URL parser (Issue #833)

* ``HTTPResponse`` contains the last ``Retry`` object, which now also
  contains retries history. (Issue #848)

* Timeout can no longer be set as boolean, and must be greater than zero.
  (Pull #924)

* Removed pyasn1 and ndg-httpsclient from dependencies used for PyOpenSSL. We
  now use cryptography and idna, both of which are already dependencies of
  PyOpenSSL. (Pull #930)

* Fixed infinite loop in ``stream`` when amt=None. (Issue #928)

* Try to use the operating system's certificates when we are using an
  ``SSLContext``. (Pull #941)

* Updated cipher suite list to allow ChaCha20+Poly1305. AES-GCM is preferred to
  ChaCha20, but ChaCha20 is then preferred to everything else. (Pull #947)

* Updated cipher suite list to remove 3DES-based cipher suites. (Pull #958)

* Removed the cipher suite fallback to allow HIGH ciphers. (Pull #958)

* Implemented ``length_remaining`` to determine remaining content
  to be read. (Pull #949)

* Implemented ``enforce_content_length`` to enable exceptions when
  incomplete data chunks are received. (Pull #949)

* Dropped connection start, dropped connection reset, redirect, forced retry,
  and new HTTPS connection log levels to DEBUG, from INFO. (Pull #967)


1.16 (2016-06-11)
=================

* Disable IPv6 DNS when IPv6 connections are not possible. (Issue #840)

* Provide ``key_fn_by_scheme`` pool keying mechanism that can be
  overridden. (Issue #830)

* Normalize scheme and host to lowercase for pool keys, and include
  ``source_address``. (Issue #830)

* Cleaner exception chain in Python 3 for ``_make_request``.
  (Issue #861)

* Fixed installing ``urllib3[socks]`` extra. (Issue #864)

* Fixed signature of ``ConnectionPool.close`` so it can actually safely be
  called by subclasses. (Issue #873)

* Retain ``release_conn`` state across retries. (Issues #651, #866)

* Add customizable ``HTTPConnectionPool.ResponseCls``, which defaults to
  ``HTTPResponse`` but can be replaced with a subclass. (Issue #879)


1.15.1 (2016-04-11)
===================

* Fix packaging to include backports module. (Issue #841)


1.15 (2016-04-06)
=================

* Added Retry(raise_on_status=False). (Issue #720)

* Always use setuptools, no more distutils fallback. (Issue #785)

* Dropped support for Python 3.2. (Issue #786)

* Chunked transfer encoding when requesting with ``chunked=True``.
  (Issue #790)

* Fixed regression with IPv6 port parsing. (Issue #801)

* Append SNIMissingWarning messages to allow users to specify it in
  the PYTHONWARNINGS environment variable. (Issue #816)

* Handle unicode headers in Py2. (Issue #818)

* Log certificate when there is a hostname mismatch. (Issue #820)

* Preserve order of request/response headers. (Issue #821)


1.14 (2015-12-29)
=================

* contrib: SOCKS proxy support! (Issue #762)

* Fixed AppEngine handling of transfer-encoding header and bug
