Urllib3

====================

* 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)

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* 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)

===================

* Drop support for EOL Python 3.4 (Pull 1774)

* Optimize _encode_invalid_chars (Pull 1787)

===================

* 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)

===================

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

===================

* 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)