v1.5.0 - 2019-10-30
===================

* Add support for clean_session on subscribe helper. Closes #219
* Add support for non-standard bridge connection. Closes #282
* Fix hang with QoS 2 message and clean_session = False. The fix replace hang
  with message DROP. See README for known limitation. Closes #284 and #286
* Fix connection establishement timeout. Closes #291 and #288
* Add support for connecting through a proxy. Closes #315
* Add MQTT v5 support. Closes #334
* Improve error message when sending queue is full. Closes #378
* Improve error handling during initialization on edge case. Closes #387 and #388
* Allow to specify local client port used (similar to bind_address). Closes #390
* Add method is_connected to know if MQTT connection is established. Closes #414
* Set connection timeout to keepalive. Closes #425



v1.4.0 - 2018-09-02
===================

- Fix hang when client restarted and broker resumed a session with Qos2
  message. Closes #284.
  Note: this change replace the hang by a message lost ! See README for
  current limitation of paho-mqtt.
- Fix reconnection loop when a clean_session=True client reconnect while Qos2
  message are being sent.
  Note: this change replace the infinite reconnection loop by a possible
  duplicate QoS2 message. Only clean_session=True client are affected, see
  README for current limitation of paho-mqtt.
- Catch and log any exception raised by user callback. Closes #294.
- Improve support for external event loop (like asyncio). Closes #235.
- Fix order of message with publish.multiple helper. Closes #87.
- Fix hang on wait_for_published() on bad network. Closes #309.
- Fix an issue with Websocket that seems to happen only on Windows.
  Closes #268.
- Fix issue with Websocket payload size between 127 and 65536. Closes #267.
- Closes socket in client destructor to avoid FD leak. Closes #170.
- Fix uncaught timeout exception during connection. Closes #288.
- Remove dup flag on PUBREL packet. Closes #298.
- Use secure entropy source for Websocket mask_key (urandom). Closes #305.
- Fix mid generation that was not thread-safe.
- Replace print() statements with proper logging. Closes #214.
- Allow insecure TLS on publish and subscribe helpers. Closes #299.
- Allow to remove authentication (reset username to None). Closes #259.
- Add support for the non-standard bridge mode. Closes #282.


v1.3.1 - 2017-10-09
===================

- Fix reconnect_delay_set which ignored the max_delay. Closes #218.
- Fix crash when connection is lost while trying to send message. Closes #208.
- Fix issue with unicode topic when some character were multi-bytes UTF-8.
- Fix issue with empty Client ID with broker that don't support them. Closes #209.
- Fix issue with tls_set that did not allowed cert_reqs=ssl.CERT_NONE.
  Closes #123.
- Relax requirement on pytest-runner, it's now only required for tests. Closes
  #207, #227.

v1.3.0 - 2017-06-20
===================

- **BREAKING** Requires Python 2.7 or 3.4+. Closes #163.
- **BREAKING** Remove support for SSL without SSLContext (Requires Python 2.7.9+ or 3.2+).
  Closes #115.
- **BREAKING** on_connect callback is now always called flags. Previously this
  callback could accepts 3 OR 4 arguments, now it must accepts 4. Closes #197.
- **BREAKING** tls_insecure_set() must now be called *after* tls_set()
- Allow username and password to be zero length (as opposed to not being
  present). Closes #80.
- Allow zero length client ids when using MQTT v3.1.1.
- Add SSLContext support, including SNI. Closes #11.
- Improved support for unicode topic and binary payload.
  Closes #15, #16.
- Allow arbitrary Websocket headers and path.
  Closes #169.
- Fix issue with large inbound payload over Websocket. Closes #107.
- Add exponential delay for reconnection. Closes #195.
- Move unit tests to pytest (#164) and tox (#187)
- Add support for standard Python logging. Closes #95.
- Fix duplicate incoming QoS==2 message. Closes #194.

v1.2.3 - 2017-04-20
===================

- Fix possible hang of TLS connection during handshake.
  Closes #3.
- Fix issue with publish helper with TLS connection.
  Closes #180.
- Fix installation issue on non-UTF-8 system.
  Closes #181.
- Fix non-working Websocket over TLS connection.
  Closes #182.

v1.2.2 - 2017-04-11
===================

- Fix message lost when using paho.mqtt.publish helper with QoS=0 message.
  Closes #172.

v1.2.1 - 2017-04-03
===================

- Handle unicode username and passwords correctly. Closes #79.
- Fix handling of invalid UTF-8 topics on incoming messages - the library now
  does not attempt to decode the topic - this will happen when the user
  accesses msg.topic in the on_message callback. If the topic is not valid
  UTF-8, an exception will be raised. Closes #75.
- Fix issue with WebSocket connection in case of network issue (timeout or
  connection broken). Closes #105.
- Fix issue with SSL connection, where latest incoming message may be delayed
  or never processed. Closes #131.
- Fix possible message lost with publish.single and publish.multiple. Closes
  #119.


v1.2 - 2016-06-03
=================

- Client.publish() now returns an MQTTMessageInfo object. The MQTTMessageInfo
  object behaves like a tuple of (rc, mid) for backwards compatibility but
  also provides two functions: is_published() and wait_for_published().
  This allows a client to determine whether any given message has been
  published without need for a callback, and also allows the client to block
  waiting until the message has been sent.
- Further fix for Client constructor for the case where "localhost" is
  unresolvable.
- Add paho.mqtt.subscribe module, with simple() and callback() helper
  functions.
- Allow ^C to interrupt client loop.
- Fix for keepalive=0 causing an infinite disconnect/reconnect loop. Closes
  #42.
- Modify callbacks definition/structure to allow classical inheritence. Closes
  #53, #54.
- Add websockets support.
- Default MQTT version is again changed to v3.1.1.
- Client.subscribe() now accepts unicode type topic inputs on Python 2. Closes
  #16.
- paho.mqtt.publish() now raises an MQTTException on a CONNECT failure, rather
  than blindly continuing. Closes #6.
- Don't block on TLS sockets on Python 3. Closes #2.
- Client.publish() now accepts bytes() payloads on Python 3. Closes #1.
- Don't attempt to join() own thread. Closes #14.
- Allow the use of Client.message_callback_add() from inside callbacks. Closes
  #12.
- Use a monotonic time source for keeping track of time, if available. Closes
  #56.


v1.1 - 2015-01-30
=================

- Add support for wildcard certificates. Closes #440547.
- Default connection behaviour has been reverted to MQTT v3.1 instead of
  v3.1.1. There is as yet insufficient support for v3.1.1 to rely on, and
  current v3.1 implementations do not return the correct CONNACK code to allow
  detection of the fault. Closes #451735.
- Fix incorrect handling of queued messages after reconnecting. Closes
  #452672.
- Fix possible race condition if the connection in loop_start() does not
  complete before loop_stop() is called, meaning the network thread never
  ends. Closes #448428. Thanks to Kees Bakker.


v1.0.2 - 2014-09-13
===================

- Fix "protocol" not being used in publish.single()
- Fix Client constructor for the case where "localhost" is unresolvable.
  Closes #439277.
- Don't attempt to encode topic to utf-8 twice. Thanks to Luc Milland.
- Handle "unicode" type payloads on Python 2.7. Thanks to Luc Milland.
- Fix reconnecting after sending more QoS>0 messages than inflight messages is
  set to, whilst connecting.  Closes #443935. Thanks to Hiram van Paassen.
- Fix possible race condition when connecting with TLS and publishing at the
  same time, which could lead to PUBLISH data being sent before any other
  messages and unencrypted. Closes #443964. Thanks to Hiram van Paassen.
- Handle exceptions from select() in client loop() function. Closes #443881.
  Thanks to Jeff Jasper.


v1.0.1
======

- Fix incorrect reconnect that occurred if calling loop_stop() before
  disconnect().

v1.0
====

- Default protocol is now MQTT v3.1.1.
- Client will reconnect using MQTT v3.1 if a v3.1.1 connection fails due to
  the incorrect protocol version number.
- All strings are now correctly encoded as utf-8.
- Add support for "session present" flag in on_connect callback.

v0.9.1
======

- Fix CONNECT packet for MQTT v3.1.1.
- Fix potential lockup when publishing from on_publish callback.
- Add version information to paho.mqtt.__version__
