This is a bugfix release: # Broker * Fix compliance with `max_inflight_messages` when a non-clean session client reconnects. Closes one of the issues on bug #1237389. # Client library * Fix incorrect inflight message accounting, which caused messages to go * unsent. Partial fix for bug #1237351. * Fix potential memory corruption when sending QoS>0 messages at a high rate using the threaded interface. Further fix for #1237351. * Fix incorrect delay scaling when exponential_backoff=true in mosquitto_reconnect_delay_set(). * Some pep8 fixes for Python.