PINGREQ packet is sent even when there was a MQTT control Packet is that duration.

[Singa17]

As per the specification , PINGREQ must be sent only when there is no MQTT control packets.
However, when we test, MQTT client publish the data and PINGREQ is also sent out.
Test Scenario:
Keep Alive = 60 seconds

Time 0s: CONNECT
Time 10s: PUBLISH is sent
Time 30s: PUBLISH is sent
Time 45s: PINGREQ is sent------------> In this scenario, there shall not be any PINGREQ. why 45s? 75% of Keep alive.
Time 50s: SUBSCRIBE
Time 70s: PUBLISH

If Keep Alive is non-zero and in the absence of sending any other MQTT Control Packets, the Client MUST 680 send a PINGREQ packet [MQTT-3.1.2-20].

[X-Ryl669]

Please use the master branch. The logic in the previous version for the Keep Alive was to PING as soon as 75% of the Keep Alive time was elapsed. This is allowed in the standard since the Keep Alive is a the maximum time without activity before the broker closes the session, so in order not to reach a premature closing, a 25% margin was used. This was working correctly for long keep alive but not very well for small one.

The current version in master branch replaced this logic by triggering sending 5s before the Keep Alive time. The Keep Alive time isn't a timer anymore, it's tracking the last activity (so it shouldn't send a ping if you publish meanwhile). Please report if it doesn't act like this for you, in that case it's a bug.