MQTT is not re-subscribing after reconnect

[iamceph]

In what version(s) of Spring Integration are you seeing this issue?

6.0.2 with Spring Boot 3.0.2

Describe the bug

When the client loses connection (and auto-reconnect is on) and then reconnects, existing subscriptions are not re-subscribbed. Application restart is needed to re-subscribe.

To Reproduce

• Start the sample application
• Connect to the MQTT broker
• Send message
• Stop the MQTT broker
• Start the MQTT broker
• Send message

After the reconnection, no message will appear in the sample application.

Expected behavior

I expect to re-subscribe to the topic and receive messages

Sample

The sample includes MQTT broker in the infra folder.

Sample Here.

Original thread on StackOverflow

[artembilan]

So, the idea is to ignore a reconnect param of the connectComplete() and always re-subscribe.