Allowing shared subscriber group topics to match

[nwest1]

This looked to be a bug to me.

When I was configuring a client, and used $share/groupname/topic as the topic, no messages would be delivered.

I traced it down to here: https://github.com/eclipse/paho.mqtt.java/blob/master/org.eclipse.paho.mqttv5.client/src/main/java/org/eclipse/paho/mqttv5/client/internal/CommsCallback.java#L611

At that point, the message would have come from topic, which does not match $share/groupname/topic, and the message would be left undelivered.

possibly related https://github.com/eclipse/paho.mqtt.java/issues/827

Thank you for your time!

Signed-off-by: Nathan West Nathan.West@target.com

Please make sure that the following boxes are checked before submitting your Pull Request, thank you!

• [x] This change is against the develop branch, not master.
• [x] You have signed the Eclipse ECA
• [x] All of your commits have been signed-off with the correct email address (the same one that you used to sign the CLA) Hint: use the -s argument when committing.
• [x] If This PR fixes an issue, that you reference the issue below. OR if this is a new issue that you are fixing straight away that you add some Description about the bug and how this will fix it.
• [x] If this is new functionality, You have added the appropriate Unit tests.

[klausbetz]

@icraggs, @rdasgupt: Are there any plans to merge this PR?

This seems to be a rock-solid implementation of a MQTT Client.
It would be really helpful when this bug is fixed. Until now (v1.2.5) consumers of this package need to provide a custom callback just to get shared subscriptions to work.

[wilx]

I have hit this exact issue today. The suggested patch looks like it should fix the issue. Why is this not merged yet?