LWT messages no longer contain tst timestamp in 2.5.0 and 2.5.3

[mcnewton]

• App build number: 2.5.0 (420500002)
• Android version: 14
• Device: OnePlus 9
• Installation source: Google Play Store

Since 2.5.0, the lwt messages (MQTT) no longer contain the tst timestamp.

This isn't a huge concern, I import all MQTT messages into Elasticsearch and if there is no timestamp then they get the current time at import. LWTs aren't that interesting, and time of import is usually fine.

However if normal logging fail for any reason, I will process and re-import data recorded by recorder. When doing this, all LWTs end up inserted at the time of import rather than when they were generated. I could parse the timestamp written by recorder, but I'm lazy :) - it's still not accurate though, as it's not when the LWT was generated.

As noted on Mastodon, this could be created_at instead. I'm not really sure it makes much difference for LWT. For location, tst and created_at may be different. For LWTs, they are both the same value. In theory the correct solution is to leave tst (regression from previous behaviour) and also add created_at (to fill in complete data to match location messages), but I'm not sure it's really worth having both. Personal preference would probably be to just add tst back and not worry about it.

[jpmens]

Thank you for the report, @mcnewton: I agree with your evaluation. tst should come back, and we could add created_at (which is the more precise term) additionally.

[jpmens]

2.5.3 here. LWT doesn't contain tst:

{"_type": "lwt"}

[growse]

Eurgh, I had a test for this.