Question: Was there ever code to send to subscribed instances when a comment is end-user-deleted or mod-removed?

[RocketDerp]

Question

For this situation, you have to have at least 3 servers. ServerA being the home for a community, and a user on ServerB deleting their own comment, which will delete local, federate to ServerA and be deleted on 2 of the servers. However, there seems to be no code to deliver the delete to ServerC (or any more than the first 2 servers).

In contrast, editing of a comment works with 3 or more servers fine. A comment edit comes in to RawAnnouncableActivities function receive and hits this code,

lemmy/crates/apub/src/activities/community/announce.rs

Line 60 in e9e7654

// send to community followers

    // send to community followers
    if community.local {
      verify_person_in_community(&actor_id, &community, data).await?;
      AnnounceActivity::send(self, &community, data).await?;
    }

But deletes are not RawAnnouncableActivities and instead go directly into ActivityHandler for Delete function receive, which has no logic to send to community followers.

lemmy/crates/apub/src/activities/deletion/delete.rs

Line 52 in e9e7654

async fn receive(self, context: &Data<LemmyContext>) -> Result<(), LemmyError> {

NOTE: For end-users on the home instance of a community, federation does work to delete on all servers. The client API of Lemmy does have code to distribute to subscribed instances. The problem happens when your end-user who comments then deletes-comment is on a server other than the one that is home for the community. To coin a term, federation-incoming-repeater to federation peers.

Questions:

1. Did this ever get tested and work that anyone on the project can recall? version of Lemmy, git commits, etc?
2. Should a delete be hitting the RawAnnouncableActivities receive code path?
3. Does it look like this was just an oversight nobody looked for and just add some type of "send to community followers" for deletes?

If I've made some kind of big mistake here, I apologize up front. @WayneSheppard called attention to the problem and I confirmed it today in 0.18.2 live servers in #3588 - but I felt that we needed some project archaeology of past behavior. Thank you.

[Nutomic]

The sending of deleted comments is handled here. So the logic for local or remote community is the same as for other outgoing activities including edit comment (using send_activity_in_community).

RawAnnouncableActivities is only used for receiving, not for sending. Its true that the code is unclear or confusing in many ways, I appreciate that you are digging into it. It would also be useful if you add code comments so that its easier for others to understand. And writing federation tests which you are already doing.

One possibility is that this delete problem is caused by wrong routing on the receiving side, which is done in activity_lists. Basically incoming activities are deserialized with serde to the SharedInboxActivities enum, and end up as the first matching variant. So delete activities will actually be deserialized as PersonInboxActivities::Delete. I think that is fine because in the end its the same type as AnnouncableActivities::Delete which handles comment deletes as well. But tests are the only way to be sure.