Still delivering some reposts of/replies to unbridged posts

[snarfed]

Thought we caught all of these, but I guess not, some are still happening. Fortunately they get filtered out on both AP and ATProto because the in-reply-tos and repost-ofs are either blank or can't be resolved, but still.

Fediverse => Bluesky example:

• https://mastodon.mauve.moe/users/mauve/statuses/112752746470946287
• ...is a repost of https://freeradical.zone/users/rolltime/statuses/112752365722519437 , whose author is unbridged
• we stored and emitted at://did:plc:oiddmimybq2jjwyszqucfzbf/app.bsky.feed.repost/3kwscwvomcdm2 for the repost, with blank subject (below)

{
  "$type": "app.bsky.feed.repost",
  "createdAt": "2024-07-08T20:26:14.000Z",
  "subject": {
    "cid": "",
    "uri": ""
  }
}

I suspect there one or two similar edge cases for replies, protocol-independent.

[qazmlp]

That's a directly …#Public-addressed boost which may be uncommon compared to 'unlisted' ones.

(I.e. it's "to": [ "…#Public" ], "cc": [ "…/followers" ] rather than iirc the other way around.)

[snarfed]

snarfed/lexrpc#3 will help here, at least for fediverse => Bluesky.