Public Note objects that aren't addressed to their creator's followers still appear in the home timeline

[grishka]

Steps to reproduce the problem

1. Send a Create{Note} activity to a Mastodon server, where the Note does not contain the followers collection neither in to nor cc, but does contain as:Public in to

Expected behaviour

The post should not be shown in the home timeline because it is not addressed to its author's followers.

Actual behaviour

The post does appear in the home timeline.

Detailed description

The screenshot of the post showing up as if I posted it to my followers when I did not:

The ActivityPub object:

{
  "type": "Note",
  "id": "https://friends.grishka.me/posts/1027840",
  "attachment": [
    {
      "type": "Image",
      "blurhash": "USI;u9?G%M%2~WxaM|WBM|IoM{WBIoj[xas;",
      "width": 650,
      "height": 616,
      "url": "https://friends.grishka.me/i/v5zGUuqv8lDRz0UAZfkGsYZE9_feqD74zntGV7XCTiw/q:93/bG9jYWw6Ly8vcy91cGxvYWRzLzAxLzAwLzAwL2pMUC1NcGRveXV5VGZYbTVJVkZSMXoydl85YzhWUkVGVUNDby53ZWJw.jpg",
      "mediaType": "image/jpeg"
    }
  ],
  "attributedTo": "https://friends.grishka.me/users/1",
  "content": "<p>Я правильно понимаю, что по-болгарски это вполне произносимо?</p>",
  "published": "2024-03-03T05:51:17Z",
  "url": "https://friends.grishka.me/posts/1027840",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "https://friends.grishka.me/users/162969"
  ],
  "cc": [],
  "replies": {
    "type": "Collection",
    "id": "https://friends.grishka.me/posts/1027840/replies",
    "first": {
      "type": "CollectionPage",
      "items": [],
      "partOf": "https://friends.grishka.me/posts/1027840/replies",
      "next": "https://friends.grishka.me/posts/1027840/replies?page=1"
    }
  },
  "sensitive": false,
  "target": {
    "type": "Collection",
    "id": "https://friends.grishka.me/users/162969/wall",
    "attributedTo": "https://friends.grishka.me/users/162969"
  },
  "likes": "https://friends.grishka.me/posts/1027840/likes",
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "toot": "http://joinmastodon.org/ns#",
      "blurhash": "toot:blurhash",
      "sensitive": "as:sensitive"
    }
  ]
}

This is a wall-to-wall post between two users who both are on my server. The server runs Smithereen.

Mastodon instance

mastodon.social

Mastodon version

v4.3.0-nightly.2024-02-23

Technical details

No response