This may lead to out-of-order notifications, but this is better than not having
notifications at all.

* Skip ActivityPub Announces of non-public objects

* Skip OStatus reblogs of non-public statuses

This makes slightly more sense, and ensures that the author of a post is always referenced in the audience (which some servers might rely on). And the announce is POSTed to the author's inbox anyways.

* Fix actors accepting invalid URI schemes or different host between URI and URL

* Fix statuses accepting invalid URI scheme or different host to actor

* Adjust tests to new requirements

* Improve readability of mismatching_origin?/invalid_origin? methods

* Don't normalize URLs in toots

URL normalization is ill-defined and may cause certain links to break.

* Change specs since we are not normalizing user-provided URLs

* Allow to dereference Follow object for ActivityPub

* Accept IRI as object representation for Accept activity

* Sanitize classlist properly

* Actually properly sanitize every class after the first

* Improve Formatter spec to check for multiple classes and non-space whitespace

There's no reason for an Account record to persist after Delete->Actor is received. SuspendAccountService is necessary to make sure deleted toots get sent over streaming API properly and home feeds get cleaned up. By removing Account record, we can ensure that if in the future the account is restored remotely (or username reused), it can start with a clean slate.

* Add GET /api/v1/instance/peers API to reveal known domains

* Add GET /api/v1/instance/activity API

* Make new APIs disableable, exclude private statuses from activity stats

* Fix code style issue

* Fix week timestamps

* Add semi-support for Video/Image objects in ActivityPub

Video and Image objects will create corresponding status records
with manually crafted text contents (title + URL)

* Extract html-url-finding logic into JsonLdHelper

* Fallback to id when url missing, extract supported object types

* Avoid sending explicit Undo->Announce when original deleted

* Do not forward a reply back to the server that sent it

* Deduplicate inboxes of rebloggers' followers for delete forwarding

* Adjust test

* Fix wrong class, bad SQL, wrong variable, outdated comment

* Allow hiding of reblogs from followed users

This adds a new entry to the account menu to allow users to hide
future reblogs from a user (and then if they've done that, to show
future reblogs instead).

This does not remove or add historical reblogs from/to the user's
timeline; it only affects new statuses.

The API for this operates by sending a "reblogs" key to the follow
endpoint. If this is sent when starting a new follow, it will be
respected from the beginning of the follow relationship (even if
the follow request must be approved by the followee). If this is
sent when a follow relationship already exists, it will simply
update the existing follow relationship. As with the notification
muting, this will now return an object ({reblogs: [true|false]}) or
false for each follow relationship when requesting relationship
information for an account. This should cause few issues due to an
object being truthy in many languages, but some modifications may
need to be made in pickier languages.

Database changes: adds a show_reblogs column (default true,
non-nullable) to the follows and follow_requests tables. Because
these are non-nullable, we use the existing MigrationHelpers to
perform this change without locking those tables, although the
tables are likely to be small anyway.

Tests included.

See also <https://github.com/glitch-soc/mastodon/pull/212>.

* Rubocop fixes

* Code review changes

* Test fixes

This patchset closes #648 and resolves #3271.

* Rubocop fix

* Revert reblogs defaulting in argument, fix tests

It turns out we needed this for the same reason we needed it in muting:
if nil gets passed in somehow (most usually by an API client not passing
any value), we need to detect and handle it.

We could specify a default in the parameter and then also catch nil, but
there's no great reason to duplicate the default value.

* Serialize moved accounts into REST and ActivityPub APIs

* Parse federated moved accounts from ActivityPub

* Add note about moved accounts to public profiles

* Add moved account message to web UI

* Fix code style issues

* Add structure for lists

* Add list timeline streaming API

* Add list APIs, bind list-account relation to follow relation

* Add API for adding/removing accounts from lists

* Add pagination to lists API

* Add pagination to list accounts API

* Adjust scopes for new APIs

- Creating and modifying lists merely requires "write" scope
- Fetching information about lists merely requires "read" scope

* Add test for wrong user context on list timeline

* Clean up tests

* Scrub text of html before detecting language.

* Detect language on statuses coming from activitypub.

* Fix rubocop comments.

* Remove custom emoji from text before language detection

* Clean up reblog-tracking sets from FeedManager

Builds on #5419, with a few minor optimizations and cleanup of sets
after they are no longer needed.

* Update tests, fix multiply-reblogged case

Previously, we would have lost the fact that a given status was
reblogged if the displayed reblog of it was removed, now we don't.

Also added tests to make sure FeedManager#trim cleans up our reblog
tracking keys, fixed up FeedCleanupScheduler to use the right loop,
and fixed the test for it.

* Keep references to all reblogs of a status on home feed

When inserting reblog: Add to set of reblogs of this status on
the feed, if original status was present in the feed, add it to
that set as well.

When removing a reblog: Remove it from that set. Take random
remaining item from the set. If one exists, re-insert it into feed,
otherwise do not re-insert anything.

Fix #4210

* When original is removed, toss out reblog references

Fix #5398

Ordering the home timeline query by account_id meant that the first
100 items belonged to a single account. There was also no reason to
reverse-iterate over the statuses. Assuming the user accesses the
feed halfway-through, it's better to have recent statuses already
available at the top. Therefore working from newer->older is ideal.

If the algorithm ends up filtering all items out during last-mile
filtering, repeat again a page further. The algorithm terminates
when either at least one item has been added, or if the database
query returns nothing (end of data reached)

We've changed un-reblogging behavior when we implement Snowflake, to insert un-reblogged status at the position reblogging status existed.

However, our API expects home timeline is ordered by status ids, and max_id/since_id filters by zset score. Due to this, un-reblogged status appears as a last item of result set, and timeline expansion may skips many statuses.

So this reverts that change...reblogged status inserted at corresponding position to its id.

* Add option to reduce motion

* Use HOC to wrap all Motion calls

* fix case-sensitive issue

* Avoid updating too frequently

* Get rid of unnecessary change to _simple_status.html.haml

This allows deletion of reblogs which delivered before with OStatus URI.

This error occurred at least in development environment

- For some reason, :if option on before_action did not work. It got
  executed every time, returned false, and the action run anyway,
  which led to the current_sign_in_at and sign_in_count being
  updated on every request
- Return "do not filter" early in FeedManager#filter_from_home? if
  the status is authored by receiver. Usually this method is not
  called for own statuses at all, but it is called when Feed#get
  uses the database
- Return early if #reload_stale_associations! has nothing to load
  to save a database query with WHERE 1=0

Do NOT send "delete" through streaming API when unmerging from
home timeline. "delete" implies that the original status was
deleted, which is not true!

Regression from #4801

- Rename Mastodon::TimestampIds into Mastodon::Snowflake for clarity
- Skip for statuses coming from inbox, aka delivered in real-time
- Skip for statuses that claim to be from the future

* Encode custom emojis as resolveable objects in ActivityPub

* Improve code style