* Fix followers synchronization mechanism not working when URI has empty path

To my knowledge, there is no current implementation on the fediverse
that can use bare domains (e.g., actor is at https://example.org instead of
something like https://example.org/actor) that also plans to support the
followers synchronization mechanism. However, Mastodon's current implementation
would exclude such accounts from followers list.

Also adds tests and rename them to reflect the proper method names.

* Move url prefix regexp to its own constant

* Fix error when suspending user with an already-existing canonical email block

Fixes #17033

While attempting to create a `CanonicalEmailBlock` with an existing hash would
raise an `ActiveRecord::RecordNotUnique` error, this being done within a
transaction would cancel the whole transaction. For this reason, checking for
uniqueness in Rails would query the database within the transaction and avoid
invalidating the whole transaction for this reason.

A race condition is still possible, where multiple accounts sharing a canonical
email would be blocked in concurrent transactions, in which only one would
succeed, but that is way less likely to happen that the current issue, and can
always be retried after the first failure, unlike the current situation.

* Add tests

Broken since #15827

* Add tests

* Fix user email address being banned on self-deletion

Fixes #16498

* Change references to tootsuite/mastodon to mastodon/mastodon

* Remove obsolete test fixture

* Replace occurrences of tootsuite/mastodon with mastodon/mastodon in CHANGELOG

And a few other places

* Fix anonymous access to outbox not being cached by the reverse proxy

Up until now, anonymous access to outbox was marked as public, but with a
0 duration for caching, which means remote proxies would only serve from cache
when the server was completely overwhelmed.

Changed that cache duration to one minute, so that repeated anonymous access
to one account's outbox can be appropriately cached.

Also added `Signature` to the `Vary` header in case a page is requested, so
that authenticated fetches are never served from cache (which only contains
public toots).

* Remove Vary: Accept header from webfinger controller

Indeed, we have stopped returning xrd, and only ever return jrd, so the
Accept request header does not matter anymore.

* Cache negative webfinger hits for 3 minutes

* Add tests

* Fix serialization of followers/following counts when user hides their network

Fixes #16382

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

Follow-up to #16510, forgot the controller exposing the actual followers…

* Add tests

* Fix some link previews being incorrectly generated from different prior links

PR #12403 added a cache to avoid redundant queries when the OEmbed endpoint can
be guessed from the URL. This caching mechanism is not perfectly correct as
there is no guarantee that all pages from a given domain share the same
OEmbed provider endpoint.

This PR prevents the FetchOEmbedService from caching OEmbed endpoint that
cannot be generalized by replacing a fully-qualified URL from the endpoint's
parameters, greatly reducing the number of incorrect cached generalizations.

* Add tests

* Fix scheduled statuses decreasing statuses counts

Fixes #16774

* Add tests

* Fix webauthn secure key authentication

Fixes #16769

Fixes #16699

Fixes #16602

* Add tests

* Add security-related tests

My first (unpublished) attempt at fixing the issues introduced (extremely
hard-to-exploit) security vulnerabilities, addressing them in a test.

* Fix authentication failures after going halfway through a sign-in attempt

* Refactor `authenticate_with_sign_in_token` and `authenticate_with_two_factor` to make the two authentication steps more obvious

* Add test

* Fix crash when encountering invalid account fields

If a status with a hashtag becomes very popular, it stands to
reason that the hashtag should have a chance at trending

Fix no stats being recorded for hashtags that are not allowed
to trend, and stop ignoring bots

Remove references to hashtags in profile directory from the code
and the admin UI

* Fix issues with POSIX::Spawn, Terrapin and Ruby 3.0

Also improve the Terrapin monkey-patch for the stderr/stdout issue.

* Fix keyword argument handling throughout the codebase

* Monkey-patch Paperclip to fix keyword arguments handling in validators

* Change validation_extensions to please CodeClimate

* Bump microformats from 4.2.1 to 4.3.1

* Allow Ruby 3.0

* Add Ruby 3.0 test target to CircleCI

* Add test for admin dashboard warnings

* Fix admin dashboard warnings on Ruby 3.0

Clicking the confirmation link multiple times currently leads to entering
account settings, which can be confusing. This commit changes that so that
it redirects to the root path, so it behaves the same way as clicking only
once in most cases.

* Add tests

* Ensure deleted statuses are marked as such

* Save some redis memory by not storing URIs in delete_upon_arrival values

* Avoid possible race condition when processing incoming Deletes

* Avoid potential duplicate Delete forwards

* Lower lock durations to reduce issues in case of hard crash of the Rails process

* Check for `lock.aquired?` and improve comment

* Refactor RedisLock usage in app/lib/activitypub

* Fix using incorrect or non-existent sender for relaying Deletes

Prevent new accounts from being created using the same underlying
e-mail as a suspended account using extensions and period
permutations. Stores e-mails as a SHA256 hash

Fix app scopes not being validated

With possible values `all`, `followed`, `follower`, and `none`,
control from whom notifications will generate a Web Push alert

Fix #15506

Raw SQL passed to `pluck` now has to be explicitly marked as SQL via
Arel.sql, see https://github.com/rails/rails/pull/27947

* Update devise-two-factor to unreleased fork for Rails 6 support

Update tests to match new `rotp` version.

* Update nsa gem to unreleased fork for Rails 6 support

* Update rails to 6.1.3 and rails-i18n to 6.0

* Update to unreleased fork of pluck_each for Ruby 6 support

* Run "rails app:update"

* Add missing ActiveStorage config file

* Use config.ssl_options instead of removed ApplicationController#force_ssl

Disabled force_ssl-related tests as they do not seem to be easily testable
anymore.

* Fix nonce directives by removing Rails 5 specific monkey-patching

* Fix fixture_file_upload deprecation warning

* Fix yield-based test failing with Rails 6

* Use Rails 6's index_with when possible

* Use ActiveRecord::Cache::Store#delete_multi from Rails 6

This will yield better performances when deleting an account

* Disable Rails 6.1's automatic preload link headers

Since Rails 6.1, ActionView adds preload links for javascript files
in the Links header per default.

In our case, that will bloat headers too much and potentially cause
issues with reverse proxies. Furhermore, we don't need those links,
as we already output them as HTML link tags.

* Switch to Rails 6.0 default config

* Switch to Rails 6.1 default config

* Do not include autoload paths in the load path

Fixes #5551

* Bypass MX validation for explicitly allowed domains

This spares some lookups and prevent issues in some edge cases with
local domains.

* Add tests

* Fix test

* Improve account counters handling

* Use ActiveRecord::Base::sanitize_sql to pass values instead of interpolating them

Keep using string interpolation for `key` as it is safe and using
“ActiveRecord::Base::sanitize_sql_hash_for_assignment” would require stitching
bits of SQL in a way that is not more easily checked for safety.

* Add migration hook to catch PostgreSQL versions earlier than 9.5