ENABLE_STARTTLS is designed to replace ENABLE_STARTTLS_AUTO by accepting
three values: 'auto' (the default), 'always', and 'never'. If
ENABLE_STARTTLS isn't provided, we fall back to ENABLE_STARTTLS_AUTO. In
this way, this change should be fully backwards compatible.

Resolves #20311

* Add tests

* Fix crash when trying to display orphaned action logs

* Add migration for older admin action logs

* Fix mastodon:setup not setting the admin's role properly

* Set contact username when creating admin account in mastodon:setup

* Fix typos

Found via `codespell -q 3 -S ./CHANGELOG.md,./AUTHORS.md,./config/locales,./app/javascript/mastodon/locales -L ba,keypair,medias,pixelx,ro`

* Follow-up typo fix

* Add model for custom filter keywords

* Use CustomFilterKeyword internally

Does not change the API

* Fix /filters/edit and /filters/new

* Add migration tests

* Remove whole_word column from custom_filters (covered by custom_filter_keywords)

* Redesign /filters

Instead of a list, present a card that displays more information and handles
multiple keywords per filter.

* Redesign /filters/new and /filters/edit to add and remove keywords

This adds a new gem dependency: cocoon, as well as a npm dependency:
cocoon-js-vanilla. Those are used to easily populate and remove form fields
from the user interface when manipulating multiple keyword filters at once.

* Add /api/v2/filters to edit filter with multiple keywords

Entities:
- `Filter`: `id`, `title`, `filter_action` (either `hide` or `warn`), `context`
  `keywords`
- `FilterKeyword`: `id`, `keyword`, `whole_word`

API endpoits:
- `GET /api/v2/filters` to list filters (including keywords)
- `POST /api/v2/filters` to create a new filter
  `keywords_attributes` can also be passed to create keywords in one request
- `GET /api/v2/filters/:id` to read a particular filter
- `PUT /api/v2/filters/:id` to update a new filter
  `keywords_attributes` can also be passed to edit, delete or add keywords in
   one request
- `DELETE /api/v2/filters/:id` to delete a particular filter
- `GET /api/v2/filters/:id/keywords` to list keywords for a filter
- `POST /api/v2/filters/:filter_id/keywords/:id` to add a new keyword to a
   filter
- `GET /api/v2/filter_keywords/:id` to read a particular keyword
- `PUT /api/v2/filter_keywords/:id` to edit a particular keyword
- `DELETE /api/v2/filter_keywords/:id` to delete a particular keyword

* Change from `irreversible` boolean to `action` enum

* Remove irrelevent `irreversible_must_be_within_context` check

* Fix /filters/new and /filters/edit with update for filter_action

* Fix Rubocop/Codeclimate complaining about task names

* Refactor FeedManager#phrase_filtered?

This moves regexp building and filter caching to the `CustomFilter` class.

This does not change the functional behavior yet, but this changes how the
cache is built, doing per-custom_filter regexps so that filters can be matched
independently, while still offering caching.

* Perform server-side filtering and output result in REST API

* Fix numerous filters_changed events being sent when editing multiple keywords at once

* Add some tests

* Use the new API in the WebUI

- use client-side logic for filters we have fetched rules for.
  This is so that filter changes can be retroactively applied without
  reloading the UI.
- use server-side logic for filters we haven't fetched rules for yet
  (e.g. network error, or initial timeline loading)

* Minor optimizations and refactoring

* Perform server-side filtering on the streaming server

* Change the wording of filter action labels

* Fix issues pointed out by linter

* Change design of “Show anyway” link in accordence to review comments

* Drop “irreversible” filtering behavior

* Move /api/v2/filter_keywords to /api/v1/filters/keywords

* Rename `filter_results` attribute to `filtered`

* Rename REST::LegacyFilterSerializer to REST::V1::FilterSerializer

* Fix systemChannelId value in streaming server

* Simplify code by removing client-side filtering code

The simplifcation comes at a cost though: filters aren't retroactively
applied anymore.

- Add rake task for generating Apple/Android icons and favicons from SVG
- Add rake task for generating PNG icons and logos for e-mails from SVG
- Remove obsolete Microsoft icons and configuration
- Remove PWA shortcut icons

Fixes #18342

* Add migration test about instance actor key

* Fix old migration

* Work around incorrect database state

* Fix null values being included in some indexes

* Update lib/mastodon/migration_helpers.rb

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

* Add documentation link to corruption error message

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

* Add migration tests for hide_network settings migration

* Add tests about suspended/suspended_at

* Add more tests regarding the results of migrations

* Fix migration test regarding stale conflicting remote account

* Add migration tests about AccountConversation

* Remove language detection through cld3

* Update app/helpers/languages_helper.rb

Co-authored-by: Yamagishi Kazutoshi <ykzts@desire.sh>

Co-authored-by: Yamagishi Kazutoshi <ykzts@desire.sh>

- populate the database with some data when testing migrations
- try both one-step and two-step migrations (`SKIP_POST_DEPLOYMENT_MIGRATIONS`)

Fixes #17297

* Add trending links

* Add overriding specific links trendability

* Add link type to preview cards and only trend articles

Change trends review notifications from being sent every 5 minutes to being sent every 2 hours

Change threshold from 5 unique accounts to 15 unique accounts

* Fix tests

Fix regression from #16896

In order to work around https://github.com/mastodon/mastodon/issues/16895,
add a warning to .env.production.sample, and change the mastodon:setup rake
task to:
- output a warning if a variable will be interpreted differently by dotenv
  and docker-compose
- ensure the printed config is compatible with docker-compose

* 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

occured -> occurred

* 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

It appears assets are built during image build, and they shouldn't need
to be rebuilt, since we now have reproducible builds.

* 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

* Fix external user creation failing when invite request text is required

Also fixes tootctl-based user creation.

* Add test about invites when invite request text is otherwise required

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

* Add tootctl maintenance fix-duplicates

This tool goes through the database to detect and fix duplicates.
This operation is very slow and may cause data loss (of data that would be
inaccessible without intervention because of the existing index corruptions).
It tries its best to make sensible decisions, and asks the user in some cases.

* Add warning message in db:migrate hook

* Clear Rails cache after being done with database deduplication

Avoids followers hash cache being incorrect, among other things

Fixes #14768

* Add emojis:generate_borders Rake task

* Address review

* Border all dark emoji

* Combine stroke with filter to reduce artifacting

* Cleanup Camera with Flash

* Add stroke-linejoin="round"

The previous filter and tweaks were effectively a poor imitation of it.
There are no artifacts for any dark emoji now!

* Set stroke-width using property

This fixes old versions of Firefox.

* Store emoji in string instead of array

* Use separate arguments for each path segment

* Remove "background: black;"

Fix a regression introduced in #13928, caused by TTY::Command building
shell commands by chaining string substitutions.

Ditch TTY::Command and use system instead (both do shell out).

When using one of the docker-compose containers, mastodon:setup will use the
existing .env.production rather than the generated one during the setup steps.

This is because dotenv does not overwrite env variables that are alreayd
defined, and the docker-compose.yml file loads the environment variables
from .env.production.

* Update Twemoji to 12.1.5

SVGs from Twemoji repo https://github.com/twitter/twemoji

* Update emoji_map.json to Unicode 12

* Add support for special characters in Redis passwords

Fixes #13154

* Refactor