Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Upstream README has been changed, but we have a completely different one.
  Kept our `README.md`.
- `lib/sanitize_ext/sanitize_config.rb`:
  Upstream added support for more incoming HTML tags (a large subset of what
  glitch-soc accepts).
  Change the code style to match upstream's but otherwise do not change our
  code.
- `spec/lib/sanitize_config_spec.rb`:
  Upstream added support for more incoming HTML tags (a large subset of what
  glitch-soc accepts).
  Kept our version, since the tests are mostly glitch-soc's, except for cases
  which are purposefuly different.

37 files changed, 319 insertions, 112 deletions

diff --git a/app/controllers/relationships_controller.rb b/app/controllers/relationships_controller.rb
index d40770726..52cf1e0c1 100644
--- a/app/controllers/relationships_controller.rb
+++ b/app/controllers/relationships_controller.rb
@@ -20,6 +20,8 @@ class RelationshipsController < ApplicationController
     @form.save
   rescue ActionController::ParameterMissing
     # Do nothing
+  rescue Mastodon::NotPermittedError, ActiveRecord::RecordNotFound
+    flash[:alert] = I18n.t('relationships.follow_failure') if action_from_button == 'follow'
   ensure
     redirect_to relationships_path(filter_params)
   end
@@ -61,8 +63,8 @@ class RelationshipsController < ApplicationController
       'unfollow'
     elsif params[:remove_from_followers]
       'remove_from_followers'
-    elsif params[:block_domains]
-      'block_domains'
+    elsif params[:block_domains] || params[:remove_domains_from_followers]
+      'remove_domains_from_followers'
     end
   end
 
diff --git a/app/javascript/mastodon/components/column_back_button.jsx b/app/javascript/mastodon/components/column_back_button.jsx
index 5bbf11652..5c5226b7e 100644
--- a/app/javascript/mastodon/components/column_back_button.jsx
+++ b/app/javascript/mastodon/components/column_back_button.jsx
@@ -15,10 +15,10 @@ export default class ColumnBackButton extends React.PureComponent {
   };
 
   handleClick = () => {
-    if (window.history && window.history.length === 1) {
-      this.context.router.history.push('/');
-    } else {
+    if (window.history && window.history.state) {
       this.context.router.history.goBack();
+    } else {
+      this.context.router.history.push('/');
     }
   };
 
diff --git a/app/javascript/mastodon/components/column_header.jsx b/app/javascript/mastodon/components/column_header.jsx
index 38f6ad60f..9ba783d90 100644
--- a/app/javascript/mastodon/components/column_header.jsx
+++ b/app/javascript/mastodon/components/column_header.jsx
@@ -43,14 +43,6 @@ class ColumnHeader extends React.PureComponent {
     animating: false,
   };
 
-  historyBack = () => {
-    if (window.history && window.history.length === 1) {
-      this.context.router.history.push('/');
-    } else {
-      this.context.router.history.goBack();
-    }
-  };
-
   handleToggleClick = (e) => {
     e.stopPropagation();
     this.setState({ collapsed: !this.state.collapsed, animating: true });
@@ -69,7 +61,11 @@ class ColumnHeader extends React.PureComponent {
   };
 
   handleBackClick = () => {
-    this.historyBack();
+    if (window.history && window.history.state) {
+      this.context.router.history.goBack();
+    } else {
+      this.context.router.history.push('/');
+    }
   };
 
   handleTransitionEnd = () => {
diff --git a/app/javascript/mastodon/components/status_content.jsx b/app/javascript/mastodon/components/status_content.jsx
index a1c38171f..f9c9fe079 100644
--- a/app/javascript/mastodon/components/status_content.jsx
+++ b/app/javascript/mastodon/components/status_content.jsx
@@ -6,7 +6,7 @@ import { Link } from 'react-router-dom';
 import classnames from 'classnames';
 import PollContainer from 'mastodon/containers/poll_container';
 import Icon from 'mastodon/components/icon';
-import { autoPlayGif, languages as preloadedLanguages, translationEnabled } from 'mastodon/initial_state';
+import { autoPlayGif, languages as preloadedLanguages } from 'mastodon/initial_state';
 
 const MAX_HEIGHT = 706; // 22px * 32 (+ 2px padding at the top)
 
@@ -220,7 +220,7 @@ class StatusContent extends React.PureComponent {
 
     const hidden = this.props.onExpandedToggle ? !this.props.expanded : this.state.hidden;
     const renderReadMore = this.props.onClick && status.get('collapsed');
-    const renderTranslate = translationEnabled && this.context.identity.signedIn && this.props.onTranslate && ['public', 'unlisted'].includes(status.get('visibility')) && status.get('contentHtml').length > 0 && status.get('language') !== null && intl.locale !== status.get('language');
+    const renderTranslate = this.props.onTranslate && status.get('translatable');
 
     const content = { __html: status.get('translation') ? status.getIn(['translation', 'content']) : status.get('contentHtml') };
     const spoilerContent = { __html: status.get('spoilerHtml') };
diff --git a/app/javascript/mastodon/features/ui/components/header.jsx b/app/javascript/mastodon/features/ui/components/header.jsx
index 1384bebda..92adc47a9 100644
--- a/app/javascript/mastodon/features/ui/components/header.jsx
+++ b/app/javascript/mastodon/features/ui/components/header.jsx
@@ -22,8 +22,8 @@ const mapDispatchToProps = (dispatch) => ({
   },
 });
 
-export default @connect(null, mapDispatchToProps)
-@withRouter
+export default @withRouter
+@connect(null, mapDispatchToProps)
 class Header extends React.PureComponent {
 
   static contextTypes = {
diff --git a/app/javascript/mastodon/features/ui/components/navigation_panel.jsx b/app/javascript/mastodon/features/ui/components/navigation_panel.jsx
index 9a9309be0..755b19349 100644
--- a/app/javascript/mastodon/features/ui/components/navigation_panel.jsx
+++ b/app/javascript/mastodon/features/ui/components/navigation_panel.jsx
@@ -82,8 +82,8 @@ class NavigationPanel extends React.Component {
         {signedIn && (
           <React.Fragment>
             <ColumnLink transparent to='/conversations' icon='at' text={intl.formatMessage(messages.direct)} />
-            <ColumnLink transparent to='/favourites' icon='star' text={intl.formatMessage(messages.favourites)} />
             <ColumnLink transparent to='/bookmarks' icon='bookmark' text={intl.formatMessage(messages.bookmarks)} />
+            <ColumnLink transparent to='/favourites' icon='star' text={intl.formatMessage(messages.favourites)} />
             <ColumnLink transparent to='/lists' icon='list-ul' text={intl.formatMessage(messages.lists)} />
 
             <ListPanel />
diff --git a/app/javascript/mastodon/features/ui/index.jsx b/app/javascript/mastodon/features/ui/index.jsx
index 4f0ea0450..2dd59f95d 100644
--- a/app/javascript/mastodon/features/ui/index.jsx
+++ b/app/javascript/mastodon/features/ui/index.jsx
@@ -474,10 +474,10 @@ class UI extends React.PureComponent {
   };
 
   handleHotkeyBack = () => {
-    if (window.history && window.history.length === 1) {
-      this.context.router.history.push('/');
-    } else {
+    if (window.history && window.history.state) {
       this.context.router.history.goBack();
+    } else {
+      this.context.router.history.push('/');
     }
   };
 
diff --git a/app/javascript/mastodon/initial_state.js b/app/javascript/mastodon/initial_state.js
index c9c3a7647..cab7f1f6b 100644
--- a/app/javascript/mastodon/initial_state.js
+++ b/app/javascript/mastodon/initial_state.js
@@ -80,7 +80,6 @@
  * @property {boolean} use_blurhash
  * @property {boolean=} use_pending_items
  * @property {string} version
- * @property {boolean} translation_enabled
  */
 
 /**
@@ -132,7 +131,6 @@ export const unfollowModal = getMeta('unfollow_modal');
 export const useBlurhash = getMeta('use_blurhash');
 export const usePendingItems = getMeta('use_pending_items');
 export const version = getMeta('version');
-export const translationEnabled = getMeta('translation_enabled');
 export const languages = initialState?.languages;
 export const statusPageUrl = getMeta('status_page_url');
 
diff --git a/app/javascript/styles/application.scss b/app/javascript/styles/application.scss
index 81a040108..1b2969c23 100644
--- a/app/javascript/styles/application.scss
+++ b/app/javascript/styles/application.scss
@@ -23,3 +23,4 @@
 @import 'mastodon/dashboard';
 @import 'mastodon/rtl';
 @import 'mastodon/accessibility';
+@import 'mastodon/rich_text';
diff --git a/app/javascript/styles/mastodon/rich_text.scss b/app/javascript/styles/mastodon/rich_text.scss
new file mode 100644
index 000000000..35901984b
--- /dev/null
+++ b/app/javascript/styles/mastodon/rich_text.scss
@@ -0,0 +1,64 @@
+.status__content__text,
+.e-content,
+.reply-indicator__content {
+  pre,
+  blockquote {
+    margin-bottom: 20px;
+    white-space: pre-wrap;
+    unicode-bidi: plaintext;
+
+    &:last-child {
+      margin-bottom: 0;
+    }
+  }
+
+  blockquote {
+    padding-left: 10px;
+    border-left: 3px solid $darker-text-color;
+    color: $darker-text-color;
+    white-space: normal;
+
+    p:last-child {
+      margin-bottom: 0;
+    }
+  }
+
+  & > ul,
+  & > ol {
+    margin-bottom: 20px;
+  }
+
+  b,
+  strong {
+    font-weight: 700;
+  }
+
+  em,
+  i {
+    font-style: italic;
+  }
+
+  ul,
+  ol {
+    margin-left: 2em;
+
+    p {
+      margin: 0;
+    }
+  }
+
+  ul {
+    list-style-type: disc;
+  }
+
+  ol {
+    list-style-type: decimal;
+  }
+}
+
+.reply-indicator__content {
+  blockquote {
+    border-left-color: $inverted-text-color;
+    color: $inverted-text-color;
+  }
+}
diff --git a/app/lib/feed_manager.rb b/app/lib/feed_manager.rb
index be5b68b3f..4ce888fc9 100644
--- a/app/lib/feed_manager.rb
+++ b/app/lib/feed_manager.rb
@@ -322,27 +322,27 @@ class FeedManager
   def clean_feeds!(type, ids)
     reblogged_id_sets = {}
 
-    redis.pipelined do
+    redis.pipelined do |pipeline|
       ids.each do |feed_id|
-        redis.del(key(type, feed_id))
         reblog_key = key(type, feed_id, 'reblogs')
         # We collect a future for this: we don't block while getting
         # it, but we can iterate over it later.
-        reblogged_id_sets[feed_id] = redis.zrange(reblog_key, 0, -1)
-        redis.del(reblog_key)
+        reblogged_id_sets[feed_id] = pipeline.zrange(reblog_key, 0, -1)
+        pipeline.del(key(type, feed_id), reblog_key)
       end
     end
 
     # Remove all of the reblog tracking keys we just removed the
     # references to.
-    redis.pipelined do
-      reblogged_id_sets.each do |feed_id, future|
-        future.value.each do |reblogged_id|
-          reblog_set_key = key(type, feed_id, "reblogs:#{reblogged_id}")
-          redis.del(reblog_set_key)
-        end
+    keys_to_delete = reblogged_id_sets.flat_map do |feed_id, future|
+      future.value.map do |reblogged_id|
+        key(type, feed_id, "reblogs:#{reblogged_id}")
       end
     end
+
+    redis.del(keys_to_delete) unless keys_to_delete.empty?
+
+    nil
   end
 
   private
diff --git a/app/lib/translation_service.rb b/app/lib/translation_service.rb
index 285f30939..5ff93674a 100644
--- a/app/lib/translation_service.rb
+++ b/app/lib/translation_service.rb
@@ -21,6 +21,10 @@ class TranslationService
     ENV['DEEPL_API_KEY'].present? || ENV['LIBRE_TRANSLATE_ENDPOINT'].present?
   end
 
+  def supported?(_source_language, _target_language)
+    false
+  end
+
   def translate(_text, _source_language, _target_language)
     raise NotImplementedError
   end
diff --git a/app/lib/translation_service/deepl.rb b/app/lib/translation_service/deepl.rb
index 151d33d90..deff95a1d 100644
--- a/app/lib/translation_service/deepl.rb
+++ b/app/lib/translation_service/deepl.rb
@@ -11,33 +11,53 @@ class TranslationService::DeepL < TranslationService
   end
 
   def translate(text, source_language, target_language)
-    request(text, source_language, target_language).perform do |res|
+    form = { text: text, source_lang: source_language&.upcase, target_lang: target_language, tag_handling: 'html' }
+    request(:post, '/v2/translate', form: form) do |res|
+      transform_response(res.body_with_limit)
+    end
+  end
+
+  def supported?(source_language, target_language)
+    source_language.in?(languages('source')) && target_language.in?(languages('target'))
+  end
+
+  private
+
+  def languages(type)
+    Rails.cache.fetch("translation_service/deepl/languages/#{type}", expires_in: 7.days, race_condition_ttl: 1.minute) do
+      request(:get, "/v2/languages?type=#{type}") do |res|
+        # In DeepL, EN and PT are deprecated in favor of EN-GB/EN-US and PT-BR/PT-PT, so
+        # they are supported but not returned by the API.
+        extra = type == 'source' ? [nil] : %w(en pt)
+        languages = Oj.load(res.body_with_limit).map { |language| language['language'].downcase }
+
+        languages + extra
+      end
+    end
+  end
+
+  def request(verb, path, **options)
+    req = Request.new(verb, "#{base_url}#{path}", **options)
+    req.add_headers(Authorization: "DeepL-Auth-Key #{@api_key}")
+    req.perform do |res|
       case res.code
       when 429
         raise TooManyRequestsError
       when 456
         raise QuotaExceededError
       when 200...300
-        transform_response(res.body_with_limit)
+        yield res
       else
         raise UnexpectedResponseError
       end
     end
   end
 
-  private
-
-  def request(text, source_language, target_language)
-    req = Request.new(:post, endpoint_url, form: { text: text, source_lang: source_language&.upcase, target_lang: target_language, tag_handling: 'html' })
-    req.add_headers(Authorization: "DeepL-Auth-Key #{@api_key}")
-    req
-  end
-
-  def endpoint_url
+  def base_url
     if @plan == 'free'
-      'https://api-free.deepl.com/v2/translate'
+      'https://api-free.deepl.com'
     else
-      'https://api.deepl.com/v2/translate'
+      'https://api.deepl.com'
     end
   end
 
diff --git a/app/lib/translation_service/libre_translate.rb b/app/lib/translation_service/libre_translate.rb
index 4ebe21e45..743e4d77f 100644
--- a/app/lib/translation_service/libre_translate.rb
+++ b/app/lib/translation_service/libre_translate.rb
@@ -9,29 +9,45 @@ class TranslationService::LibreTranslate < TranslationService
   end
 
   def translate(text, source_language, target_language)
-    request(text, source_language, target_language).perform do |res|
+    body = Oj.dump(q: text, source: source_language.presence || 'auto', target: target_language, format: 'html', api_key: @api_key)
+    request(:post, '/translate', body: body) do |res|
+      transform_response(res.body_with_limit, source_language)
+    end
+  end
+
+  def supported?(source_language, target_language)
+    languages.key?(source_language) && languages[source_language].include?(target_language)
+  end
+
+  private
+
+  def languages
+    Rails.cache.fetch('translation_service/libre_translate/languages', expires_in: 7.days, race_condition_ttl: 1.minute) do
+      request(:get, '/languages') do |res|
+        languages = Oj.load(res.body_with_limit).to_h { |language| [language['code'], language['targets']] }
+        languages[nil] = languages.values.flatten.uniq
+        languages
+      end
+    end
+  end
+
+  def request(verb, path, **options)
+    req = Request.new(verb, "#{@base_url}#{path}", allow_local: true, **options)
+    req.add_headers('Content-Type': 'application/json')
+    req.perform do |res|
       case res.code
       when 429
         raise TooManyRequestsError
       when 403
         raise QuotaExceededError
       when 200...300
-        transform_response(res.body_with_limit, source_language)
+        yield res
       else
         raise UnexpectedResponseError
       end
     end
   end
 
-  private
-
-  def request(text, source_language, target_language)
-    body = Oj.dump(q: text, source: source_language.presence || 'auto', target: target_language, format: 'html', api_key: @api_key)
-    req = Request.new(:post, "#{@base_url}/translate", body: body, allow_local: true)
-    req.add_headers('Content-Type': 'application/json')
-    req
-  end
-
   def transform_response(str, source_language)
     json = Oj.load(str, mode: :strict)
 
diff --git a/app/mailers/application_mailer.rb b/app/mailers/application_mailer.rb
index 73b623576..35f0b5fee 100644
--- a/app/mailers/application_mailer.rb
+++ b/app/mailers/application_mailer.rb
@@ -7,9 +7,17 @@ class ApplicationMailer < ActionMailer::Base
   helper :instance
   helper :formatting
 
+  after_action :set_autoreply_headers!
+
   protected
 
   def locale_for_account(account, &block)
     I18n.with_locale(account.user_locale || I18n.default_locale, &block)
   end
+
+  def set_autoreply_headers!
+    headers['Precedence'] = 'list'
+    headers['X-Auto-Response-Suppress'] = 'All'
+    headers['Auto-Submitted'] = 'auto-generated'
+  end
 end
diff --git a/app/models/concerns/omniauthable.rb b/app/models/concerns/omniauthable.rb
index b0aa5be6f..41eae215b 100644
--- a/app/models/concerns/omniauthable.rb
+++ b/app/models/concerns/omniauthable.rb
@@ -61,7 +61,7 @@ module Omniauthable
         user.account.avatar_remote_url = nil
       end
 
-      user.skip_confirmation! if email_is_verified
+      user.confirm! if email_is_verified
       user.save!
       user
     end
diff --git a/app/models/follow_recommendation_suppression.rb b/app/models/follow_recommendation_suppression.rb
index a9dbbfc18..e261a2fe3 100644
--- a/app/models/follow_recommendation_suppression.rb
+++ b/app/models/follow_recommendation_suppression.rb
@@ -20,9 +20,9 @@ class FollowRecommendationSuppression < ApplicationRecord
   private
 
   def remove_follow_recommendations
-    redis.pipelined do
+    redis.pipelined do |pipeline|
       I18n.available_locales.each do |locale|
-        redis.zrem("follow_recommendations:#{locale}", account_id)
+        pipeline.zrem("follow_recommendations:#{locale}", account_id)
       end
     end
   end
diff --git a/app/models/form/account_batch.rb b/app/models/form/account_batch.rb
index 473622edf..6a05f8163 100644
--- a/app/models/form/account_batch.rb
+++ b/app/models/form/account_batch.rb
@@ -17,8 +17,8 @@ class Form::AccountBatch
       unfollow!
     when 'remove_from_followers'
       remove_from_followers!
-    when 'block_domains'
-      block_domains!
+    when 'remove_domains_from_followers'
+      remove_domains_from_followers!
     when 'approve'
       approve!
     when 'reject'
@@ -35,9 +35,15 @@ class Form::AccountBatch
   private
 
   def follow!
+    error = nil
+
     accounts.each do |target_account|
       FollowService.new.call(current_account, target_account)
+    rescue Mastodon::NotPermittedError, ActiveRecord::RecordNotFound => e
+      error ||= e
     end
+
+    raise error if error.present?
   end
 
   def unfollow!
@@ -50,10 +56,8 @@ class Form::AccountBatch
     RemoveFromFollowersService.new.call(current_account, account_ids)
   end
 
-  def block_domains!
-    AfterAccountDomainBlockWorker.push_bulk(account_domains) do |domain|
-      [current_account.id, domain]
-    end
+  def remove_domains_from_followers!
+    RemoveDomainsFromFollowersService.new.call(current_account, account_domains)
   end
 
   def account_domains
diff --git a/app/models/status.rb b/app/models/status.rb
index bf102120e..d053dea44 100644
--- a/app/models/status.rb
+++ b/app/models/status.rb
@@ -237,6 +237,16 @@ class Status < ApplicationRecord
     public_visibility? || unlisted_visibility?
   end
 
+  def translatable?
+    translate_target_locale = I18n.locale.to_s.split(/[_-]/).first
+
+    distributable? &&
+      content.present? &&
+      language != translate_target_locale &&
+      TranslationService.configured? &&
+      TranslationService.configured.supported?(language, translate_target_locale)
+  end
+
   alias sign? distributable?
 
   def with_media?
diff --git a/app/serializers/initial_state_serializer.rb b/app/serializers/initial_state_serializer.rb
index 2cac42e8d..45ee06e12 100644
--- a/app/serializers/initial_state_serializer.rb
+++ b/app/serializers/initial_state_serializer.rb
@@ -44,7 +44,6 @@ class InitialStateSerializer < ActiveModel::Serializer
       timeline_preview: Setting.timeline_preview,
       activity_api_enabled: Setting.activity_api_enabled,
       single_user_mode: Rails.configuration.x.single_user_mode,
-      translation_enabled: TranslationService.configured?,
       trends_as_landing_page: Setting.trends_as_landing_page,
       status_page_url: Setting.status_page_url,
     }
diff --git a/app/serializers/rest/status_serializer.rb b/app/serializers/rest/status_serializer.rb
index 659c45b83..ce08b6db8 100644
--- a/app/serializers/rest/status_serializer.rb
+++ b/app/serializers/rest/status_serializer.rb
@@ -4,7 +4,7 @@ class REST::StatusSerializer < ActiveModel::Serializer
   include FormattingHelper
 
   attributes :id, :created_at, :in_reply_to_id, :in_reply_to_account_id,
-             :sensitive, :spoiler_text, :visibility, :language,
+             :sensitive, :spoiler_text, :visibility, :language, :translatable,
              :uri, :url, :replies_count, :reblogs_count,
              :favourites_count, :edited_at
 
@@ -52,6 +52,10 @@ class REST::StatusSerializer < ActiveModel::Serializer
     object.account.user_shows_application? || (current_user? && current_user.account_id == object.account_id)
   end
 
+  def translatable
+    current_user? && object.translatable?
+  end
+
   def visibility
     # This visibility is masked behind "private"
     # to avoid API changes because there are no
diff --git a/app/services/batched_remove_status_service.rb b/app/services/batched_remove_status_service.rb
index e2c370057..a48386ba2 100644
--- a/app/services/batched_remove_status_service.rb
+++ b/app/services/batched_remove_status_service.rb
@@ -48,9 +48,9 @@ class BatchedRemoveStatusService < BaseService
 
     # Cannot be batched
     @status_id_cutoff = Mastodon::Snowflake.id_at(2.weeks.ago)
-    redis.pipelined do
+    redis.pipelined do |pipeline|
       statuses.each do |status|
-        unpush_from_public_timelines(status)
+        unpush_from_public_timelines(status, pipeline)
       end
     end
   end
@@ -73,22 +73,22 @@ class BatchedRemoveStatusService < BaseService
     end
   end
 
-  def unpush_from_public_timelines(status)
+  def unpush_from_public_timelines(status, pipeline)
     return unless status.public_visibility? && status.id > @status_id_cutoff
 
     payload = Oj.dump(event: :delete, payload: status.id.to_s)
 
-    redis.publish('timeline:public', payload)
-    redis.publish(status.local? ? 'timeline:public:local' : 'timeline:public:remote', payload)
+    pipeline.publish('timeline:public', payload)
+    pipeline.publish(status.local? ? 'timeline:public:local' : 'timeline:public:remote', payload)
 
     if status.media_attachments.any?
-      redis.publish('timeline:public:media', payload)
-      redis.publish(status.local? ? 'timeline:public:local:media' : 'timeline:public:remote:media', payload)
+      pipeline.publish('timeline:public:media', payload)
+      pipeline.publish(status.local? ? 'timeline:public:local:media' : 'timeline:public:remote:media', payload)
     end
 
     status.tags.map { |tag| tag.name.mb_chars.downcase }.each do |hashtag|
-      redis.publish("timeline:hashtag:#{hashtag}", payload)
-      redis.publish("timeline:hashtag:#{hashtag}:local", payload) if status.local?
+      pipeline.publish("timeline:hashtag:#{hashtag}", payload)
+      pipeline.publish("timeline:hashtag:#{hashtag}:local", payload) if status.local?
     end
   end
 
diff --git a/app/services/follow_migration_service.rb b/app/services/follow_migration_service.rb
new file mode 100644
index 000000000..cfe9093cb
--- /dev/null
+++ b/app/services/follow_migration_service.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+class FollowMigrationService < FollowService
+  # Follow an account with the same settings as another account, and unfollow the old account once the request is sent
+  # @param [Account] source_account From which to follow
+  # @param [Account] target_account Account to follow
+  # @param [Account] old_target_account Account to unfollow once the follow request has been sent to the new one
+  # @option [Boolean] bypass_locked Whether to immediately follow the new account even if it is locked
+  def call(source_account, target_account, old_target_account, bypass_locked: false)
+    @old_target_account = old_target_account
+
+    follow    = source_account.active_relationships.find_by(target_account: old_target_account)
+    reblogs   = follow&.show_reblogs?
+    notify    = follow&.notify?
+    languages = follow&.languages
+
+    super(source_account, target_account, reblogs: reblogs, notify: notify, languages: languages, bypass_locked: bypass_locked, bypass_limit: true)
+  end
+
+  private
+
+  def request_follow!
+    follow_request = @source_account.request_follow!(@target_account, **follow_options.merge(rate_limit: @options[:with_rate_limit], bypass_limit: @options[:bypass_limit]))
+
+    if @target_account.local?
+      LocalNotificationWorker.perform_async(@target_account.id, follow_request.id, follow_request.class.name, 'follow_request')
+      UnfollowService.new.call(@source_account, @old_target_account, skip_unmerge: true)
+    elsif @target_account.activitypub?
+      ActivityPub::MigratedFollowDeliveryWorker.perform_async(build_json(follow_request), @source_account.id, @target_account.inbox_url, @old_target_account.id)
+    end
+
+    follow_request
+  end
+
+  def direct_follow!
+    follow = super
+    UnfollowService.new.call(@source_account, @old_target_account, skip_unmerge: true)
+    follow
+  end
+end
diff --git a/app/services/remove_domains_from_followers_service.rb b/app/services/remove_domains_from_followers_service.rb
new file mode 100644
index 000000000..d76763409
--- /dev/null
+++ b/app/services/remove_domains_from_followers_service.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class RemoveDomainsFromFollowersService < BaseService
+  include Payloadable
+
+  def call(source_account, target_domains)
+    source_account.passive_relationships.where(account_id: Account.where(domain: target_domains)).find_each do |follow|
+      follow.destroy
+
+      create_notification(follow) if source_account.local? && !follow.account.local? && follow.account.activitypub?
+    end
+  end
+
+  private
+
+  def create_notification(follow)
+    ActivityPub::DeliveryWorker.perform_async(build_json(follow), follow.target_account_id, follow.account.inbox_url)
+  end
+
+  def build_json(follow)
+    Oj.dump(serialize_payload(follow, ActivityPub::RejectFollowSerializer))
+  end
+end
diff --git a/app/services/translate_status_service.rb b/app/services/translate_status_service.rb
index 539a0d9db..92d8b62a0 100644
--- a/app/services/translate_status_service.rb
+++ b/app/services/translate_status_service.rb
@@ -6,7 +6,7 @@ class TranslateStatusService < BaseService
   include FormattingHelper
 
   def call(status, target_language)
-    raise Mastodon::NotPermittedError unless status.public_visibility? || status.unlisted_visibility?
+    raise Mastodon::NotPermittedError unless status.translatable?
 
     @status = status
     @content = status_content_format(@status)
diff --git a/app/validators/ed25519_key_validator.rb b/app/validators/ed25519_key_validator.rb
index 00a448d5a..adf49296b 100644
--- a/app/validators/ed25519_key_validator.rb
+++ b/app/validators/ed25519_key_validator.rb
@@ -6,7 +6,7 @@ class Ed25519KeyValidator < ActiveModel::EachValidator
 
     key = Base64.decode64(value)
 
-    record.errors[attribute] << I18n.t('crypto.errors.invalid_key') unless verified?(key)
+    record.errors.add(attribute, I18n.t('crypto.errors.invalid_key')) unless verified?(key)
   end
 
   private
diff --git a/app/validators/ed25519_signature_validator.rb b/app/validators/ed25519_signature_validator.rb
index 77a21b837..0e74c231e 100644
--- a/app/validators/ed25519_signature_validator.rb
+++ b/app/validators/ed25519_signature_validator.rb
@@ -8,7 +8,7 @@ class Ed25519SignatureValidator < ActiveModel::EachValidator
     signature  = Base64.decode64(value)
     message    = option_to_value(record, :message)
 
-    record.errors[attribute] << I18n.t('crypto.errors.invalid_signature') unless verified?(verify_key, signature, message)
+    record.errors.add(attribute, I18n.t('crypto.errors.invalid_signature')) unless verified?(verify_key, signature, message)
   end
 
   private
diff --git a/app/views/accounts/show.rss.ruby b/app/views/accounts/show.rss.ruby
index 34e29d483..7a77511ce 100644
--- a/app/views/accounts/show.rss.ruby
+++ b/app/views/accounts/show.rss.ruby
@@ -5,7 +5,7 @@ RSS::Builder.build do |doc|
   doc.image(full_asset_url(@account.avatar.url(:original)), display_name(@account), params[:tag].present? ? short_account_tag_url(@account, params[:tag]) : short_account_url(@account))
   doc.last_build_date(@statuses.first.created_at) if @statuses.any?
   doc.icon(full_asset_url(@account.avatar.url(:original)))
-  doc.generator("Mastodon v#{Mastodon::Version.to_s}")
+  doc.generator("Mastodon v#{Mastodon::Version}")
 
   @statuses.each do |status|
     doc.item do |item|
@@ -18,12 +18,12 @@ RSS::Builder.build do |doc|
         item.enclosure(full_asset_url(media.file.url(:original, false)), media.file.content_type, media.file.size)
       end
 
-      status.ordered_media_attachments.each do |media|
-        item.media_content(full_asset_url(media.file.url(:original, false)), media.file.content_type, media.file.size) do |media_content|
-          media_content.medium(media.gifv? ? 'image' : media.type.to_s)
+      status.ordered_media_attachments.each do |media_attachment|
+        item.media_content(full_asset_url(media_attachment.file.url(:original, false)), media_attachment.file.content_type, media_attachment.file.size) do |media_content|
+          media_content.medium(media_attachment.gifv? ? 'image' : media_attachment.type.to_s)
           media_content.rating(status.sensitive? ? 'adult' : 'nonadult')
-          media_content.description(media.description) if media.description.present?
-          media_content.thumbnail(media.thumbnail.url(:original, false)) if media.thumbnail?
+          media_content.description(media_attachment.description) if media_attachment.description.present?
+          media_content.thumbnail(media_attachment.thumbnail.url(:original, false)) if media_attachment.thumbnail?
         end
       end
 
diff --git a/app/views/admin/statuses/show.html.haml b/app/views/admin/statuses/show.html.haml
index 1e1e63f37..e070e5872 100644
--- a/app/views/admin/statuses/show.html.haml
+++ b/app/views/admin/statuses/show.html.haml
@@ -31,7 +31,7 @@
           %td
             - if @status.trend.allowed?
               %abbr{ title: t('admin.trends.tags.current_score', score: @status.trend.score) }= t('admin.trends.tags.trending_rank', rank: @status.trend.rank)
-            - elsif @status.trend.requires_review?
+            - elsif @status.requires_review?
               = t('admin.trends.pending_review')
             - else
               = t('admin.trends.not_allowed_to_trend')
diff --git a/app/views/relationships/show.html.haml b/app/views/relationships/show.html.haml
index e1ead6945..fcda6317e 100644
--- a/app/views/relationships/show.html.haml
+++ b/app/views/relationships/show.html.haml
@@ -45,7 +45,7 @@
 
         = f.button safe_join([fa_icon('trash'), t('relationships.remove_selected_followers')]), name: :remove_from_followers, class: 'table-action-link', type: :submit, data: { confirm: t('relationships.confirm_remove_selected_followers') } unless following_relationship?
 
-        = f.button safe_join([fa_icon('trash'), t('relationships.remove_selected_domains')]), name: :block_domains, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') } if followed_by_relationship?
+        = f.button safe_join([fa_icon('trash'), t('relationships.remove_selected_domains')]), name: :remove_domains_from_followers, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') } if followed_by_relationship?
     .batch-table__body
       - if @accounts.empty?
         = nothing_here 'nothing-here--under-tabs'
diff --git a/app/views/tags/show.rss.ruby b/app/views/tags/show.rss.ruby
index 8e0c2327b..bbda1ad4b 100644
--- a/app/views/tags/show.rss.ruby
+++ b/app/views/tags/show.rss.ruby
@@ -3,7 +3,7 @@ RSS::Builder.build do |doc|
   doc.description(I18n.t('rss.descriptions.tag', hashtag: @tag.display_name))
   doc.link(tag_url(@tag))
   doc.last_build_date(@statuses.first.created_at) if @statuses.any?
-  doc.generator("Mastodon v#{Mastodon::Version.to_s}")
+  doc.generator("Mastodon v#{Mastodon::Version}")
 
   @statuses.each do |status|
     doc.item do |item|
@@ -16,12 +16,12 @@ RSS::Builder.build do |doc|
         item.enclosure(full_asset_url(media.file.url(:original, false)), media.file.content_type, media.file.size)
       end
 
-      status.ordered_media_attachments.each do |media|
-        item.media_content(full_asset_url(media.file.url(:original, false)), media.file.content_type, media.file.size) do |media_content|
-          media_content.medium(media.gifv? ? 'image' : media.type.to_s)
+      status.ordered_media_attachments.each do |media_attachment|
+        item.media_content(full_asset_url(media_attachment.file.url(:original, false)), media_attachment.file.content_type, media_attachment.file.size) do |media_content|
+          media_content.medium(media_attachment.gifv? ? 'image' : media_attachment.type.to_s)
           media_content.rating(status.sensitive? ? 'adult' : 'nonadult')
-          media_content.description(media.description) if media.description.present?
-          media_content.thumbnail(media.thumbnail.url(:original, false)) if media.thumbnail?
+          media_content.description(media_attachment.description) if media_attachment.description.present?
+          media_content.thumbnail(media_attachment.thumbnail.url(:original, false)) if media_attachment.thumbnail?
         end
       end
 
diff --git a/app/views/user_mailer/appeal_rejected.html.haml b/app/views/user_mailer/appeal_rejected.html.haml
index 75cd9d023..c316a73fb 100644
--- a/app/views/user_mailer/appeal_rejected.html.haml
+++ b/app/views/user_mailer/appeal_rejected.html.haml
@@ -17,7 +17,7 @@
                                 %tbody
                                   %tr
                                     %td
-                                      = image_tag full_pack_url('media/images/mailer/icon_warning.png'), alt: ''
+                                      = image_tag full_pack_url('media/images/mailer/icon_flag.png'), alt: ''
 
                               %h1= t 'user_mailer.appeal_rejected.title'
 
diff --git a/app/views/well_known/host_meta/show.xml.ruby b/app/views/well_known/host_meta/show.xml.ruby
index b4e867c5f..bb5a01a1b 100644
--- a/app/views/well_known/host_meta/show.xml.ruby
+++ b/app/views/well_known/host_meta/show.xml.ruby
@@ -9,4 +9,4 @@ doc << Ox::Element.new('XRD').tap do |xrd|
   end
 end
 
-('<?xml version="1.0" encoding="UTF-8"?>' + Ox.dump(doc, effort: :tolerant)).force_encoding('UTF-8')
+"<?xml version=\"1.0\" encoding=\"UTF-8\"?>#{Ox.dump(doc, effort: :tolerant)}".force_encoding('UTF-8')
diff --git a/app/workers/activitypub/delivery_worker.rb b/app/workers/activitypub/delivery_worker.rb
index d9153132b..7c1c14766 100644
--- a/app/workers/activitypub/delivery_worker.rb
+++ b/app/workers/activitypub/delivery_worker.rb
@@ -10,6 +10,16 @@ class ActivityPub::DeliveryWorker
 
   sidekiq_options queue: 'push', retry: 16, dead: false
 
+  # Unfortunately, we cannot control Sidekiq's jitter, so add our own
+  sidekiq_retry_in do |count|
+    # This is Sidekiq's default delay
+    delay  = (count**4) + 15
+    # Our custom jitter, that will be added to Sidekiq's built-in one.
+    # Sidekiq's built-in jitter is `rand(10) * (count + 1)`
+    jitter = rand(0.5 * (count**4))
+    delay + jitter
+  end
+
   HEADERS = { 'Content-Type' => 'application/activity+json' }.freeze
 
   def perform(json, source_account_id, inbox_url, options = {})
diff --git a/app/workers/activitypub/migrated_follow_delivery_worker.rb b/app/workers/activitypub/migrated_follow_delivery_worker.rb
new file mode 100644
index 000000000..daf30e0ae
--- /dev/null
+++ b/app/workers/activitypub/migrated_follow_delivery_worker.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class ActivityPub::MigratedFollowDeliveryWorker < ActivityPub::DeliveryWorker
+  def perform(json, source_account_id, inbox_url, old_target_account_id, options = {})
+    super(json, source_account_id, inbox_url, options)
+    unfollow_old_account!(old_target_account_id)
+  end
+
+  private
+
+  def unfollow_old_account!(old_target_account_id)
+    old_target_account = Account.find(old_target_account_id)
+    UnfollowService.new.call(@source_account, old_target_account, skip_unmerge: true)
+  rescue
+    true
+  end
+end
diff --git a/app/workers/scheduler/follow_recommendations_scheduler.rb b/app/workers/scheduler/follow_recommendations_scheduler.rb
index 04008a9d9..17cf3f2cc 100644
--- a/app/workers/scheduler/follow_recommendations_scheduler.rb
+++ b/app/workers/scheduler/follow_recommendations_scheduler.rb
@@ -20,7 +20,7 @@ class Scheduler::FollowRecommendationsScheduler
 
     Trends.available_locales.each do |locale|
       recommendations = if AccountSummary.safe.filtered.localized(locale).exists? # We can skip the work if no accounts with that language exist
-                          FollowRecommendation.localized(locale).order(rank: :desc).limit(SET_SIZE).map { |recommendation| [recommendation.account_id, recommendation.rank] }
+                          FollowRecommendation.localized(locale).order(rank: :desc).limit(SET_SIZE).map { |recommendation| [recommendation.rank, recommendation.account_id] }
                         else
                           []
                         end
@@ -33,14 +33,14 @@ class Scheduler::FollowRecommendationsScheduler
 
         # Language-specific results should be above language-agnostic ones,
         # otherwise language-agnostic ones will always overshadow them
-        recommendations.map! { |(account_id, rank)| [account_id, rank + max_fallback_rank] }
+        recommendations.map! { |(rank, account_id)| [rank + max_fallback_rank, account_id] }
 
         added = 0
 
         fallback_recommendations.each do |recommendation|
-          next if recommendations.any? { |(account_id, _)| account_id == recommendation.account_id }
+          next if recommendations.any? { |(_, account_id)| account_id == recommendation.account_id }
 
-          recommendations << [recommendation.account_id, recommendation.rank]
+          recommendations << [recommendation.rank, recommendation.account_id]
           added += 1
 
           break if added >= missing
@@ -49,10 +49,7 @@ class Scheduler::FollowRecommendationsScheduler
 
       redis.multi do |multi|
         multi.del(key(locale))
-
-        recommendations.each do |(account_id, rank)|
-          multi.zadd(key(locale), rank, account_id)
-        end
+        multi.zadd(key(locale), recommendations)
       end
     end
   end
diff --git a/app/workers/unfollow_follow_worker.rb b/app/workers/unfollow_follow_worker.rb
index 7203b4888..a4d57839d 100644
--- a/app/workers/unfollow_follow_worker.rb
+++ b/app/workers/unfollow_follow_worker.rb
@@ -10,13 +10,7 @@ class UnfollowFollowWorker
     old_target_account = Account.find(old_target_account_id)
     new_target_account = Account.find(new_target_account_id)
 
-    follow    = follower_account.active_relationships.find_by(target_account: old_target_account)
-    reblogs   = follow&.show_reblogs?
-    notify    = follow&.notify?
-    languages = follow&.languages
-
-    FollowService.new.call(follower_account, new_target_account, reblogs: reblogs, notify: notify, languages: languages, bypass_locked: bypass_locked, bypass_limit: true)
-    UnfollowService.new.call(follower_account, old_target_account, skip_unmerge: true)
+    FollowMigrationService.new.call(follower_account, new_target_account, old_target_account, bypass_locked: bypass_locked)
   rescue ActiveRecord::RecordNotFound, Mastodon::NotPermittedError
     true
   end