diff --git a/.circleci/config.yml b/.circleci/config.yml
index 862fa126b..42d9b0b48 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -160,8 +160,45 @@ jobs:
           name: Create database
           command: ./bin/rails db:create
       - run:
-          name: Run migrations
+          command: ./bin/rails db:migrate VERSION=20171010025614
+          name: Run migrations up to v2.0.0
+      - run:
+          command: ./bin/rails tests:migrations:populate_v2
+          name: Populate database with test data
+      - run:
           command: ./bin/rails db:migrate
+          name: Run all remaining migrations
+
+  test-two-step-migrations:
+    <<: *defaults
+    docker:
+      - image: circleci/ruby:2.7-buster-node
+        environment: *ruby_environment
+      - image: circleci/postgres:12.2
+        environment:
+          POSTGRES_USER: root
+          POSTGRES_HOST_AUTH_METHOD: trust
+      - image: circleci/redis:5-alpine
+    steps:
+      - *attach_workspace
+      - *install_system_dependencies
+      - run:
+          command: ./bin/rails db:create
+          name: Create database
+      - run:
+          command: ./bin/rails db:migrate VERSION=20171010025614
+          name: Run migrations up to v2.0.0
+      - run:
+          command: ./bin/rails tests:migrations:populate_v2
+          name: Populate database with test data
+      - run:
+          command: ./bin/rails db:migrate
+          name: Run all pre-deployment migrations
+          evironment:
+            SKIP_POST_DEPLOYMENT_MIGRATIONS: true
+      - run:
+          command: ./bin/rails db:migrate
+          name: Run all post-deployment remaining migrations
 
   test-ruby2.7:
     <<: *defaults
@@ -233,6 +270,9 @@ workflows:
       - test-migrations:
           requires:
             - install-ruby2.7
+      - test-two-step-migrations:
+          requires:
+            - install-ruby2.7
       - test-ruby2.7:
           requires:
             - install-ruby2.7
diff --git a/.env.production.sample b/.env.production.sample
index 6f14c5804..ff6db83ca 100644
--- a/.env.production.sample
+++ b/.env.production.sample
@@ -4,6 +4,12 @@
 # not demonstrate all available configuration options. Please look at
 # https://docs.joinmastodon.org/admin/config/ for the full documentation.
 
+# Note that this file accepts slightly different syntax depending on whether
+# you are using `docker-compose` or not. In particular, if you use
+# `docker-compose`, the value of each declared variable will be taken verbatim,
+# including surrounding quotes.
+# See: https://github.com/mastodon/mastodon/issues/16895
+
 # Federation
 # ----------
 # This identifies your server and cannot be changed safely later
diff --git a/.github/workflows/build-image.yml b/.github/workflows/build-image.yml
new file mode 100644
index 000000000..58f2813d3
--- /dev/null
+++ b/.github/workflows/build-image.yml
@@ -0,0 +1,34 @@
+name: Build container image
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - "main"
+    tags:
+      - "*"
+jobs:
+  build-image:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: docker/setup-buildx-action@v1
+      - uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - uses: docker/metadata-action@v3
+        id: meta
+        with:
+          images: tootsuite/mastodon
+          flavor: |
+            latest=auto
+          tags: |
+            type=edge,branch=main
+            type=semver,pattern={{ raw }}
+      - uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          cache-from: type=registry,ref=tootsuite/mastodon:latest
+          cache-to: type=inline
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d749c255..658447ba8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,72 @@ Changelog
 
 All notable changes to this project will be documented in this file.
 
+## [3.3.1] - 2022-01-31
+### Added
+- Add more advanced migration tests ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/17393))
+- Add github workflow to build Docker images ([unasuke](https://github.com/mastodon/mastodon/pull/16973), [Gargron](https://github.com/mastodon/mastodon/pull/16980), [Gargron](https://github.com/mastodon/mastodon/pull/17000))
+
+### Fixed
+- Update some dependencies that were broken or unavailable
+- Fix some old migrations failing when skipping releases ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/17394))
+- Fix migrations script failing in certain edge cases ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/17398))
+- Fix media redownload worker retrying on unexpected response codes ([Gargron](https://github.com/tootsuite/mastodon/pull/16111))
+- Fix thread resolve worker retrying when status no longer exists ([Gargron](https://github.com/tootsuite/mastodon/pull/16109))
+- Fix n+1 queries when rendering statuses in REST API ([abcang](https://github.com/tootsuite/mastodon/pull/15641))
+- Fix remote reporters not receiving suspend/unsuspend activities ([Gargron](https://github.com/tootsuite/mastodon/pull/16050))
+- Fix understanding (not fully qualified) `as:Public` and `Public` ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15948))
+- Fix actor update not being distributed on profile picture deletion ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15461))
+- Fix processing of incoming Delete activities ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/16084))
+- Fix processing of incoming Block activities ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15546))
+- Fix processing of incoming Update activities of unknown accounts ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15514))
+- Fix URIs of repeat follow requests not being recorded ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15662))
+- Fix error on requests with no `Digest` header ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15782))
+- Fix activity object not requiring signature in secure mode ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15592))
+- Fix database serialization failure returning HTTP 500 ([Gargron](https://github.com/tootsuite/mastodon/pull/16101))
+- Fix media processing getting stuck on too much stdin/stderr ([Gargron](https://github.com/tootsuite/mastodon/pull/16136))
+- Fix `tootctl maintenance fix-duplicates` failures ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15923), [ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15515))
+- Fix blocking someone not clearing up list feeds ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/16205))
+- Fix edge case where follow limit interferes with accepting a follow ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/16098))
+- Fix reports of already suspended accounts being recorded ([Gargron](https://github.com/tootsuite/mastodon/pull/16047))
+- Fix sign-up restrictions based on IP addresses not being enforced ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15607))
+- Fix race conditions on account migration creation ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15597))
+- Fix not being able to change world filter expiration back to “Never” ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15858))
+- Fix error when muting users with `duration` in REST API ([Tak](https://github.com/tootsuite/mastodon/pull/15516))
+- Fix wrong URL to custom CSS when `CDN_HOST` is used ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15927))
+- Fix `tootctl accounts unfollow` ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15639))
+- Fix `tootctl emoji import` wasting time on MacOS shadow files ([cortices](https://github.com/tootsuite/mastodon/pull/15430))
+- Fix `tootctl emoji import` not treating shortcodes as case-insensitive ([angristan](https://github.com/tootsuite/mastodon/pull/15738))
+- Fix some issues with SAML account creation ([Gargron](https://github.com/tootsuite/mastodon/pull/15222), [kaiyou](https://github.com/tootsuite/mastodon/pull/15511
+- Fix instance actor not being automatically created if it wasn't seeded properly ([ClearlyClaire](https://github.com/tootsuite/mastodon/pull/15693))))
+- Fix app name, website and redirect URIs not having a maximum length ([Gargron](https://github.com/tootsuite/mastodon/pull/16042))
+- Fix some ActivityPub identifiers in server actor outbox ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16343))
+- Fix custom CSS path setting cookies and being uncacheable due to it ([tribela](https://github.com/mastodon/mastodon/pull/16314))
+- Fix some redis locks auto-releasing too fast ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16276), [ClearlyClaire](https://github.com/mastodon/mastodon/pull/16291))
+- Fix migration script not being able to run if it fails midway ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16312))
+- Fix PWA not being usable from alternate domains ([HolgerHuo](https://github.com/mastodon/mastodon/pull/16714))
+- Fix scheduling a status decreasing status count ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16791))
+- Fix followers synchronization mechanism not working when URI has empty path ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16744))
+- Fix serialization of counts in REST API when user hides their network ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16418))
+- Fix `tootctl self-destruct` not sending delete activities for recently-suspended accounts ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16688))
+- Fix `mastodon:setup` generated env-file syntax ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16896), [ClearlyClaire](https://github.com/mastodon/mastodon/pull/16976))
+- Fix link previews being incorrectly generated from earlier links ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16885))
+- Fix wrong `to`/`cc` values for remote groups in ActivityPub ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16700))
+- Fix mentions with non-ascii TLDs not being processed ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16689))
+- Fix authentication failures halfway through a sign-in attempt ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16607), [ClearlyClaire](https://github.com/mastodon/mastodon/pull/16792))
+- Fix suspended accounts statuses being merged back into timelines ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16628))
+- Fix crash when encountering invalid account fields ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16598))
+- Fix invalid blurhash handling for remote activities ([noellabo](https://github.com/mastodon/mastodon/pull/16583))
+- Fix newlines being added to accout notes when an account moves ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16415), [noellabo](https://github.com/mastodon/mastodon/pull/16576))
+- Fix logging out from one browser logging out all other sessions ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16943))
+- Fix confusing error when WebFinger request returns empty document ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16986))
+- Fix upload of remote media with OpenStack Swift sometimes failing ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16998))
+- Fix Docker build ([tribela](https://github.com/mastodon/mastodon/pull/17188))
+
+### Security
+- Fix user notes not having a length limit ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16942))
+- Fix revoking a specific session not working ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/16943))
+- Fix filtering DMs from non-followed users ([ClearlyClaire](https://github.com/mastodon/mastodon/pull/17042))
+
 ## [3.3.0] - 2020-12-27
 ### Added
 
diff --git a/Dockerfile b/Dockerfile
index 95d45bab4..d472c4b39 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -71,8 +71,8 @@ RUN npm install -g yarn && \
 COPY Gemfile* package.json yarn.lock /opt/mastodon/
 
 RUN cd /opt/mastodon && \
-  bundle config set deployment 'true' && \
-  bundle config set without 'development test' && \
+  bundle config set --local deployment 'true' && \
+  bundle config set --local without 'development test' && \
 	bundle install -j$(nproc) && \
 	yarn install --pure-lockfile
 
diff --git a/Gemfile b/Gemfile
index 3aee5d7cc..5d5fa144b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,8 +21,6 @@ gem 'aws-sdk-s3', '~> 1.85', require: false
 gem 'fog-core', '<= 2.1.0'
 gem 'fog-openstack', '~> 0.3', require: false
 gem 'paperclip', '~> 6.0'
-gem 'paperclip-av-transcoder', '~> 0.6'
-gem 'streamio-ffmpeg', '~> 3.0'
 gem 'blurhash', '~> 0.1'
 
 gem 'active_model_serializers', '~> 0.10'
diff --git a/Gemfile.lock b/Gemfile.lock
index c4c8d9904..9f4fe4e91 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -75,8 +75,6 @@ GEM
     ast (2.4.1)
     attr_encrypted (3.1.0)
       encryptor (~> 3.0.0)
-    av (0.9.0)
-      cocaine (~> 0.5.3)
     awrence (1.1.1)
     aws-eventstream (1.1.0)
     aws-partitions (1.397.0)
@@ -151,8 +149,6 @@ GEM
     cld3 (3.3.0)
       ffi (>= 1.1.0, < 1.12.0)
     climate_control (0.2.0)
-    cocaine (0.5.8)
-      climate_control (>= 0.0.3, < 1.0)
     coderay (1.1.3)
     color_diff (0.1)
     concurrent-ruby (1.1.7)
@@ -346,9 +342,11 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2020.0512)
-    mimemagic (0.3.5)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.7.1)
     minitest (5.14.2)
     msgpack (1.3.3)
     multi_json (1.15.0)
@@ -358,9 +356,10 @@ GEM
       net-ssh (>= 2.6.5, < 7.0.0)
     net-ssh (6.1.0)
     nio4r (2.5.4)
-    nokogiri (1.10.10)
-      mini_portile2 (~> 2.4.0)
-    nokogumbo (2.0.2)
+    nokogiri (1.13.1)
+      mini_portile2 (~> 2.7.0)
+      racc (~> 1.4)
+    nokogumbo (2.0.5)
       nokogiri (~> 1.8, >= 1.8.4)
     nsa (0.2.7)
       activesupport (>= 4.2, < 6)
@@ -391,9 +390,6 @@ GEM
       mime-types
       mimemagic (~> 0.3.0)
       terrapin (~> 0.6.0)
-    paperclip-av-transcoder (0.6.4)
-      av (~> 0.9.0)
-      paperclip (>= 2.5.2)
     parallel (1.20.1)
     parallel_tests (3.4.0)
       parallel
@@ -432,6 +428,7 @@ GEM
     pundit (2.1.0)
       activesupport (>= 3.0.0)
     raabro (1.3.3)
+    racc (1.6.0)
     rack (2.2.3)
     rack-attack (6.3.1)
       rack (>= 1.0, < 3)
@@ -605,8 +602,6 @@ GEM
     stackprof (0.2.16)
     statsd-ruby (1.4.0)
     stoplight (2.2.1)
-    streamio-ffmpeg (3.0.2)
-      multi_json (~> 1.8)
     strong_migrations (0.7.2)
       activerecord (>= 5)
     temple (0.8.2)
@@ -751,7 +746,6 @@ DEPENDENCIES
   omniauth-saml (~> 1.10)
   ox (~> 2.13)
   paperclip (~> 6.0)
-  paperclip-av-transcoder (~> 0.6)
   parallel (~> 1.20)
   parallel_tests (~> 3.4)
   parslet
@@ -797,7 +791,6 @@ DEPENDENCIES
   sprockets-rails (~> 3.2)
   stackprof
   stoplight (~> 2.2.1)
-  streamio-ffmpeg (~> 3.0)
   strong_migrations (~> 0.7)
   thor (~> 1.0)
   tty-prompt (~> 0.22)
diff --git a/app/controllers/activitypub/followers_synchronizations_controller.rb b/app/controllers/activitypub/followers_synchronizations_controller.rb
index 525031105..940b77cf0 100644
--- a/app/controllers/activitypub/followers_synchronizations_controller.rb
+++ b/app/controllers/activitypub/followers_synchronizations_controller.rb
@@ -19,11 +19,11 @@ class ActivityPub::FollowersSynchronizationsController < ActivityPub::BaseContro
   private
 
   def uri_prefix
-    signed_request_account.uri[/http(s?):\/\/[^\/]+\//]
+    signed_request_account.uri[Account::URL_PREFIX_RE]
   end
 
   def set_items
-    @items = @account.followers.where(Account.arel_table[:uri].matches(uri_prefix + '%', false, true)).pluck(:uri)
+    @items = @account.followers.where(Account.arel_table[:uri].matches("#{Account.sanitize_sql_like(uri_prefix)}/%", false, true)).or(@account.followers.where(uri: uri_prefix)).pluck(:uri)
   end
 
   def collection_presenter
diff --git a/app/controllers/activitypub/inboxes_controller.rb b/app/controllers/activitypub/inboxes_controller.rb
index d3044f180..92dcb5ac7 100644
--- a/app/controllers/activitypub/inboxes_controller.rb
+++ b/app/controllers/activitypub/inboxes_controller.rb
@@ -5,7 +5,7 @@ class ActivityPub::InboxesController < ActivityPub::BaseController
   include JsonLdHelper
   include AccountOwnedConcern
 
-  before_action :skip_unknown_actor_delete
+  before_action :skip_unknown_actor_activity
   before_action :require_signature!
   skip_before_action :authenticate_user!
 
@@ -18,13 +18,13 @@ class ActivityPub::InboxesController < ActivityPub::BaseController
 
   private
 
-  def skip_unknown_actor_delete
-    head 202 if unknown_deleted_account?
+  def skip_unknown_actor_activity
+    head 202 if unknown_affected_account?
   end
 
-  def unknown_deleted_account?
+  def unknown_affected_account?
     json = Oj.load(body, mode: :strict)
-    json.is_a?(Hash) && json['type'] == 'Delete' && json['actor'].present? && json['actor'] == value_or_id(json['object']) && !Account.where(uri: json['actor']).exists?
+    json.is_a?(Hash) && %w(Delete Update).include?(json['type']) && json['actor'].present? && json['actor'] == value_or_id(json['object']) && !Account.where(uri: json['actor']).exists?
   rescue Oj::ParseError
     false
   end
diff --git a/app/controllers/activitypub/outboxes_controller.rb b/app/controllers/activitypub/outboxes_controller.rb
index 5fd735ad6..338b703a6 100644
--- a/app/controllers/activitypub/outboxes_controller.rb
+++ b/app/controllers/activitypub/outboxes_controller.rb
@@ -29,7 +29,7 @@ class ActivityPub::OutboxesController < ActivityPub::BaseController
       )
     else
       ActivityPub::CollectionPresenter.new(
-        id: account_outbox_url(@account),
+        id: outbox_url,
         type: :ordered,
         size: @account.statuses_count,
         first: outbox_url(page: true),
@@ -47,11 +47,11 @@ class ActivityPub::OutboxesController < ActivityPub::BaseController
   end
 
   def next_page
-    account_outbox_url(@account, page: true, max_id: @statuses.last.id) if @statuses.size == LIMIT
+    outbox_url(page: true, max_id: @statuses.last.id) if @statuses.size == LIMIT
   end
 
   def prev_page
-    account_outbox_url(@account, page: true, min_id: @statuses.first.id) unless @statuses.empty?
+    outbox_url(page: true, min_id: @statuses.first.id) unless @statuses.empty?
   end
 
   def set_statuses
diff --git a/app/controllers/api/v1/accounts_controller.rb b/app/controllers/api/v1/accounts_controller.rb
index 3e66ff212..953874e1a 100644
--- a/app/controllers/api/v1/accounts_controller.rb
+++ b/app/controllers/api/v1/accounts_controller.rb
@@ -42,7 +42,7 @@ class Api::V1::AccountsController < Api::BaseController
   end
 
   def mute
-    MuteService.new.call(current_user.account, @account, notifications: truthy_param?(:notifications), duration: (params[:duration] || 0))
+    MuteService.new.call(current_user.account, @account, notifications: truthy_param?(:notifications), duration: (params[:duration]&.to_i || 0))
     render json: @account, serializer: REST::RelationshipSerializer, relationships: relationships
   end
 
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 44616d6e5..d47bdf3ac 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -20,17 +20,16 @@ class ApplicationController < ActionController::Base
   helper_method :use_seamless_external_login?
   helper_method :whitelist_mode?
 
-  rescue_from ActionController::RoutingError, with: :not_found
-  rescue_from ActionController::InvalidAuthenticityToken, with: :unprocessable_entity
-  rescue_from ActionController::UnknownFormat, with: :not_acceptable
-  rescue_from ActionController::ParameterMissing, with: :bad_request
-  rescue_from Paperclip::AdapterRegistry::NoHandlerError, with: :bad_request
-  rescue_from ActiveRecord::RecordNotFound, with: :not_found
+  rescue_from ActionController::ParameterMissing, Paperclip::AdapterRegistry::NoHandlerError, with: :bad_request
   rescue_from Mastodon::NotPermittedError, with: :forbidden
-  rescue_from HTTP::Error, OpenSSL::SSL::SSLError, with: :internal_server_error
-  rescue_from Mastodon::RaceConditionError, Seahorse::Client::NetworkingError, Stoplight::Error::RedLight, with: :service_unavailable
+  rescue_from ActionController::RoutingError, ActiveRecord::RecordNotFound, with: :not_found
+  rescue_from ActionController::UnknownFormat, with: :not_acceptable
+  rescue_from ActionController::InvalidAuthenticityToken, with: :unprocessable_entity
   rescue_from Mastodon::RateLimitExceededError, with: :too_many_requests
 
+  rescue_from HTTP::Error, OpenSSL::SSL::SSLError, with: :internal_server_error
+  rescue_from Mastodon::RaceConditionError, Seahorse::Client::NetworkingError, Stoplight::Error::RedLight, ActiveRecord::SerializationFailure, with: :service_unavailable
+
   before_action :store_current_location, except: :raise_not_found, unless: :devise_controller?
   before_action :require_functional!, if: :user_signed_in?
 
diff --git a/app/controllers/auth/passwords_controller.rb b/app/controllers/auth/passwords_controller.rb
index 5db2668f7..2996c0431 100644
--- a/app/controllers/auth/passwords_controller.rb
+++ b/app/controllers/auth/passwords_controller.rb
@@ -10,7 +10,6 @@ class Auth::PasswordsController < Devise::PasswordsController
     super do |resource|
       if resource.errors.empty?
         resource.session_activations.destroy_all
-        resource.forget_me!
       end
     end
   end
diff --git a/app/controllers/auth/registrations_controller.rb b/app/controllers/auth/registrations_controller.rb
index 0ba0fd9f2..d4892cdc2 100644
--- a/app/controllers/auth/registrations_controller.rb
+++ b/app/controllers/auth/registrations_controller.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 class Auth::RegistrationsController < Devise::RegistrationsController
-  include Devise::Controllers::Rememberable
   include RegistrationSpamConcern
 
   layout :determine_layout
@@ -30,8 +29,6 @@ class Auth::RegistrationsController < Devise::RegistrationsController
     super do |resource|
       if resource.saved_change_to_encrypted_password?
         resource.clear_other_sessions(current_session.session_id)
-        resource.forget_me!
-        remember_me(resource)
       end
     end
   end
diff --git a/app/controllers/auth/sessions_controller.rb b/app/controllers/auth/sessions_controller.rb
index 13d158c67..630b0dee5 100644
--- a/app/controllers/auth/sessions_controller.rb
+++ b/app/controllers/auth/sessions_controller.rb
@@ -1,8 +1,6 @@
 # frozen_string_literal: true
 
 class Auth::SessionsController < Devise::SessionsController
-  include Devise::Controllers::Rememberable
-
   layout 'auth'
 
   skip_before_action :require_no_authentication, only: [:create]
@@ -26,7 +24,6 @@ class Auth::SessionsController < Devise::SessionsController
   def create
     super do |resource|
       resource.update_sign_in!(request, new_sign_in: true)
-      remember_me(resource)
       flash.delete(:notice)
     end
   end
@@ -40,7 +37,7 @@ class Auth::SessionsController < Devise::SessionsController
   end
 
   def webauthn_options
-    user = find_user
+    user = User.find_by(id: session[:attempt_user_id])
 
     if user.webauthn_enabled?
       options_for_get = WebAuthn::Credential.options_for_get(
@@ -58,16 +55,20 @@ class Auth::SessionsController < Devise::SessionsController
   protected
 
   def find_user
-    if session[:attempt_user_id]
+    if user_params[:email].present?
+      find_user_from_params
+    elsif session[:attempt_user_id]
       User.find_by(id: session[:attempt_user_id])
-    else
-      user   = User.authenticate_with_ldap(user_params) if Devise.ldap_authentication
-      user ||= User.authenticate_with_pam(user_params) if Devise.pam_authentication
-      user ||= User.find_for_authentication(email: user_params[:email])
-      user
     end
   end
 
+  def find_user_from_params
+    user   = User.authenticate_with_ldap(user_params) if Devise.ldap_authentication
+    user ||= User.authenticate_with_pam(user_params) if Devise.pam_authentication
+    user ||= User.find_for_authentication(email: user_params[:email])
+    user
+  end
+
   def user_params
     params.require(:user).permit(:email, :password, :otp_attempt, :sign_in_token_attempt, credential: {})
   end
diff --git a/app/controllers/concerns/sign_in_token_authentication_concern.rb b/app/controllers/concerns/sign_in_token_authentication_concern.rb
index 3c95a4afd..2b5e79115 100644
--- a/app/controllers/concerns/sign_in_token_authentication_concern.rb
+++ b/app/controllers/concerns/sign_in_token_authentication_concern.rb
@@ -16,21 +16,24 @@ module SignInTokenAuthenticationConcern
   end
 
   def authenticate_with_sign_in_token
-    user = self.resource = find_user
+    if user_params[:email].present?
+      user = self.resource = find_user_from_params
+      prompt_for_sign_in_token(user) if user&.external_or_valid_password?(user_params[:password])
+    elsif session[:attempt_user_id]
+      user = self.resource = User.find_by(id: session[:attempt_user_id])
+      return if user.nil?
 
-    if user.present? && session[:attempt_user_id].present? && session[:attempt_user_updated_at] != user.updated_at.to_s
-      restart_session
-    elsif user_params.key?(:sign_in_token_attempt) && session[:attempt_user_id]
-      authenticate_with_sign_in_token_attempt(user)
-    elsif user.present? && user.external_or_valid_password?(user_params[:password])
-      prompt_for_sign_in_token(user)
+      if session[:attempt_user_updated_at] != user.updated_at.to_s
+        restart_session
+      elsif user_params.key?(:sign_in_token_attempt)
+        authenticate_with_sign_in_token_attempt(user)
+      end
     end
   end
 
   def authenticate_with_sign_in_token_attempt(user)
     if valid_sign_in_token_attempt?(user)
       clear_attempt_from_session
-      remember_me(user)
       sign_in(user)
     else
       flash.now[:alert] = I18n.t('users.invalid_sign_in_token')
diff --git a/app/controllers/concerns/signature_verification.rb b/app/controllers/concerns/signature_verification.rb
index fc3978fbb..4dd0cac55 100644
--- a/app/controllers/concerns/signature_verification.rb
+++ b/app/controllers/concerns/signature_verification.rb
@@ -133,6 +133,7 @@ module SignatureVerification
 
   def verify_body_digest!
     return unless signed_headers.include?('digest')
+    raise SignatureVerificationError, 'Digest header missing' unless request.headers.key?('Digest')
 
     digests = request.headers['Digest'].split(',').map { |digest| digest.split('=', 2) }.map { |key, value| [key.downcase, value] }
     sha256  = digests.assoc('sha-256')
diff --git a/app/controllers/concerns/two_factor_authentication_concern.rb b/app/controllers/concerns/two_factor_authentication_concern.rb
index 4d4ccf49c..d65f072ff 100644
--- a/app/controllers/concerns/two_factor_authentication_concern.rb
+++ b/app/controllers/concerns/two_factor_authentication_concern.rb
@@ -35,16 +35,20 @@ module TwoFactorAuthenticationConcern
   end
 
   def authenticate_with_two_factor
-    user = self.resource = find_user
+    if user_params[:email].present?
+      user = self.resource = find_user_from_params
+      prompt_for_two_factor(user) if user&.external_or_valid_password?(user_params[:password])
+    elsif session[:attempt_user_id]
+      user = self.resource = User.find_by(id: session[:attempt_user_id])
+      return if user.nil?
 
-    if user.present? && session[:attempt_user_id].present? && session[:attempt_user_updated_at] != user.updated_at.to_s
-      restart_session
-    elsif user.webauthn_enabled? && user_params.key?(:credential) && session[:attempt_user_id]
-      authenticate_with_two_factor_via_webauthn(user)
-    elsif user_params.key?(:otp_attempt) && session[:attempt_user_id]
-      authenticate_with_two_factor_via_otp(user)
-    elsif user.present? && user.external_or_valid_password?(user_params[:password])
-      prompt_for_two_factor(user)
+      if session[:attempt_user_updated_at] != user.updated_at.to_s
+        restart_session
+      elsif user.webauthn_enabled? && user_params.key?(:credential)
+        authenticate_with_two_factor_via_webauthn(user)
+      elsif user_params.key?(:otp_attempt)
+        authenticate_with_two_factor_via_otp(user)
+      end
     end
   end
 
@@ -53,7 +57,6 @@ module TwoFactorAuthenticationConcern
 
     if valid_webauthn_credential?(user, webauthn_credential)
       clear_attempt_from_session
-      remember_me(user)
       sign_in(user)
       render json: { redirect_path: root_path }, status: :ok
     else
@@ -64,7 +67,6 @@ module TwoFactorAuthenticationConcern
   def authenticate_with_two_factor_via_otp(user)
     if valid_otp_attempt?(user)
       clear_attempt_from_session
-      remember_me(user)
       sign_in(user)
     else
       flash.now[:alert] = I18n.t('users.invalid_otp_token')
diff --git a/app/controllers/custom_css_controller.rb b/app/controllers/custom_css_controller.rb
index 0a667a6a6..e1dc5eaf6 100644
--- a/app/controllers/custom_css_controller.rb
+++ b/app/controllers/custom_css_controller.rb
@@ -3,11 +3,16 @@
 class CustomCssController < ApplicationController
   skip_before_action :store_current_location
   skip_before_action :require_functional!
+  skip_before_action :update_user_sign_in
+  skip_before_action :set_session_activity
+
+  skip_around_action :set_locale
 
   before_action :set_cache_headers
 
   def show
     expires_in 3.minutes, public: true
+    request.session_options[:skip] = true
     render plain: Setting.custom_css || '', content_type: 'text/css'
   end
 end
diff --git a/app/controllers/follower_accounts_controller.rb b/app/controllers/follower_accounts_controller.rb
index ff4df2adf..b3589a39f 100644
--- a/app/controllers/follower_accounts_controller.rb
+++ b/app/controllers/follower_accounts_controller.rb
@@ -85,7 +85,7 @@ class FollowerAccountsController < ApplicationController
     if page_requested? || !@account.user_hides_network?
       # Return all fields
     else
-      %i(id type totalItems)
+      %i(id type total_items)
     end
   end
 end
diff --git a/app/controllers/following_accounts_controller.rb b/app/controllers/following_accounts_controller.rb
index 6bb95c454..8a72dc475 100644
--- a/app/controllers/following_accounts_controller.rb
+++ b/app/controllers/following_accounts_controller.rb
@@ -85,7 +85,7 @@ class FollowingAccountsController < ApplicationController
     if page_requested? || !@account.user_hides_network?
       # Return all fields
     else
-      %i(id type totalItems)
+      %i(id type total_items)
     end
   end
 end
diff --git a/app/controllers/instance_actors_controller.rb b/app/controllers/instance_actors_controller.rb
index 4b074ca19..b3b5476e2 100644
--- a/app/controllers/instance_actors_controller.rb
+++ b/app/controllers/instance_actors_controller.rb
@@ -13,7 +13,7 @@ class InstanceActorsController < ApplicationController
   private
 
   def set_account
-    @account = Account.find(-99)
+    @account = Account.representative
   end
 
   def restrict_fields_to
diff --git a/app/controllers/media_proxy_controller.rb b/app/controllers/media_proxy_controller.rb
index 0b1d09de9..5807cc6fc 100644
--- a/app/controllers/media_proxy_controller.rb
+++ b/app/controllers/media_proxy_controller.rb
@@ -45,7 +45,7 @@ class MediaProxyController < ApplicationController
   end
 
   def lock_options
-    { redis: Redis.current, key: "media_download:#{params[:id]}" }
+    { redis: Redis.current, key: "media_download:#{params[:id]}", autorelease: 15.minutes.seconds }
   end
 
   def reject_media?
diff --git a/app/controllers/settings/pictures_controller.rb b/app/controllers/settings/pictures_controller.rb
index 28df65f8f..58a432530 100644
--- a/app/controllers/settings/pictures_controller.rb
+++ b/app/controllers/settings/pictures_controller.rb
@@ -7,8 +7,12 @@ module Settings
 
     def destroy
       if valid_picture?
-        msg = I18n.t('generic.changes_saved_msg') if UpdateAccountService.new.call(@account, { @picture => nil, "#{@picture}_remote_url" => '' })
-        redirect_to settings_profile_path, notice: msg, status: 303
+        if UpdateAccountService.new.call(@account, { @picture => nil, "#{@picture}_remote_url" => '' })
+          ActivityPub::UpdateDistributionWorker.perform_async(@account.id)
+          redirect_to settings_profile_path, notice: I18n.t('generic.changes_saved_msg'), status: 303
+        else
+          redirect_to settings_profile_path
+        end
       else
         bad_request
       end
diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index 17ddd31fb..87612a296 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -8,7 +8,7 @@ class StatusesController < ApplicationController
 
   layout 'public'
 
-  before_action :require_signature!, only: :show, if: -> { request.format == :json && authorized_fetch_mode? }
+  before_action :require_signature!, only: [:show, :activity], if: -> { request.format == :json && authorized_fetch_mode? }
   before_action :set_status
   before_action :set_instance_presenter
   before_action :set_link_headers
diff --git a/app/lib/account_reach_finder.rb b/app/lib/account_reach_finder.rb
new file mode 100644
index 000000000..706ce8c1f
--- /dev/null
+++ b/app/lib/account_reach_finder.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class AccountReachFinder
+  def initialize(account)
+    @account = account
+  end
+
+  def inboxes
+    (followers_inboxes + reporters_inboxes + relay_inboxes).uniq
+  end
+
+  private
+
+  def followers_inboxes
+    @account.followers.inboxes
+  end
+
+  def reporters_inboxes
+    Account.where(id: @account.targeted_reports.select(:account_id)).inboxes
+  end
+
+  def relay_inboxes
+    Relay.enabled.pluck(:inbox_url)
+  end
+end
diff --git a/app/lib/activitypub/activity.rb b/app/lib/activitypub/activity.rb
index 2b5d3ffc2..d2ec122a4 100644
--- a/app/lib/activitypub/activity.rb
+++ b/app/lib/activitypub/activity.rb
@@ -144,7 +144,7 @@ class ActivityPub::Activity
   end
 
   def delete_later!(uri)
-    redis.setex("delete_upon_arrival:#{@account.id}:#{uri}", 6.hours.seconds, uri)
+    redis.setex("delete_upon_arrival:#{@account.id}:#{uri}", 6.hours.seconds, true)
   end
 
   def status_from_object
@@ -210,12 +210,22 @@ class ActivityPub::Activity
     end
   end
 
-  def lock_or_return(key, expire_after = 7.days.seconds)
+  def lock_or_return(key, expire_after = 2.hours.seconds)
     yield if redis.set(key, true, nx: true, ex: expire_after)
   ensure
     redis.del(key)
   end
 
+  def lock_or_fail(key, expire_after = 15.minutes.seconds)
+    RedisLock.acquire({ redis: Redis.current, key: key, autorelease: expire_after }) do |lock|
+      if lock.acquired?
+        yield
+      else
+        raise Mastodon::RaceConditionError
+      end
+    end
+  end
+
   def fetch?
     !@options[:delivery]
   end
diff --git a/app/lib/activitypub/activity/announce.rb b/app/lib/activitypub/activity/announce.rb
index 349e8f77e..a1081522e 100644
--- a/app/lib/activitypub/activity/announce.rb
+++ b/app/lib/activitypub/activity/announce.rb
@@ -4,29 +4,25 @@ class ActivityPub::Activity::Announce < ActivityPub::Activity
   def perform
     return reject_payload! if delete_arrived_first?(@json['id']) || !related_to_local_activity?
 
-    RedisLock.acquire(lock_options) do |lock|
-      if lock.acquired?
-        original_status = status_from_object
+    lock_or_fail("announce:#{@object['id']}") do
+      original_status = status_from_object
 
-        return reject_payload! if original_status.nil? || !announceable?(original_status)
+      return reject_payload! if original_status.nil? || !announceable?(original_status)
 
-        @status = Status.find_by(account: @account, reblog: original_status)
+      @status = Status.find_by(account: @account, reblog: original_status)
 
-        return @status unless @status.nil?
+      return @status unless @status.nil?
 
-        @status = Status.create!(
-          account: @account,
-          reblog: original_status,
-          uri: @json['id'],
-          created_at: @json['published'],
-          override_timestamps: @options[:override_timestamps],
-          visibility: visibility_from_audience
-        )
+      @status = Status.create!(
+        account: @account,
+        reblog: original_status,
+        uri: @json['id'],
+        created_at: @json['published'],
+        override_timestamps: @options[:override_timestamps],
+        visibility: visibility_from_audience
+      )
 
-        distribute(@status)
-      else
-        raise Mastodon::RaceConditionError
-      end
+      distribute(@status)
     end
 
     @status
@@ -43,9 +39,9 @@ class ActivityPub::Activity::Announce < ActivityPub::Activity
   end
 
   def visibility_from_audience
-    if audience_to.include?(ActivityPub::TagManager::COLLECTIONS[:public])
+    if audience_to.any? { |to| ActivityPub::TagManager.instance.public_collection?(to) }
       :public
-    elsif audience_cc.include?(ActivityPub::TagManager::COLLECTIONS[:public])
+    elsif audience_cc.any? { |cc| ActivityPub::TagManager.instance.public_collection?(cc) }
       :unlisted
     elsif audience_to.include?(@account.followers_url)
       :private
@@ -69,8 +65,4 @@ class ActivityPub::Activity::Announce < ActivityPub::Activity
   def reblog_of_local_status?
     status_from_uri(object_uri)&.account&.local?
   end
-
-  def lock_options
-    { redis: Redis.current, key: "announce:#{@object['id']}" }
-  end
 end
diff --git a/app/lib/activitypub/activity/block.rb b/app/lib/activitypub/activity/block.rb
index 90477bf33..92a0f813f 100644
--- a/app/lib/activitypub/activity/block.rb
+++ b/app/lib/activitypub/activity/block.rb
@@ -11,8 +11,13 @@ class ActivityPub::Activity::Block < ActivityPub::Activity
       return
     end
 
+    UnfollowService.new.call(@account, target_account) if @account.following?(target_account)
     UnfollowService.new.call(target_account, @account) if target_account.following?(@account)
+    RejectFollowService.new.call(target_account, @account) if target_account.requested?(@account)
 
-    @account.block!(target_account, uri: @json['id']) unless delete_arrived_first?(@json['id'])
+    unless delete_arrived_first?(@json['id'])
+      BlockWorker.perform_async(@account.id, target_account.id)
+      @account.block!(target_account, uri: @json['id'])
+    end
   end
 end
diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 612744676..9607f555e 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -45,19 +45,15 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def create_status
     return reject_payload! if unsupported_object_type? || invalid_origin?(object_uri) || tombstone_exists? || !related_to_local_activity?
 
-    RedisLock.acquire(lock_options) do |lock|
-      if lock.acquired?
-        return if delete_arrived_first?(object_uri) || poll_vote? # rubocop:disable Lint/NonLocalExitFromIterator
+    lock_or_fail("create:#{object_uri}") do
+      return if delete_arrived_first?(object_uri) || poll_vote? # rubocop:disable Lint/NonLocalExitFromIterator
 
-        @status = find_existing_status
+      @status = find_existing_status
 
-        if @status.nil?
-          process_status
-        elsif @options[:delivered_to_account_id].present?
-          postprocess_audience_and_deliver
-        end
-      else
-        raise Mastodon::RaceConditionError
+      if @status.nil?
+        process_status
+      elsif @options[:delivered_to_account_id].present?
+        postprocess_audience_and_deliver
       end
     end
 
@@ -123,7 +119,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def process_audience
     (audience_to + audience_cc).uniq.each do |audience|
-      next if audience == ActivityPub::TagManager::COLLECTIONS[:public]
+      next if ActivityPub::TagManager.instance.public_collection?(audience)
 
       # Unlike with tags, there is no point in resolving accounts we don't already
       # know here, because silent mentions would only be used for local access
@@ -314,13 +310,9 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     poll = replied_to_status.preloadable_poll
     already_voted = true
 
-    RedisLock.acquire(poll_lock_options) do |lock|
-      if lock.acquired?
-        already_voted = poll.votes.where(account: @account).exists?
-        poll.votes.create!(account: @account, choice: poll.options.index(@object['name']), uri: object_uri)
-      else
-        raise Mastodon::RaceConditionError
-      end
+    lock_or_fail("vote:#{replied_to_status.poll_id}:#{@account.id}") do
+      already_voted = poll.votes.where(account: @account).exists?
+      poll.votes.create!(account: @account, choice: poll.options.index(@object['name']), uri: object_uri)
     end
 
     increment_voters_count! unless already_voted
@@ -356,9 +348,9 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   end
 
   def visibility_from_audience
-    if audience_to.include?(ActivityPub::TagManager::COLLECTIONS[:public])
+    if audience_to.any? { |to| ActivityPub::TagManager.instance.public_collection?(to) }
       :public
-    elsif audience_cc.include?(ActivityPub::TagManager::COLLECTIONS[:public])
+    elsif audience_cc.any? { |cc| ActivityPub::TagManager.instance.public_collection?(cc) }
       :unlisted
     elsif audience_to.include?(@account.followers_url)
       :private
@@ -455,10 +447,14 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   end
 
   def supported_blurhash?(blurhash)
-    components = blurhash.blank? ? nil : Blurhash.components(blurhash)
+    components = blurhash.blank? || !blurhash_valid_chars?(blurhash) ? nil : Blurhash.components(blurhash)
     components.present? && components.none? { |comp| comp > 5 }
   end
 
+  def blurhash_valid_chars?(blurhash)
+    /^[\w#$%*+-.:;=?@\[\]^{|}~]+$/.match?(blurhash)
+  end
+
   def skip_download?
     return @skip_download if defined?(@skip_download)
 
@@ -513,12 +509,4 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     poll.reload
     retry
   end
-
-  def lock_options
-    { redis: Redis.current, key: "create:#{object_uri}" }
-  end
-
-  def poll_lock_options
-    { redis: Redis.current, key: "vote:#{replied_to_status.poll_id}:#{@account.id}" }
-  end
 end
diff --git a/app/lib/activitypub/activity/delete.rb b/app/lib/activitypub/activity/delete.rb
index 2e5293b83..801647cf7 100644
--- a/app/lib/activitypub/activity/delete.rb
+++ b/app/lib/activitypub/activity/delete.rb
@@ -20,33 +20,35 @@ class ActivityPub::Activity::Delete < ActivityPub::Activity
   def delete_note
     return if object_uri.nil?
 
-    unless invalid_origin?(object_uri)
-      RedisLock.acquire(lock_options) { |_lock| delete_later!(object_uri) }
-      Tombstone.find_or_create_by(uri: object_uri, account: @account)
+    lock_or_return("delete_status_in_progress:#{object_uri}", 5.minutes.seconds) do
+      unless invalid_origin?(object_uri)
+        # This lock ensures a concurrent `ActivityPub::Activity::Create` either
+        # does not create a status at all, or has finished saving it to the
+        # database before we try to load it.
+        # Without the lock, `delete_later!` could be called after `delete_arrived_first?`
+        # and `Status.find` before `Status.create!`
+        lock_or_fail("create:#{object_uri}") { delete_later!(object_uri) }
+
+        Tombstone.find_or_create_by(uri: object_uri, account: @account)
+      end
+
+      @status   = Status.find_by(uri: object_uri, account: @account)
+      @status ||= Status.find_by(uri: @object['atomUri'], account: @account) if @object.is_a?(Hash) && @object['atomUri'].present?
+
+      return if @status.nil?
+
+      forward! if @json['signature'].present? && @status.distributable?
+      delete_now!
     end
-
-    @status   = Status.find_by(uri: object_uri, account: @account)
-    @status ||= Status.find_by(uri: @object['atomUri'], account: @account) if @object.is_a?(Hash) && @object['atomUri'].present?
-
-    return if @status.nil?
-
-    if @status.distributable?
-      forward_for_reply
-      forward_for_reblogs
-    end
-
-    delete_now!
   end
 
-  def forward_for_reblogs
-    return if @json['signature'].blank?
+  def rebloggers_ids
+    return @rebloggers_ids if defined?(@rebloggers_ids)
+    @rebloggers_ids = @status.reblogs.includes(:account).references(:account).merge(Account.local).pluck(:account_id)
+  end
 
-    rebloggers_ids = @status.reblogs.includes(:account).references(:account).merge(Account.local).pluck(:account_id)
-    inboxes        = Account.where(id: ::Follow.where(target_account_id: rebloggers_ids).select(:account_id)).inboxes - [@account.preferred_inbox_url]
-
-    ActivityPub::LowPriorityDeliveryWorker.push_bulk(inboxes) do |inbox_url|
-      [payload, rebloggers_ids.first, inbox_url]
-    end
+  def inboxes_for_reblogs
+    Account.where(id: ::Follow.where(target_account_id: rebloggers_ids).select(:account_id)).inboxes
   end
 
   def replied_to_status
@@ -58,13 +60,19 @@ class ActivityPub::Activity::Delete < ActivityPub::Activity
     !replied_to_status.nil? && replied_to_status.account.local?
   end
 
-  def forward_for_reply
-    return unless @json['signature'].present? && reply_to_local?
+  def inboxes_for_reply
+    replied_to_status.account.followers.inboxes
+  end
 
-    inboxes = replied_to_status.account.followers.inboxes - [@account.preferred_inbox_url]
+  def forward!
+    inboxes = inboxes_for_reblogs
+    inboxes += inboxes_for_reply if reply_to_local?
+    inboxes -= [@account.preferred_inbox_url]
 
-    ActivityPub::LowPriorityDeliveryWorker.push_bulk(inboxes) do |inbox_url|
-      [payload, replied_to_status.account_id, inbox_url]
+    sender_id = reply_to_local? ? replied_to_status.account_id : rebloggers_ids.first
+
+    ActivityPub::LowPriorityDeliveryWorker.push_bulk(inboxes.uniq) do |inbox_url|
+      [payload, sender_id, inbox_url]
     end
   end
 
@@ -75,8 +83,4 @@ class ActivityPub::Activity::Delete < ActivityPub::Activity
   def payload
     @payload ||= Oj.dump(@json)
   end
-
-  def lock_options
-    { redis: Redis.current, key: "create:#{object_uri}" }
-  end
 end
diff --git a/app/lib/activitypub/activity/flag.rb b/app/lib/activitypub/activity/flag.rb
index 1659bc61f..7a5821064 100644
--- a/app/lib/activitypub/activity/flag.rb
+++ b/app/lib/activitypub/activity/flag.rb
@@ -10,6 +10,8 @@ class ActivityPub::Activity::Flag < ActivityPub::Activity
     target_accounts.each do |target_account|
       target_statuses = target_statuses_by_account[target_account.id]
 
+      next if target_account.suspended?
+
       ReportService.new.call(
         @account,
         target_account,
diff --git a/app/lib/activitypub/activity/follow.rb b/app/lib/activitypub/activity/follow.rb
index 0beec68ab..4efb84b8c 100644
--- a/app/lib/activitypub/activity/follow.rb
+++ b/app/lib/activitypub/activity/follow.rb
@@ -6,7 +6,14 @@ class ActivityPub::Activity::Follow < ActivityPub::Activity
   def perform
     target_account = account_from_uri(object_uri)
 
-    return if target_account.nil? || !target_account.local? || delete_arrived_first?(@json['id']) || @account.requested?(target_account)
+    return if target_account.nil? || !target_account.local? || delete_arrived_first?(@json['id'])
+
+    # Update id of already-existing follow requests
+    existing_follow_request = ::FollowRequest.find_by(account: @account, target_account: target_account)
+    unless existing_follow_request.nil?
+      existing_follow_request.update!(uri: @json['id'])
+      return
+    end
 
     if target_account.blocking?(@account) || target_account.domain_blocking?(@account.domain) || target_account.moved? || target_account.instance_actor?
       reject_follow_request!(target_account)
@@ -14,7 +21,9 @@ class ActivityPub::Activity::Follow < ActivityPub::Activity
     end
 
     # Fast-forward repeat follow requests
-    if @account.following?(target_account)
+    existing_follow = ::Follow.find_by(account: @account, target_account: target_account)
+    unless existing_follow.nil?
+      existing_follow.update!(uri: @json['id'])
       AuthorizeFollowService.new.call(@account, target_account, skip_follow_request: true, follow_request_uri: @json['id'])
       return
     end
diff --git a/app/lib/activitypub/activity/move.rb b/app/lib/activitypub/activity/move.rb
index 7e073f64d..8576ceccd 100644
--- a/app/lib/activitypub/activity/move.rb
+++ b/app/lib/activitypub/activity/move.rb
@@ -4,9 +4,8 @@ class ActivityPub::Activity::Move < ActivityPub::Activity
   PROCESSING_COOLDOWN = 7.days.seconds
 
   def perform
-    return if origin_account.uri != object_uri || processed?
-
-    mark_as_processing!
+    return if origin_account.uri != object_uri
+    return unless mark_as_processing!
 
     target_account = ActivityPub::FetchRemoteAccountService.new.call(target_uri)
 
@@ -35,12 +34,8 @@ class ActivityPub::Activity::Move < ActivityPub::Activity
     value_or_id(@json['target'])
   end
 
-  def processed?
-    redis.exists?("move_in_progress:#{@account.id}")
-  end
-
   def mark_as_processing!
-    redis.setex("move_in_progress:#{@account.id}", PROCESSING_COOLDOWN, true)
+    redis.set("move_in_progress:#{@account.id}", true, nx: true, ex: PROCESSING_COOLDOWN)
   end
 
   def unmark_as_processing!
diff --git a/app/lib/activitypub/tag_manager.rb b/app/lib/activitypub/tag_manager.rb
index 3f2ae1106..f6b9741fa 100644
--- a/app/lib/activitypub/tag_manager.rb
+++ b/app/lib/activitypub/tag_manager.rb
@@ -12,6 +12,10 @@ class ActivityPub::TagManager
     public: 'https://www.w3.org/ns/activitystreams#Public',
   }.freeze
 
+  def public_collection?(uri)
+    uri == COLLECTIONS[:public] || uri == 'as:Public' || uri == 'Public'
+  end
+
   def url_for(target)
     return target.url if target.respond_to?(:local?) && !target.local?
 
@@ -60,6 +64,10 @@ class ActivityPub::TagManager
     account_status_replies_url(target.account, target, page_params)
   end
 
+  def followers_uri_for(target)
+    target.local? ? account_followers_url(target) : target.followers_url.presence
+  end
+
   # Primary audience of a status
   # Public statuses go out to primarily the public collection
   # Unlisted and private statuses go out primarily to the followers collection
@@ -76,17 +84,17 @@ class ActivityPub::TagManager
         account_ids = status.active_mentions.pluck(:account_id)
         to = status.account.followers.where(id: account_ids).each_with_object([]) do |account, result|
           result << uri_for(account)
-          result << account_followers_url(account) if account.group?
+          result << followers_uri_for(account) if account.group?
         end
         to.concat(FollowRequest.where(target_account_id: status.account_id, account_id: account_ids).each_with_object([]) do |request, result|
           result << uri_for(request.account)
-          result << account_followers_url(request.account) if request.account.group?
-        end)
+          result << followers_uri_for(request.account) if request.account.group?
+        end).compact
       else
         status.active_mentions.each_with_object([]) do |mention, result|
           result << uri_for(mention.account)
-          result << account_followers_url(mention.account) if mention.account.group?
-        end
+          result << followers_uri_for(mention.account) if mention.account.group?
+        end.compact
       end
     end
   end
@@ -114,17 +122,17 @@ class ActivityPub::TagManager
         account_ids = status.active_mentions.pluck(:account_id)
         cc.concat(status.account.followers.where(id: account_ids).each_with_object([]) do |account, result|
           result << uri_for(account)
-          result << account_followers_url(account) if account.group?
-        end)
+          result << followers_uri_for(account) if account.group?
+        end.compact)
         cc.concat(FollowRequest.where(target_account_id: status.account_id, account_id: account_ids).each_with_object([]) do |request, result|
           result << uri_for(request.account)
-          result << account_followers_url(request.account) if request.account.group?
-        end)
+          result << followers_uri_for(request.account) if request.account.group?
+        end.compact)
       else
         cc.concat(status.active_mentions.each_with_object([]) do |mention, result|
           result << uri_for(mention.account)
-          result << account_followers_url(mention.account) if mention.account.group?
-        end)
+          result << followers_uri_for(mention.account) if mention.account.group?
+        end.compact)
       end
     end
 
diff --git a/app/lib/application_extension.rb b/app/lib/application_extension.rb
index 1d80b8c6d..e61cd0721 100644
--- a/app/lib/application_extension.rb
+++ b/app/lib/application_extension.rb
@@ -4,6 +4,8 @@ module ApplicationExtension
   extend ActiveSupport::Concern
 
   included do
-    validates :website, url: true, if: :website?
+    validates :name, length: { maximum: 60 }
+    validates :website, url: true, length: { maximum: 2_000 }, if: :website?
+    validates :redirect_uri, length: { maximum: 2_000 }
   end
 end
diff --git a/app/lib/exceptions.rb b/app/lib/exceptions.rb
index 7c8e77871..eb472abaa 100644
--- a/app/lib/exceptions.rb
+++ b/app/lib/exceptions.rb
@@ -12,7 +12,11 @@ module Mastodon
   class RateLimitExceededError < Error; end
 
   class UnexpectedResponseError < Error
+    attr_reader :response
+
     def initialize(response = nil)
+      @response = response
+
       if response.respond_to? :uri
         super("#{response.uri} returned code #{response.code}")
       else
diff --git a/app/lib/feed_manager.rb b/app/lib/feed_manager.rb
index 8fa2bb543..2109e63a6 100644
--- a/app/lib/feed_manager.rb
+++ b/app/lib/feed_manager.rb
@@ -192,6 +192,36 @@ class FeedManager
     end
   end
 
+  # Clear all statuses from or mentioning target_account from a list feed
+  # @param [List] list
+  # @param [Account] target_account
+  # @return [void]
+  def clear_from_list(list, target_account)
+    timeline_key        = key(:list, list.id)
+    timeline_status_ids = redis.zrange(timeline_key, 0, -1)
+    statuses            = Status.where(id: timeline_status_ids).select(:id, :reblog_of_id, :account_id).to_a
+    reblogged_ids       = Status.where(id: statuses.map(&:reblog_of_id).compact, account: target_account).pluck(:id)
+    with_mentions_ids   = Mention.active.where(status_id: statuses.flat_map { |s| [s.id, s.reblog_of_id] }.compact, account: target_account).pluck(:status_id)
+
+    target_statuses = statuses.select do |status|
+      status.account_id == target_account.id || reblogged_ids.include?(status.reblog_of_id) || with_mentions_ids.include?(status.id) || with_mentions_ids.include?(status.reblog_of_id)
+    end
+
+    target_statuses.each do |status|
+      unpush_from_list(list, status)
+    end
+  end
+
+  # Clear all statuses from or mentioning target_account from an account's lists
+  # @param [Account] account
+  # @param [Account] target_account
+  # @return [void]
+  def clear_from_lists(account, target_account)
+    List.where(account: account).each do |list|
+      clear_from_list(list, target_account)
+    end
+  end
+
   # Populate home feed of account from scratch
   # @param [Account] account
   # @return [void]
diff --git a/app/lib/video_metadata_extractor.rb b/app/lib/video_metadata_extractor.rb
new file mode 100644
index 000000000..03e40f923
--- /dev/null
+++ b/app/lib/video_metadata_extractor.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+class VideoMetadataExtractor
+  attr_reader :duration, :bitrate, :video_codec, :audio_codec,
+              :colorspace, :width, :height, :frame_rate
+
+  def initialize(path)
+    @path     = path
+    @metadata = Oj.load(ffmpeg_command_output, mode: :strict, symbol_keys: true)
+
+    parse_metadata
+  rescue Terrapin::ExitStatusError, Oj::ParseError
+    @invalid = true
+  rescue Terrapin::CommandNotFoundError
+    raise Paperclip::Errors::CommandNotFoundError, 'Could not run the `ffprobe` command. Please install ffmpeg.'
+  end
+
+  def valid?
+    !@invalid
+  end
+
+  private
+
+  def ffmpeg_command_output
+    command = Terrapin::CommandLine.new('ffprobe', '-i :path -print_format :format -show_format -show_streams -show_error -loglevel :loglevel')
+    command.run(path: @path, format: 'json', loglevel: 'fatal')
+  end
+
+  def parse_metadata
+    if @metadata.key?(:format)
+      @duration = @metadata[:format][:duration].to_f
+      @bitrate  = @metadata[:format][:bit_rate].to_i
+    end
+
+    if @metadata.key?(:streams)
+      video_streams = @metadata[:streams].select { |stream| stream[:codec_type] == 'video' }
+      audio_streams = @metadata[:streams].select { |stream| stream[:codec_type] == 'audio' }
+
+      if (video_stream = video_streams.first)
+        @video_codec = video_stream[:codec_name]
+        @colorspace  = video_stream[:pix_fmt]
+        @width       = video_stream[:width]
+        @height      = video_stream[:height]
+        @frame_rate  = video_stream[:avg_frame_rate] == '0/0' ? nil : Rational(video_stream[:avg_frame_rate])
+      end
+
+      if (audio_stream = audio_streams.first)
+        @audio_codec = audio_stream[:codec_name]
+      end
+    end
+
+    @invalid = true if @metadata.key?(:error)
+  end
+end
diff --git a/app/lib/webfinger.rb b/app/lib/webfinger.rb
index c7aa43bb3..06fac8c37 100644
--- a/app/lib/webfinger.rb
+++ b/app/lib/webfinger.rb
@@ -46,7 +46,9 @@ class Webfinger
   def body_from_webfinger(url = standard_url, use_fallback = true)
     webfinger_request(url).perform do |res|
       if res.code == 200
-        res.body_with_limit
+        body = res.body_with_limit
+        raise Webfinger::Error, "Request for #{@uri} returned empty response" if body.empty?
+        body
       elsif res.code == 404 && use_fallback
         body_from_host_meta
       elsif res.code == 410
diff --git a/app/models/account.rb b/app/models/account.rb
index e6cf03fa8..089727529 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -55,8 +55,9 @@
 #
 
 class Account < ApplicationRecord
-  USERNAME_RE = /[a-z0-9_]+([a-z0-9_\.-]+[a-z0-9_]+)?/i
-  MENTION_RE  = /(?<=^|[^\/[:word:]])@((#{USERNAME_RE})(?:@[[:word:]\.\-]+[a-z0-9]+)?)/i
+  USERNAME_RE   = /[a-z0-9_]+([a-z0-9_\.-]+[a-z0-9_]+)?/i
+  MENTION_RE    = /(?<=^|[^\/[:word:]])@((#{USERNAME_RE})(?:@[[:word:]\.\-]+[[:word:]]+)?)/i
+  URL_PREFIX_RE = /\Ahttp(s?):\/\/[^\/]+/
 
   include AccountAssociations
   include AccountAvatar
@@ -301,7 +302,11 @@ class Account < ApplicationRecord
   end
 
   def fields
-    (self[:fields] || []).map { |f| Field.new(self, f) }
+    (self[:fields] || []).map do |f|
+      Field.new(self, f)
+    rescue
+      nil
+    end.compact
   end
 
   def fields_attributes=(attributes)
@@ -381,7 +386,7 @@ class Account < ApplicationRecord
   def synchronization_uri_prefix
     return 'local' if local?
 
-    @synchronization_uri_prefix ||= uri[/http(s?):\/\/[^\/]+\//]
+    @synchronization_uri_prefix ||= "#{uri[URL_PREFIX_RE]}/"
   end
 
   class Field < ActiveModelSerializers::Model
diff --git a/app/models/account_migration.rb b/app/models/account_migration.rb
index 4fae98ed7..ded32c9c6 100644
--- a/app/models/account_migration.rb
+++ b/app/models/account_migration.rb
@@ -14,6 +14,8 @@
 #
 
 class AccountMigration < ApplicationRecord
+  include Redisable
+
   COOLDOWN_PERIOD = 30.days.freeze
 
   belongs_to :account
@@ -39,7 +41,13 @@ class AccountMigration < ApplicationRecord
 
     return false unless errors.empty?
 
-    save
+    RedisLock.acquire(lock_options) do |lock|
+      if lock.acquired?
+        save
+      else
+        raise Mastodon::RaceConditionError
+      end
+    end
   end
 
   def cooldown_at
@@ -75,4 +83,8 @@ class AccountMigration < ApplicationRecord
   def validate_migration_cooldown
     errors.add(:base, I18n.t('migrations.errors.on_cooldown')) if account.migrations.within_cooldown.exists?
   end
+
+  def lock_options
+    { redis: redis, key: "account_migration:#{account.id}" }
+  end
 end
diff --git a/app/models/account_note.rb b/app/models/account_note.rb
index bf61df923..b338bc92f 100644
--- a/app/models/account_note.rb
+++ b/app/models/account_note.rb
@@ -17,4 +17,5 @@ class AccountNote < ApplicationRecord
   belongs_to :target_account, class_name: 'Account'
 
   validates :account_id, uniqueness: { scope: :target_account_id }
+  validates :comment, length: { maximum: 2_000 }
 end
diff --git a/app/models/concerns/account_finder_concern.rb b/app/models/concerns/account_finder_concern.rb
index 04b2c981b..0dadddad1 100644
--- a/app/models/concerns/account_finder_concern.rb
+++ b/app/models/concerns/account_finder_concern.rb
@@ -14,6 +14,8 @@ module AccountFinderConcern
 
     def representative
       Account.find(-99)
+    rescue ActiveRecord::RecordNotFound
+      Account.create!(id: -99, actor_type: 'Application', locked: true, username: Rails.configuration.x.local_domain)
     end
 
     def find_local(username)
diff --git a/app/models/concerns/account_interactions.rb b/app/models/concerns/account_interactions.rb
index 974f57820..b6439a53e 100644
--- a/app/models/concerns/account_interactions.rb
+++ b/app/models/concerns/account_interactions.rb
@@ -243,10 +243,13 @@ module AccountInteractions
          .where('users.current_sign_in_at > ?', User::ACTIVE_DURATION.ago)
   end
 
-  def remote_followers_hash(url_prefix)
-    Rails.cache.fetch("followers_hash:#{id}:#{url_prefix}") do
+  def remote_followers_hash(url)
+    url_prefix = url[Account::URL_PREFIX_RE]
+    return if url_prefix.blank?
+
+    Rails.cache.fetch("followers_hash:#{id}:#{url_prefix}/") do
       digest = "\x00" * 32
-      followers.where(Account.arel_table[:uri].matches(url_prefix + '%', false, true)).pluck_each(:uri) do |uri|
+      followers.where(Account.arel_table[:uri].matches("#{Account.sanitize_sql_like(url_prefix)}/%", false, true)).or(followers.where(uri: url_prefix)).pluck_each(:uri) do |uri|
         Xorcist.xor!(digest, Digest::SHA256.digest(uri))
       end
       digest.unpack('H*')[0]
diff --git a/app/models/concerns/expireable.rb b/app/models/concerns/expireable.rb
index a66a4661b..4d902abcb 100644
--- a/app/models/concerns/expireable.rb
+++ b/app/models/concerns/expireable.rb
@@ -17,7 +17,7 @@ module Expireable
     end
 
     def expires_in=(interval)
-      self.expires_at = interval.to_i.seconds.from_now if interval.present?
+      self.expires_at = interval.present? ? interval.to_i.seconds.from_now : nil 
       @expires_in     = interval
     end
 
diff --git a/app/models/concerns/omniauthable.rb b/app/models/concerns/omniauthable.rb
index 4ea219537..d6b414148 100644
--- a/app/models/concerns/omniauthable.rb
+++ b/app/models/concerns/omniauthable.rb
@@ -68,7 +68,6 @@ module Omniauthable
     def user_params_from_auth(email, auth)
       {
         email: email || "#{TEMP_EMAIL_PREFIX}-#{auth.uid}-#{auth.provider}.com",
-        password: Devise.friendly_token[0, 20],
         agreement: true,
         external: true,
         account_attributes: {
diff --git a/app/models/follow_request.rb b/app/models/follow_request.rb
index 59fefcdf6..0b6f7629a 100644
--- a/app/models/follow_request.rb
+++ b/app/models/follow_request.rb
@@ -29,7 +29,7 @@ class FollowRequest < ApplicationRecord
   validates :account_id, uniqueness: { scope: :target_account_id }
 
   def authorize!
-    account.follow!(target_account, reblogs: show_reblogs, notify: notify, uri: uri)
+    account.follow!(target_account, reblogs: show_reblogs, notify: notify, uri: uri, bypass_limit: true)
     MergeWorker.perform_async(target_account.id, account.id) if account.local?
     destroy!
   end
diff --git a/app/models/media_attachment.rb b/app/models/media_attachment.rb
index 663bb0896..87e590b2d 100644
--- a/app/models/media_attachment.rb
+++ b/app/models/media_attachment.rb
@@ -287,7 +287,7 @@ class MediaAttachment < ApplicationRecord
       if instance.file_content_type == 'image/gif'
         [:gif_transcoder, :blurhash_transcoder]
       elsif VIDEO_MIME_TYPES.include?(instance.file_content_type)
-        [:video_transcoder, :blurhash_transcoder, :type_corrector]
+        [:transcoder, :blurhash_transcoder, :type_corrector]
       elsif AUDIO_MIME_TYPES.include?(instance.file_content_type)
         [:image_extractor, :transcoder, :type_corrector]
       else
@@ -388,7 +388,7 @@ class MediaAttachment < ApplicationRecord
   # paths but ultimately the same file, so it makes sense to memoize the
   # result while disregarding the path
   def ffmpeg_data(path = nil)
-    @ffmpeg_data ||= FFMPEG::Movie.new(path)
+    @ffmpeg_data ||= VideoMetadataExtractor.new(path)
   end
 
   def enqueue_processing
diff --git a/app/models/status.rb b/app/models/status.rb
index b426f9d5b..b713626c2 100644
--- a/app/models/status.rb
+++ b/app/models/status.rb
@@ -114,7 +114,7 @@ class Status < ApplicationRecord
                    :tags,
                    :preview_cards,
                    :preloadable_poll,
-                   account: :account_stat,
+                   account: [:account_stat, :user],
                    active_mentions: { account: :account_stat },
                    reblog: [
                      :application,
@@ -124,7 +124,7 @@ class Status < ApplicationRecord
                      :conversation,
                      :status_stat,
                      :preloadable_poll,
-                     account: :account_stat,
+                     account: [:account_stat, :user],
                      active_mentions: { account: :account_stat },
                    ],
                    thread: { account: :account_stat }
@@ -301,7 +301,7 @@ class Status < ApplicationRecord
 
       return if account_ids.empty?
 
-      accounts = Account.where(id: account_ids).includes(:account_stat).each_with_object({}) { |a, h| h[a.id] = a }
+      accounts = Account.where(id: account_ids).includes(:account_stat, :user).index_by(&:id)
 
       cached_items.each do |item|
         item.account = accounts[item.account_id]
@@ -422,7 +422,7 @@ class Status < ApplicationRecord
   end
 
   def decrement_counter_caches
-    return if direct_visibility?
+    return if direct_visibility? || new_record?
 
     account&.decrement_count!(:statuses_count)
     reblog&.decrement_count!(:reblogs_count) if reblog?
diff --git a/app/models/user.rb b/app/models/user.rb
index f8c8a6ab5..a38362e57 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -63,7 +63,7 @@ class User < ApplicationRecord
   devise :two_factor_backupable,
          otp_number_of_backup_codes: 10
 
-  devise :registerable, :recoverable, :rememberable, :validatable,
+  devise :registerable, :recoverable, :validatable,
          :confirmable
 
   include Omniauthable
@@ -152,7 +152,7 @@ class User < ApplicationRecord
 
   def confirm
     new_user      = !confirmed?
-    self.approved = true if open_registrations?
+    self.approved = true if open_registrations? && !sign_up_from_ip_requires_approval?
 
     super
 
@@ -468,7 +468,7 @@ class User < ApplicationRecord
   end
 
   def validate_email_dns?
-    email_changed? && !(Rails.env.test? || Rails.env.development?)
+    email_changed? && !external? && !(Rails.env.test? || Rails.env.development?)
   end
 
   def invite_text_required?
diff --git a/app/serializers/manifest_serializer.rb b/app/serializers/manifest_serializer.rb
index dafe8f55b..4786aa760 100644
--- a/app/serializers/manifest_serializer.rb
+++ b/app/serializers/manifest_serializer.rb
@@ -48,7 +48,7 @@ class ManifestSerializer < ActiveModel::Serializer
   end
 
   def scope
-    root_url
+    '/'
   end
 
   def share_target
diff --git a/app/services/activitypub/process_account_service.rb b/app/services/activitypub/process_account_service.rb
index 77b5d1a4b..154fbd213 100644
--- a/app/services/activitypub/process_account_service.rb
+++ b/app/services/activitypub/process_account_service.rb
@@ -283,7 +283,7 @@ class ActivityPub::ProcessAccountService < BaseService
   end
 
   def lock_options
-    { redis: Redis.current, key: "process_account:#{@uri}" }
+    { redis: Redis.current, key: "process_account:#{@uri}", autorelease: 15.minutes.seconds }
   end
 
   def process_tags
diff --git a/app/services/after_block_service.rb b/app/services/after_block_service.rb
index 314919df8..899e84be4 100644
--- a/app/services/after_block_service.rb
+++ b/app/services/after_block_service.rb
@@ -6,6 +6,7 @@ class AfterBlockService < BaseService
     @target_account = target_account
 
     clear_home_feed!
+    clear_list_feeds!
     clear_notifications!
     clear_conversations!
   end
@@ -16,6 +17,10 @@ class AfterBlockService < BaseService
     FeedManager.instance.clear_from_home(@account, @target_account)
   end
 
+  def clear_list_feeds!
+    FeedManager.instance.clear_from_lists(@account, @target_account)
+  end
+
   def clear_conversations!
     AccountConversation.where(account: @account).where('? = ANY(participant_account_ids)', @target_account.id).in_batches.destroy_all
   end
diff --git a/app/services/fetch_link_card_service.rb b/app/services/fetch_link_card_service.rb
index 7efa31054..661641070 100644
--- a/app/services/fetch_link_card_service.rb
+++ b/app/services/fetch_link_card_service.rb
@@ -174,6 +174,6 @@ class FetchLinkCardService < BaseService
   end
 
   def lock_options
-    { redis: Redis.current, key: "fetch:#{@url}" }
+    { redis: Redis.current, key: "fetch:#{@url}", autorelease: 15.minutes.seconds }
   end
 end
diff --git a/app/services/fetch_oembed_service.rb b/app/services/fetch_oembed_service.rb
index 67e33875c..38ad3b989 100644
--- a/app/services/fetch_oembed_service.rb
+++ b/app/services/fetch_oembed_service.rb
@@ -2,6 +2,7 @@
 
 class FetchOEmbedService
   ENDPOINT_CACHE_EXPIRES_IN = 24.hours.freeze
+  URL_REGEX                 = /(=(http[s]?(%3A|:)(\/\/|%2F%2F)))([^&]*)/i.freeze
 
   attr_reader :url, :options, :format, :endpoint_url
 
@@ -55,10 +56,12 @@ class FetchOEmbedService
   end
 
   def cache_endpoint!
+    return unless URL_REGEX.match?(@endpoint_url)
+
     url_domain = Addressable::URI.parse(@url).normalized_host
 
     endpoint_hash = {
-      endpoint: @endpoint_url.gsub(/(=(http[s]?(%3A|:)(\/\/|%2F%2F)))([^&]*)/i, '={url}'),
+      endpoint: @endpoint_url.gsub(URL_REGEX, '={url}'),
       format: @format,
     }
 
diff --git a/app/services/notify_service.rb b/app/services/notify_service.rb
index fc187db40..e78c74d1e 100644
--- a/app/services/notify_service.rb
+++ b/app/services/notify_service.rb
@@ -67,8 +67,49 @@ class NotifyService < BaseService
     message? && @notification.target_status.direct_visibility?
   end
 
+  # Returns true if the sender has been mentionned by the recipient up the thread
   def response_to_recipient?
-    @notification.target_status.in_reply_to_account_id == @recipient.id && @notification.target_status.thread&.direct_visibility?
+    return false if @notification.target_status.in_reply_to_id.nil?
+
+    # Using an SQL CTE to avoid unneeded back-and-forth with SQL server in case of long threads
+    !Status.count_by_sql([<<-SQL.squish, id: @notification.target_status.in_reply_to_id, recipient_id: @recipient.id, sender_id: @notification.from_account.id]).zero?
+      WITH RECURSIVE ancestors(id, in_reply_to_id, replying_to_sender) AS (
+          SELECT
+            s.id, s.in_reply_to_id, (CASE
+              WHEN s.account_id = :recipient_id THEN
+                EXISTS (
+                  SELECT *
+                  FROM mentions m
+                  WHERE m.silent = FALSE AND m.account_id = :sender_id AND m.status_id = s.id
+                )
+              ELSE
+                FALSE
+             END)
+          FROM statuses s
+          WHERE s.id = :id
+        UNION ALL
+          SELECT
+            s.id,
+            s.in_reply_to_id,
+            (CASE
+              WHEN s.account_id = :recipient_id THEN
+                EXISTS (
+                  SELECT *
+                  FROM mentions m
+                  WHERE m.silent = FALSE AND m.account_id = :sender_id AND m.status_id = s.id
+                )
+              ELSE
+                FALSE
+             END)
+          FROM ancestors st
+          JOIN statuses s ON s.id = st.in_reply_to_id
+          WHERE st.replying_to_sender IS FALSE
+      )
+      SELECT COUNT(*)
+      FROM ancestors st
+      JOIN statuses s ON s.id = st.id
+      WHERE st.replying_to_sender IS TRUE AND s.visibility = 3
+    SQL
   end
 
   def from_staff?
diff --git a/app/services/post_status_service.rb b/app/services/post_status_service.rb
index 0a383d6a3..85aaec4d6 100644
--- a/app/services/post_status_service.rb
+++ b/app/services/post_status_service.rb
@@ -74,6 +74,9 @@ class PostStatusService < BaseService
     status_for_validation = @account.statuses.build(status_attributes)
 
     if status_for_validation.valid?
+      # Marking the status as destroyed is necessary to prevent the status from being
+      # persisted when the associated media attachments get updated when creating the
+      # scheduled status.
       status_for_validation.destroy
 
       # The following transaction block is needed to wrap the UPDATEs to
diff --git a/app/services/remove_status_service.rb b/app/services/remove_status_service.rb
index d6043fb5d..e17b77377 100644
--- a/app/services/remove_status_service.rb
+++ b/app/services/remove_status_service.rb
@@ -16,6 +16,8 @@ class RemoveStatusService < BaseService
     @account  = status.account
     @options  = options
 
+    @status.discard
+
     RedisLock.acquire(lock_options) do |lock|
       if lock.acquired?
         remove_from_self if @account.local?
@@ -168,6 +170,6 @@ class RemoveStatusService < BaseService
   end
 
   def lock_options
-    { redis: Redis.current, key: "distribute:#{@status.id}" }
+    { redis: Redis.current, key: "distribute:#{@status.id}", autorelease: 5.minutes.seconds }
   end
 end
diff --git a/app/services/report_service.rb b/app/services/report_service.rb
index 9d9c7d6c9..bc0a8b464 100644
--- a/app/services/report_service.rb
+++ b/app/services/report_service.rb
@@ -10,6 +10,8 @@ class ReportService < BaseService
     @comment        = options.delete(:comment) || ''
     @options        = options
 
+    raise ActiveRecord::RecordNotFound if @target_account.suspended?
+
     create_report!
     notify_staff!
     forward_to_origin! if !@target_account.local? && ActiveModel::Type::Boolean.new.cast(@options[:forward])
diff --git a/app/services/resolve_account_service.rb b/app/services/resolve_account_service.rb
index 3301aaf51..de7aabc66 100644
--- a/app/services/resolve_account_service.rb
+++ b/app/services/resolve_account_service.rb
@@ -141,10 +141,11 @@ class ResolveAccountService < BaseService
   end
 
   def queue_deletion!
+    @account.suspend!(origin: :remote)
     AccountDeletionWorker.perform_async(@account.id, reserve_username: false, skip_activitypub: true)
   end
 
   def lock_options
-    { redis: Redis.current, key: "resolve:#{@username}@#{@domain}" }
+    { redis: Redis.current, key: "resolve:#{@username}@#{@domain}", autorelease: 15.minutes.seconds }
   end
 end
diff --git a/app/services/suspend_account_service.rb b/app/services/suspend_account_service.rb
index 9f4da91d4..b8dc8d5e0 100644
--- a/app/services/suspend_account_service.rb
+++ b/app/services/suspend_account_service.rb
@@ -42,7 +42,13 @@ class SuspendAccountService < BaseService
   end
 
   def distribute_update_actor!
-    ActivityPub::UpdateDistributionWorker.perform_async(@account.id) if @account.local?
+    return unless @account.local?
+
+    account_reach_finder = AccountReachFinder.new(@account)
+
+    ActivityPub::DeliveryWorker.push_bulk(account_reach_finder.inboxes) do |inbox_url|
+      [signed_activity_json, @account.id, inbox_url]
+    end
   end
 
   def unmerge_from_home_timelines!
@@ -90,4 +96,8 @@ class SuspendAccountService < BaseService
       end
     end
   end
+
+  def signed_activity_json
+    @signed_activity_json ||= Oj.dump(serialize_payload(@account, ActivityPub::UpdateSerializer, signer: @account))
+  end
 end
diff --git a/app/services/unsuspend_account_service.rb b/app/services/unsuspend_account_service.rb
index ce9ee48ed..7e52a7594 100644
--- a/app/services/unsuspend_account_service.rb
+++ b/app/services/unsuspend_account_service.rb
@@ -7,11 +7,12 @@ class UnsuspendAccountService < BaseService
     unsuspend!
     refresh_remote_account!
 
-    return if @account.nil?
+    return if @account.nil? || @account.suspended?
 
     merge_into_home_timelines!
     merge_into_list_timelines!
     publish_media_attachments!
+    distribute_update_actor!
   end
 
   private
@@ -36,6 +37,16 @@ class UnsuspendAccountService < BaseService
     # @account would now be nil.
   end
 
+  def distribute_update_actor!
+    return unless @account.local?
+
+    account_reach_finder = AccountReachFinder.new(@account)
+
+    ActivityPub::DeliveryWorker.push_bulk(account_reach_finder.inboxes) do |inbox_url|
+      [signed_activity_json, @account.id, inbox_url]
+    end
+  end
+
   def merge_into_home_timelines!
     @account.followers_for_local_distribution.find_each do |follower|
       FeedManager.instance.merge_into_home(@account, follower)
@@ -81,4 +92,8 @@ class UnsuspendAccountService < BaseService
       end
     end
   end
+
+  def signed_activity_json
+    @signed_activity_json ||= Oj.dump(serialize_payload(@account, ActivityPub::UpdateSerializer, signer: @account))
+  end
 end
diff --git a/app/views/filters/_fields.html.haml b/app/views/filters/_fields.html.haml
index fb94a07fc..84dcdcca5 100644
--- a/app/views/filters/_fields.html.haml
+++ b/app/views/filters/_fields.html.haml
@@ -2,7 +2,7 @@
   .fields-row__column.fields-row__column-6.fields-group
     = f.input :phrase, as: :string, wrapper: :with_label, hint: false
   .fields-row__column.fields-row__column-6.fields-group
-    = f.input :expires_in, wrapper: :with_label, collection: [30.minutes, 1.hour, 6.hours, 12.hours, 1.day, 1.week].map(&:to_i), label_method: lambda { |i| I18n.t("invites.expires_in.#{i}") }, prompt: I18n.t('invites.expires_in_prompt')
+    = f.input :expires_in, wrapper: :with_label, collection: [30.minutes, 1.hour, 6.hours, 12.hours, 1.day, 1.week].map(&:to_i), label_method: lambda { |i| I18n.t("invites.expires_in.#{i}") }, include_blank: I18n.t('invites.expires_in_prompt')
 
 .fields-group
   = f.input :context, wrapper: :with_block_label, collection: CustomFilter::VALID_CONTEXTS, as: :check_boxes, collection_wrapper_tag: 'ul', item_wrapper_tag: 'li', label_method: lambda { |context| I18n.t("filters.contexts.#{context}") }, include_blank: false
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 9501207e0..436024ee3 100755
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -31,7 +31,7 @@
     = stylesheet_link_tag '/inert.css', skip_pipeline: true, media: 'all', id: 'inert-style'
 
     - if Setting.custom_css.present?
-      = stylesheet_link_tag custom_css_path, media: 'all'
+      = stylesheet_link_tag custom_css_path, host: request.host, media: 'all'
 
     = yield :header_tags
 
diff --git a/app/workers/activitypub/delivery_worker.rb b/app/workers/activitypub/delivery_worker.rb
index 6c5a576a7..788f2cf80 100644
--- a/app/workers/activitypub/delivery_worker.rb
+++ b/app/workers/activitypub/delivery_worker.rb
@@ -44,11 +44,7 @@ class ActivityPub::DeliveryWorker
   end
 
   def synchronization_header
-    "collectionId=\"#{account_followers_url(@source_account)}\", digest=\"#{@source_account.remote_followers_hash(inbox_url_prefix)}\", url=\"#{account_followers_synchronization_url(@source_account)}\""
-  end
-
-  def inbox_url_prefix
-    @inbox_url[/http(s?):\/\/[^\/]+\//]
+    "collectionId=\"#{account_followers_url(@source_account)}\", digest=\"#{@source_account.remote_followers_hash(@inbox_url)}\", url=\"#{account_followers_synchronization_url(@source_account)}\""
   end
 
   def perform_request
diff --git a/app/workers/distribution_worker.rb b/app/workers/distribution_worker.rb
index 4e20ef31b..e85cd7e95 100644
--- a/app/workers/distribution_worker.rb
+++ b/app/workers/distribution_worker.rb
@@ -4,7 +4,7 @@ class DistributionWorker
   include Sidekiq::Worker
 
   def perform(status_id)
-    RedisLock.acquire(redis: Redis.current, key: "distribute:#{status_id}") do |lock|
+    RedisLock.acquire(redis: Redis.current, key: "distribute:#{status_id}", autorelease: 5.minutes.seconds) do |lock|
       if lock.acquired?
         FanOutOnWriteService.new.call(Status.find(status_id))
       else
diff --git a/app/workers/move_worker.rb b/app/workers/move_worker.rb
index 39e321316..4a900e3b8 100644
--- a/app/workers/move_worker.rb
+++ b/app/workers/move_worker.rb
@@ -13,9 +13,13 @@ class MoveWorker
       queue_follow_unfollows!
     end
 
+    @deferred_error = nil
+
     copy_account_notes!
     carry_blocks_over!
     carry_mutes_over!
+
+    raise @deferred_error unless @deferred_error.nil?
   rescue ActiveRecord::RecordNotFound
     true
   end
@@ -36,21 +40,31 @@ class MoveWorker
 
     @source_account.followers.local.select(:id).find_in_batches do |accounts|
       UnfollowFollowWorker.push_bulk(accounts.map(&:id)) { |follower_id| [follower_id, @source_account.id, @target_account.id, bypass_locked] }
+    rescue => e
+      @deferred_error = e
     end
   end
 
   def copy_account_notes!
     AccountNote.where(target_account: @source_account).find_each do |note|
-      text = I18n.with_locale(note.account.user.locale || I18n.default_locale) do
+      text = I18n.with_locale(note.account.user&.locale || I18n.default_locale) do
         I18n.t('move_handler.copy_account_note_text', acct: @source_account.acct)
       end
 
       new_note = AccountNote.find_by(account: note.account, target_account: @target_account)
       if new_note.nil?
-        AccountNote.create!(account: note.account, target_account: @target_account, comment: [text, note.comment].join('\n'))
+        begin
+          AccountNote.create!(account: note.account, target_account: @target_account, comment: [text, note.comment].join("\n"))
+        rescue ActiveRecord::RecordInvalid
+          AccountNote.create!(account: note.account, target_account: @target_account, comment: note.comment)
+        end
       else
-        new_note.update!(comment: [text, note.comment, '\n', new_note.comment].join('\n'))
+        new_note.update!(comment: [text, note.comment, "\n", new_note.comment].join("\n"))
       end
+    rescue ActiveRecord::RecordInvalid
+      nil
+    rescue => e
+      @deferred_error = e
     end
   end
 
@@ -60,6 +74,8 @@ class MoveWorker
         BlockService.new.call(block.account, @target_account)
         add_account_note_if_needed!(block.account, 'move_handler.carry_blocks_over_text')
       end
+    rescue => e
+      @deferred_error = e
     end
   end
 
@@ -67,12 +83,14 @@ class MoveWorker
     @source_account.muted_by_relationships.where(account: Account.local).find_each do |mute|
       MuteService.new.call(mute.account, @target_account, notifications: mute.hide_notifications) unless mute.account.muting?(@target_account) || mute.account.following?(@target_account)
       add_account_note_if_needed!(mute.account, 'move_handler.carry_mutes_over_text')
+    rescue => e
+      @deferred_error = e
     end
   end
 
   def add_account_note_if_needed!(account, id)
     unless AccountNote.where(account: account, target_account: @target_account).exists?
-      text = I18n.with_locale(account.user.locale || I18n.default_locale) do
+      text = I18n.with_locale(account.user&.locale || I18n.default_locale) do
         I18n.t(id, acct: @source_account.acct)
       end
       AccountNote.create!(account: account, target_account: @target_account, comment: text)
diff --git a/app/workers/redownload_media_worker.rb b/app/workers/redownload_media_worker.rb
index 0638cd0f0..343caa32c 100644
--- a/app/workers/redownload_media_worker.rb
+++ b/app/workers/redownload_media_worker.rb
@@ -3,6 +3,7 @@
 class RedownloadMediaWorker
   include Sidekiq::Worker
   include ExponentialBackoff
+  include JsonLdHelper
 
   sidekiq_options queue: 'pull', retry: 3
 
@@ -15,6 +16,14 @@ class RedownloadMediaWorker
     media_attachment.download_thumbnail!
     media_attachment.save
   rescue ActiveRecord::RecordNotFound
-    true
+    # Do nothing
+  rescue Mastodon::UnexpectedResponseError => e
+    response = e.response
+
+    if response_error_unsalvageable?(response)
+      # Give up
+    else
+      raise e
+    end
   end
 end
diff --git a/app/workers/thread_resolve_worker.rb b/app/workers/thread_resolve_worker.rb
index 8bba9ca75..1b77dfdd9 100644
--- a/app/workers/thread_resolve_worker.rb
+++ b/app/workers/thread_resolve_worker.rb
@@ -14,5 +14,7 @@ class ThreadResolveWorker
 
     child_status.thread = parent_status
     child_status.save!
+  rescue ActiveRecord::RecordNotFound
+    true
   end
 end
diff --git a/config/application.rb b/config/application.rb
index af7735221..c9475ba04 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -11,12 +11,12 @@ require_relative '../lib/redis/namespace_extensions'
 require_relative '../lib/paperclip/url_generator_extensions'
 require_relative '../lib/paperclip/attachment_extensions'
 require_relative '../lib/paperclip/media_type_spoof_detector_extensions'
-require_relative '../lib/paperclip/transcoder_extensions'
 require_relative '../lib/paperclip/lazy_thumbnail'
 require_relative '../lib/paperclip/gif_transcoder'
-require_relative '../lib/paperclip/video_transcoder'
+require_relative '../lib/paperclip/transcoder'
 require_relative '../lib/paperclip/type_corrector'
 require_relative '../lib/paperclip/response_with_limit_adapter'
+require_relative '../lib/terrapin/multi_pipe_extensions'
 require_relative '../lib/mastodon/snowflake'
 require_relative '../lib/mastodon/version'
 require_relative '../lib/devise/two_factor_ldap_authenticatable'
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
index ef612e177..5232e6cfd 100644
--- a/config/initializers/devise.rb
+++ b/config/initializers/devise.rb
@@ -1,3 +1,5 @@
+require 'devise/strategies/authenticatable'
+
 Warden::Manager.after_set_user except: :fetch do |user, warden|
   if user.session_active?(warden.cookies.signed['_session_id'] || warden.raw_session['auth_id'])
     session_id = warden.cookies.signed['_session_id'] || warden.raw_session['auth_id']
@@ -72,17 +74,48 @@ module Devise
   mattr_accessor :ldap_uid_conversion_replace
   @@ldap_uid_conversion_replace = nil
 
-  class Strategies::PamAuthenticatable
-    def valid?
-      super && ::Devise.pam_authentication
+  module Strategies
+    class PamAuthenticatable
+      def valid?
+        super && ::Devise.pam_authentication
+      end
+    end
+
+    class SessionActivationRememberable < Authenticatable
+      def valid?
+        @session_cookie = nil
+        session_cookie.present?
+      end
+
+      def authenticate!
+        resource = SessionActivation.find_by(session_id: session_cookie)&.user
+
+        unless resource
+          cookies.delete('_session_id')
+          return pass
+        end
+
+        if validate(resource)
+          success!(resource)
+        end
+      end
+
+      private
+
+      def session_cookie
+        @session_cookie ||= cookies.signed['_session_id']
+      end
     end
   end
 end
 
+Warden::Strategies.add(:session_activation_rememberable, Devise::Strategies::SessionActivationRememberable)
+
 Devise.setup do |config|
   config.warden do |manager|
     manager.default_strategies(scope: :user).unshift :two_factor_ldap_authenticatable if Devise.ldap_authentication
     manager.default_strategies(scope: :user).unshift :two_factor_pam_authenticatable  if Devise.pam_authentication
+    manager.default_strategies(scope: :user).unshift :session_activation_rememberable
     manager.default_strategies(scope: :user).unshift :two_factor_authenticatable
     manager.default_strategies(scope: :user).unshift :two_factor_backupable
   end
diff --git a/config/initializers/doorkeeper.rb b/config/initializers/doorkeeper.rb
index 63cff7c59..f78db8653 100644
--- a/config/initializers/doorkeeper.rb
+++ b/config/initializers/doorkeeper.rb
@@ -52,6 +52,11 @@ Doorkeeper.configure do
   # Issue access tokens with refresh token (disabled by default)
   # use_refresh_token
 
+  # Forbids creating/updating applications with arbitrary scopes that are
+  # not in configuration, i.e. `default_scopes` or `optional_scopes`.
+  # (Disabled by default)
+  enforce_configured_scopes
+
   # Provide support for an owner to be assigned to each registered application (disabled by default)
   # Optional parameter :confirmation => true (default false) if you want to enforce ownership of
   # a registered application
diff --git a/config/initializers/omniauth.rb b/config/initializers/omniauth.rb
index e8d7697a1..9e037f421 100644
--- a/config/initializers/omniauth.rb
+++ b/config/initializers/omniauth.rb
@@ -60,6 +60,7 @@ Devise.setup do |config|
     saml_options[:attribute_statements][:verified] = [ENV['SAML_ATTRIBUTES_STATEMENTS_VERIFIED']] if ENV['SAML_ATTRIBUTES_STATEMENTS_VERIFIED']
     saml_options[:attribute_statements][:verified_email] = [ENV['SAML_ATTRIBUTES_STATEMENTS_VERIFIED_EMAIL']] if ENV['SAML_ATTRIBUTES_STATEMENTS_VERIFIED_EMAIL']
     saml_options[:uid_attribute] = ENV['SAML_UID_ATTRIBUTE'] if ENV['SAML_UID_ATTRIBUTE']
+    saml_options[:allowed_clock_drift] = ENV['SAML_ALLOWED_CLOCK_DRIFT'] if ENV['SAML_ALLOWED_CLOCK_DRIFT']
     config.omniauth :saml, saml_options
   end
 end
diff --git a/db/migrate/20181026034033_remove_faux_remote_account_duplicates.rb b/db/migrate/20181026034033_remove_faux_remote_account_duplicates.rb
index bd4f4c2a3..40537e9c9 100644
--- a/db/migrate/20181026034033_remove_faux_remote_account_duplicates.rb
+++ b/db/migrate/20181026034033_remove_faux_remote_account_duplicates.rb
@@ -1,6 +1,46 @@
 class RemoveFauxRemoteAccountDuplicates < ActiveRecord::Migration[5.2]
   disable_ddl_transaction!
 
+  class StreamEntry < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    belongs_to :account, inverse_of: :stream_entries
+  end
+
+  class Status < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    belongs_to :account, inverse_of: :statuses
+    has_many :favourites, inverse_of: :status, dependent: :destroy
+    has_many :mentions, dependent: :destroy, inverse_of: :status
+  end
+
+  class Favourite < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    belongs_to :account, inverse_of: :favourites
+    belongs_to :status,  inverse_of: :favourites
+  end
+
+  class Mention < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    belongs_to :account, inverse_of: :mentions
+    belongs_to :status
+  end
+
+  class Notification < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    belongs_to :account, optional: true
+    belongs_to :from_account, class_name: 'Account', optional: true
+    belongs_to :activity, polymorphic: true, optional: true
+  end
+
+  class Account < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    has_many :stream_entries, inverse_of: :account, dependent: :destroy
+    has_many :statuses, inverse_of: :account, dependent: :destroy
+    has_many :favourites, inverse_of: :account, dependent: :destroy
+    has_many :mentions, inverse_of: :account, dependent: :destroy
+    has_many :notifications, inverse_of: :account, dependent: :destroy
+  end
+
   def up
     local_domain = Rails.configuration.x.local_domain
 
diff --git a/db/migrate/20190715164535_add_instance_actor.rb b/db/migrate/20190715164535_add_instance_actor.rb
index a26d54949..8c0301d69 100644
--- a/db/migrate/20190715164535_add_instance_actor.rb
+++ b/db/migrate/20190715164535_add_instance_actor.rb
@@ -1,4 +1,9 @@
 class AddInstanceActor < ActiveRecord::Migration[5.2]
+  class Account < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    validates :username, uniqueness: { scope: :domain, case_sensitive: false }
+  end
+
   def up
     Account.create!(id: -99, actor_type: 'Application', locked: true, username: Rails.configuration.x.local_domain)
   end
diff --git a/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb b/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb
index 057fc86ba..ceb8e563b 100644
--- a/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb
+++ b/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb
@@ -15,7 +15,13 @@ class AddCaseInsensitiveIndexToTags < ActiveRecord::Migration[5.2]
       Tag.where(id: redundant_tag_ids).in_batches.delete_all
     end
 
-    safety_assured { execute 'CREATE UNIQUE INDEX CONCURRENTLY index_tags_on_name_lower ON tags (lower(name))' }
+    begin
+      safety_assured { execute 'CREATE UNIQUE INDEX CONCURRENTLY index_tags_on_name_lower ON tags (lower(name))' }
+    rescue ActiveRecord::StatementInvalid
+      remove_index :tags, name: 'index_tags_on_name_lower'
+      raise
+    end
+
     remove_index :tags, name: 'index_tags_on_name'
     remove_index :tags, name: 'hashtag_search_index'
   end
diff --git a/db/migrate/20191007013357_update_pt_locales.rb b/db/migrate/20191007013357_update_pt_locales.rb
index b7288d38a..9e8f8b424 100644
--- a/db/migrate/20191007013357_update_pt_locales.rb
+++ b/db/migrate/20191007013357_update_pt_locales.rb
@@ -1,4 +1,8 @@
 class UpdatePtLocales < ActiveRecord::Migration[5.2]
+  class User < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+  end
+
   disable_ddl_transaction!
 
   def up
diff --git a/db/migrate/20200620164023_add_fixed_lowercase_index_to_accounts.rb b/db/migrate/20200620164023_add_fixed_lowercase_index_to_accounts.rb
index c3aa8e33c..366bf9aa7 100644
--- a/db/migrate/20200620164023_add_fixed_lowercase_index_to_accounts.rb
+++ b/db/migrate/20200620164023_add_fixed_lowercase_index_to_accounts.rb
@@ -1,16 +1,10 @@
+require Rails.root.join('lib', 'mastodon', 'migration_helpers')
+
 class AddFixedLowercaseIndexToAccounts < ActiveRecord::Migration[5.2]
+  include Mastodon::MigrationHelpers
+
   disable_ddl_transaction!
 
-  class CorruptionError < StandardError
-    def cause
-      nil
-    end
-
-    def backtrace
-      []
-    end
-  end
-
   def up
     if index_name_exists?(:accounts, 'old_index_accounts_on_username_and_domain_lower') && index_name_exists?(:accounts, 'index_accounts_on_username_and_domain_lower')
       remove_index :accounts, name: 'index_accounts_on_username_and_domain_lower'
@@ -21,7 +15,8 @@ class AddFixedLowercaseIndexToAccounts < ActiveRecord::Migration[5.2]
     begin
       add_index :accounts, "lower (username), COALESCE(lower(domain), '')", name: 'index_accounts_on_username_and_domain_lower', unique: true, algorithm: :concurrently
     rescue ActiveRecord::RecordNotUnique
-      raise CorruptionError, 'Migration failed because of index corruption, see https://docs.joinmastodon.org/admin/troubleshooting/index-corruption/#fixing'
+      remove_index :accounts, name: 'index_accounts_on_username_and_domain_lower'
+      raise CorruptionError
     end
 
     remove_index :accounts, name: 'old_index_accounts_on_username_and_domain_lower' if index_name_exists?(:accounts, 'old_index_accounts_on_username_and_domain_lower')
diff --git a/docker-compose.yml b/docker-compose.yml
index 52eea7a74..a92b40c22 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -43,7 +43,7 @@ services:
 
   web:
     build: .
-    image: tootsuite/mastodon
+    image: tootsuite/mastodon:v3.3.1
     restart: always
     env_file: .env.production
     command: bash -c "rm -f /mastodon/tmp/pids/server.pid; bundle exec rails s -p 3000"
@@ -63,7 +63,7 @@ services:
 
   streaming:
     build: .
-    image: tootsuite/mastodon
+    image: tootsuite/mastodon:v3.3.1
     restart: always
     env_file: .env.production
     command: node ./streaming
@@ -80,7 +80,7 @@ services:
 
   sidekiq:
     build: .
-    image: tootsuite/mastodon
+    image: tootsuite/mastodon:v3.3.1
     restart: always
     env_file: .env.production
     command: bundle exec sidekiq
diff --git a/lib/cli.rb b/lib/cli.rb
index 3f1658566..8815e137a 100644
--- a/lib/cli.rb
+++ b/lib/cli.rb
@@ -94,17 +94,22 @@ module Mastodon
 
       exit(1) unless prompt.ask('Type in the domain of the server to confirm:', required: true) == Rails.configuration.x.local_domain
 
-      prompt.warn('This operation WILL NOT be reversible. It can also take a long time.')
-      prompt.warn('While the data won\'t be erased locally, the server will be in a BROKEN STATE afterwards.')
-      prompt.warn('A running Sidekiq process is required. Do not shut it down until queues clear.')
+      unless options[:dry_run]
+        prompt.warn('This operation WILL NOT be reversible. It can also take a long time.')
+        prompt.warn('While the data won\'t be erased locally, the server will be in a BROKEN STATE afterwards.')
+        prompt.warn('A running Sidekiq process is required. Do not shut it down until queues clear.')
 
-      exit(1) if prompt.no?('Are you sure you want to proceed?')
+        exit(1) if prompt.no?('Are you sure you want to proceed?')
+      end
 
       inboxes   = Account.inboxes
       processed = 0
       dry_run   = options[:dry_run] ? ' (DRY RUN)' : ''
 
+      Setting.registrations_mode = 'none' unless options[:dry_run]
+
       if inboxes.empty?
+        Account.local.without_suspended.in_batches.update_all(suspended_at: Time.now.utc, suspension_origin: :local) unless options[:dry_run]
         prompt.ok('It seems like your server has not federated with anything')
         prompt.ok('You can shut it down and delete it any time')
         return
@@ -112,9 +117,7 @@ module Mastodon
 
       prompt.warn('Do NOT interrupt this process...')
 
-      Setting.registrations_mode = 'none'
-
-      Account.local.without_suspended.find_each do |account|
+      delete_account = ->(account) do
         payload = ActiveModelSerializers::SerializableResource.new(
           account,
           serializer: ActivityPub::DeleteActorSerializer,
@@ -128,12 +131,15 @@ module Mastodon
             [json, account.id, inbox_url]
           end
 
-          account.suspend!
+          account.suspend!(block_email: false)
         end
 
         processed += 1
       end
 
+      Account.local.without_suspended.find_each { |account| delete_account.call(account) }
+      Account.local.suspended.joins(:deletion_request).find_each { |account| delete_account.call(account) }
+
       prompt.ok("Queued #{inboxes.size * processed} items into Sidekiq for #{processed} accounts#{dry_run}")
       prompt.ok('Wait until Sidekiq processes all items, then you can shut everything down and delete the data')
     rescue TTY::Reader::InputInterrupt
diff --git a/lib/mastodon/accounts_cli.rb b/lib/mastodon/accounts_cli.rb
index 653bfca30..74162256f 100644
--- a/lib/mastodon/accounts_cli.rb
+++ b/lib/mastodon/accounts_cli.rb
@@ -402,7 +402,7 @@ module Mastodon
         exit(1)
       end
 
-      parallelize_with_progress(target_account.followers.local) do |account|
+      processed, = parallelize_with_progress(target_account.followers.local) do |account|
         UnfollowService.new.call(account, target_account)
       end
 
diff --git a/lib/mastodon/emoji_cli.rb b/lib/mastodon/emoji_cli.rb
index da8fd6a0d..5bee70ea5 100644
--- a/lib/mastodon/emoji_cli.rb
+++ b/lib/mastodon/emoji_cli.rb
@@ -43,8 +43,13 @@ module Mastodon
         tar.each do |entry|
           next unless entry.file? && entry.full_name.end_with?('.png')
 
-          shortcode    = [options[:prefix], File.basename(entry.full_name, '.*'), options[:suffix]].compact.join
-          custom_emoji = CustomEmoji.local.find_by(shortcode: shortcode)
+          filename = File.basename(entry.full_name, '.*')
+
+          # Skip macOS shadow files
+          next if filename.start_with?('._')
+
+          shortcode    = [options[:prefix], filename, options[:suffix]].compact.join
+          custom_emoji = CustomEmoji.local.find_by("LOWER(shortcode) = ?", shortcode.downcase)
 
           if custom_emoji && !options[:overwrite]
             skipped += 1
diff --git a/lib/mastodon/maintenance_cli.rb b/lib/mastodon/maintenance_cli.rb
index 822051ceb..9f1eaf263 100644
--- a/lib/mastodon/maintenance_cli.rb
+++ b/lib/mastodon/maintenance_cli.rb
@@ -14,7 +14,7 @@ module Mastodon
     end
 
     MIN_SUPPORTED_VERSION = 2019_10_01_213028
-    MAX_SUPPORTED_VERSION = 2020_12_18_054746
+    MAX_SUPPORTED_VERSION = 2021_03_08_133107
 
     # Stubs to enjoy ActiveRecord queries while not depending on a particular
     # version of the code/database
@@ -142,7 +142,6 @@ module Mastodon
       @prompt.warn 'Please make sure to stop Mastodon and have a backup.'
       exit(1) unless @prompt.yes?('Continue?')
 
-      deduplicate_accounts!
       deduplicate_users!
       deduplicate_account_domain_blocks!
       deduplicate_account_identity_proofs!
@@ -157,9 +156,11 @@ module Mastodon
       deduplicate_media_attachments!
       deduplicate_preview_cards!
       deduplicate_statuses!
+      deduplicate_accounts!
       deduplicate_tags!
       deduplicate_webauthn_credentials!
 
+      Scenic.database.refresh_materialized_view('instances', concurrently: true, cascade: false) if ActiveRecord::Migrator.current_version >= 2020_12_06_004238
       Rails.cache.clear
 
       @prompt.say 'Finished!'
@@ -188,6 +189,11 @@ module Mastodon
       else
         ActiveRecord::Base.connection.add_index :accounts, "lower (username), COALESCE(lower(domain), '')", name: 'index_accounts_on_username_and_domain_lower', unique: true
       end
+
+      @prompt.say 'Reindexing textual indexes on accounts…'
+      ActiveRecord::Base.connection.execute('REINDEX INDEX search_index;')
+      ActiveRecord::Base.connection.execute('REINDEX INDEX index_accounts_on_uri;')
+      ActiveRecord::Base.connection.execute('REINDEX INDEX index_accounts_on_url;')
     end
 
     def deduplicate_users!
diff --git a/lib/mastodon/migration_helpers.rb b/lib/mastodon/migration_helpers.rb
index bf2314ecb..ab2318a72 100644
--- a/lib/mastodon/migration_helpers.rb
+++ b/lib/mastodon/migration_helpers.rb
@@ -41,6 +41,20 @@
 
 module Mastodon
   module MigrationHelpers
+    class CorruptionError < StandardError
+      def initialize(message = nil)
+        super(message.presence || 'Migration failed because of index corruption, see https://docs.joinmastodon.org/admin/troubleshooting/index-corruption/#fixing')
+      end
+
+      def cause
+        nil
+      end
+
+      def backtrace
+        []
+      end
+    end
+
     # Stub for Database.postgresql? from GitLab
     def self.postgresql?
       ActiveRecord::Base.configurations[Rails.env]['adapter'].casecmp('postgresql').zero?
@@ -315,7 +329,7 @@ module Mastodon
       table = Arel::Table.new(table_name)
 
       total = estimate_rows_in_table(table_name).to_i
-      if total == 0
+      if total < 1
         count_arel = table.project(Arel.star.count.as('count'))
         count_arel = yield table, count_arel if block_given?
 
diff --git a/lib/mastodon/version.rb b/lib/mastodon/version.rb
index b7a686198..c2b5379d1 100644
--- a/lib/mastodon/version.rb
+++ b/lib/mastodon/version.rb
@@ -13,7 +13,7 @@ module Mastodon
     end
 
     def patch
-      0
+      1
     end
 
     def flags
diff --git a/lib/paperclip/attachment_extensions.rb b/lib/paperclip/attachment_extensions.rb
index 94f7769b6..2f2656616 100644
--- a/lib/paperclip/attachment_extensions.rb
+++ b/lib/paperclip/attachment_extensions.rb
@@ -2,6 +2,10 @@
 
 module Paperclip
   module AttachmentExtensions
+    def meta
+      instance_read(:meta)
+    end
+
     # We overwrite this method to support delayed processing in
     # Sidekiq. Since we process the original file to reduce disk
     # usage, and we still want to generate thumbnails straight
diff --git a/lib/paperclip/gif_transcoder.rb b/lib/paperclip/gif_transcoder.rb
index 9f3c8e8be..74aa1a0b2 100644
--- a/lib/paperclip/gif_transcoder.rb
+++ b/lib/paperclip/gif_transcoder.rb
@@ -100,7 +100,8 @@ end
 
 module Paperclip
   # This transcoder is only to be used for the MediaAttachment model
-  # to convert animated gifs to webm
+  # to convert animated GIFs to videos
+
   class GifTranscoder < Paperclip::Processor
     def make
       return File.open(@file.path) unless needs_convert?
diff --git a/lib/paperclip/image_extractor.rb b/lib/paperclip/image_extractor.rb
index aab675a06..17fe4326f 100644
--- a/lib/paperclip/image_extractor.rb
+++ b/lib/paperclip/image_extractor.rb
@@ -31,21 +31,17 @@ module Paperclip
     private
 
     def extract_image_from_file!
-      ::Av.logger = Paperclip.logger
-
-      cli = ::Av.cli
       dst = Tempfile.new([File.basename(@file.path, '.*'), '.png'])
       dst.binmode
 
-      cli.add_source(@file.path)
-      cli.add_destination(dst.path)
-      cli.add_output_param loglevel: 'fatal'
-
       begin
-        cli.run
-      rescue Cocaine::ExitStatusError, ::Av::CommandError
+        command = Terrapin::CommandLine.new('ffmpeg', '-i :source -loglevel :loglevel -y :destination', logger: Paperclip.logger)
+        command.run(source: @file.path, destination: dst.path, loglevel: 'fatal')
+      rescue Terrapin::ExitStatusError
         dst.close(true)
         return nil
+      rescue Terrapin::CommandNotFoundError
+        raise Paperclip::Errors::CommandNotFoundError, 'Could not run the `ffmpeg` command. Please install ffmpeg.'
       end
 
       dst
diff --git a/lib/paperclip/response_with_limit_adapter.rb b/lib/paperclip/response_with_limit_adapter.rb
index 17a2abd25..deb89717a 100644
--- a/lib/paperclip/response_with_limit_adapter.rb
+++ b/lib/paperclip/response_with_limit_adapter.rb
@@ -17,9 +17,9 @@ module Paperclip
 
     def cache_current_values
       @original_filename = filename_from_content_disposition.presence || filename_from_path.presence || 'data'
-      @size = @target.response.content_length
       @tempfile = copy_to_tempfile(@target)
       @content_type = ContentTypeDetector.new(@tempfile.path).detect
+      @size = File.size(@tempfile)
     end
 
     def copy_to_tempfile(source)
diff --git a/lib/paperclip/transcoder.rb b/lib/paperclip/transcoder.rb
new file mode 100644
index 000000000..e99704086
--- /dev/null
+++ b/lib/paperclip/transcoder.rb
@@ -0,0 +1,102 @@
+# frozen_string_literal: true
+
+module Paperclip
+  # This transcoder is only to be used for the MediaAttachment model
+  # to check when uploaded videos are actually gifv's
+  class Transcoder < Paperclip::Processor
+    def initialize(file, options = {}, attachment = nil)
+      super
+
+      @current_format      = File.extname(@file.path)
+      @basename            = File.basename(@file.path, @current_format)
+      @format              = options[:format]
+      @time                = options[:time] || 3
+      @passthrough_options = options[:passthrough_options]
+      @convert_options     = options[:convert_options].dup
+    end
+
+    def make
+      metadata = VideoMetadataExtractor.new(@file.path)
+
+      unless metadata.valid?
+        log("Unsupported file #{@file.path}")
+        return File.open(@file.path)
+      end
+
+      update_attachment_type(metadata)
+      update_options_from_metadata(metadata)
+
+      destination = Tempfile.new([@basename, @format ? ".#{@format}" : ''])
+      destination.binmode
+
+      @output_options = @convert_options[:output]&.dup || {}
+      @input_options  = @convert_options[:input]&.dup  || {}
+
+      case @format.to_s
+      when /jpg$/, /jpeg$/, /png$/, /gif$/
+        @input_options['ss'] = @time
+
+        @output_options['f']       = 'image2'
+        @output_options['vframes'] = 1
+      when 'mp4'
+        @output_options['acodec'] = 'aac'
+        @output_options['strict'] = 'experimental'
+      end
+
+      command_arguments, interpolations = prepare_command(destination)
+
+      begin
+        command = Terrapin::CommandLine.new('ffmpeg', command_arguments.join(' '), logger: Paperclip.logger)
+        command.run(interpolations)
+      rescue Terrapin::ExitStatusError => e
+        raise Paperclip::Error, "Error while transcoding #{@basename}: #{e}"
+      rescue Terrapin::CommandNotFoundError
+        raise Paperclip::Errors::CommandNotFoundError, 'Could not run the `ffmpeg` command. Please install ffmpeg.'
+      end
+
+      destination
+    end
+
+    private
+
+    def prepare_command(destination)
+      command_arguments  = ['-nostdin']
+      interpolations     = {}
+      interpolation_keys = 0
+
+      @input_options.each_pair do |key, value|
+        interpolation_key = interpolation_keys
+        command_arguments << "-#{key} :#{interpolation_key}"
+        interpolations[interpolation_key] = value
+        interpolation_keys += 1
+      end
+
+      command_arguments << '-i :source'
+      interpolations[:source] = @file.path
+
+      @output_options.each_pair do |key, value|
+        interpolation_key = interpolation_keys
+        command_arguments << "-#{key} :#{interpolation_key}"
+        interpolations[interpolation_key] = value
+        interpolation_keys += 1
+      end
+
+      command_arguments << '-y :destination'
+      interpolations[:destination] = destination.path
+
+      [command_arguments, interpolations]
+    end
+
+    def update_options_from_metadata(metadata)
+      return unless @passthrough_options && @passthrough_options[:video_codecs].include?(metadata.video_codec) && @passthrough_options[:audio_codecs].include?(metadata.audio_codec) && @passthrough_options[:colorspaces].include?(metadata.colorspace)
+
+      @format          = @passthrough_options[:options][:format] || @format
+      @time            = @passthrough_options[:options][:time]   || @time
+      @convert_options = @passthrough_options[:options][:convert_options].dup
+    end
+
+    def update_attachment_type(metadata)
+      @attachment.instance.type = MediaAttachment.types[:gifv] unless metadata.audio_codec
+    end
+  end
+end
diff --git a/lib/paperclip/transcoder_extensions.rb b/lib/paperclip/transcoder_extensions.rb
deleted file mode 100644
index c0b2447f3..000000000
--- a/lib/paperclip/transcoder_extensions.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-# frozen_string_literal: true
-
-module Paperclip
-  module TranscoderExtensions
-    # Prevent the transcoder from modifying our meta hash
-    def initialize(file, options = {}, attachment = nil)
-      meta_value = attachment&.instance_read(:meta)
-      super
-      attachment&.instance_write(:meta, meta_value)
-    end
-  end
-end
-
-Paperclip::Transcoder.prepend(Paperclip::TranscoderExtensions)
diff --git a/lib/paperclip/video_transcoder.rb b/lib/paperclip/video_transcoder.rb
deleted file mode 100644
index 4d9544231..000000000
--- a/lib/paperclip/video_transcoder.rb
+++ /dev/null
@@ -1,26 +0,0 @@
-# frozen_string_literal: true
-
-module Paperclip
-  # This transcoder is only to be used for the MediaAttachment model
-  # to check when uploaded videos are actually gifv's
-  class VideoTranscoder < Paperclip::Processor
-    def make
-      movie = FFMPEG::Movie.new(@file.path)
-
-      attachment.instance.type = MediaAttachment.types[:gifv] unless movie.audio_codec
-
-      Paperclip::Transcoder.make(file, actual_options(movie), attachment)
-    end
-
-    private
-
-    def actual_options(movie)
-      opts = options[:passthrough_options]
-      if opts && opts[:video_codecs].include?(movie.video_codec) && opts[:audio_codecs].include?(movie.audio_codec) && opts[:colorspaces].include?(movie.colorspace)
-        opts[:options]
-      else
-        options
-      end
-    end
-  end
-end
diff --git a/lib/tasks/mastodon.rake b/lib/tasks/mastodon.rake
index 2ad1e778b..c89c4726e 100644
--- a/lib/tasks/mastodon.rake
+++ b/lib/tasks/mastodon.rake
@@ -333,8 +333,12 @@ namespace :mastodon do
       prompt.say 'This configuration will be written to .env.production'
 
       if prompt.yes?('Save configuration?')
+        incompatible_syntax = false
+
         env_contents = env.each_pair.map do |key, value|
           if value.is_a?(String) && value =~ /[\s\#\\"]/
+            incompatible_syntax = true
+
             if value =~ /[']/
               value = value.to_s.gsub(/[\\"\$]/) { |x| "\\#{x}" }
               "#{key}=\"#{value}\""
@@ -346,12 +350,19 @@ namespace :mastodon do
           end
         end.join("\n")
 
-        File.write(Rails.root.join('.env.production'), "# Generated with mastodon:setup on #{Time.now.utc}\n\n" + env_contents + "\n")
+        generated_header = "# Generated with mastodon:setup on #{Time.now.utc}\n\n".dup
+
+        if incompatible_syntax
+          generated_header << "# Some variables in this file will be interpreted differently whether you are\n"
+          generated_header << "# using docker-compose or not.\n\n"
+        end
+
+        File.write(Rails.root.join('.env.production'), "#{generated_header}#{env_contents}\n")
 
         if using_docker
           prompt.ok 'Below is your configuration, save it to an .env.production file outside Docker:'
           prompt.say "\n"
-          prompt.say File.read(Rails.root.join('.env.production'))
+          prompt.say "#{generated_header}#{env.each_pair.map { |key, value| "#{key}=#{value}" }.join("\n")}"
           prompt.say "\n"
           prompt.ok 'It is also saved within this container so you can proceed with this wizard.'
         end
diff --git a/lib/tasks/tests.rake b/lib/tasks/tests.rake
new file mode 100644
index 000000000..0f38b50e3
--- /dev/null
+++ b/lib/tasks/tests.rake
@@ -0,0 +1,181 @@
+# frozen_string_literal: true
+
+namespace :tests do
+  namespace :migrations do
+    desc 'Populate the database with test data for 2.0.0'
+    task populate_v2: :environment do
+      admin_key   = OpenSSL::PKey::RSA.new(2048)
+      user_key    = OpenSSL::PKey::RSA.new(2048)
+      remote_key  = OpenSSL::PKey::RSA.new(2048)
+      remote_key2 = OpenSSL::PKey::RSA.new(2048)
+      remote_key3 = OpenSSL::PKey::RSA.new(2048)
+      admin_private_key    = ActiveRecord::Base.connection.quote(admin_key.to_pem)
+      admin_public_key     = ActiveRecord::Base.connection.quote(admin_key.public_key.to_pem)
+      user_private_key     = ActiveRecord::Base.connection.quote(user_key.to_pem)
+      user_public_key      = ActiveRecord::Base.connection.quote(user_key.public_key.to_pem)
+      remote_public_key    = ActiveRecord::Base.connection.quote(remote_key.public_key.to_pem)
+      remote_public_key2   = ActiveRecord::Base.connection.quote(remote_key2.public_key.to_pem)
+      remote_public_key_ap = ActiveRecord::Base.connection.quote(remote_key3.public_key.to_pem)
+      local_domain = ActiveRecord::Base.connection.quote(Rails.configuration.x.local_domain)
+
+      ActiveRecord::Base.connection.execute(<<~SQL)
+        -- accounts
+
+        INSERT INTO "accounts"
+          (id, username, domain, private_key, public_key, created_at, updated_at)
+        VALUES
+          (1, 'admin', NULL, #{admin_private_key}, #{admin_public_key}, now(), now()),
+          (2, 'user',  NULL, #{user_private_key},  #{user_public_key},  now(), now());
+
+        INSERT INTO "accounts"
+          (id, username, domain, private_key, public_key, created_at, updated_at, remote_url, salmon_url)
+        VALUES
+          (3, 'remote', 'remote.com', NULL, #{remote_public_key}, now(), now(),
+           'https://remote.com/@remote', 'https://remote.com/salmon/1'),
+          (4, 'Remote', 'remote.com', NULL, #{remote_public_key}, now(), now(),
+           'https://remote.com/@Remote', 'https://remote.com/salmon/1'),
+          (5, 'REMOTE', 'Remote.com', NULL, #{remote_public_key2}, now(), now(),
+           'https://remote.com/stale/@REMOTE', 'https://remote.com/stale/salmon/1');
+
+        INSERT INTO "accounts"
+          (id, username, domain, private_key, public_key, created_at, updated_at, protocol, inbox_url, outbox_url, followers_url)
+        VALUES
+          (6, 'bob', 'activitypub.com', NULL, #{remote_public_key_ap}, now(), now(),
+           1, 'https://activitypub.com/users/bob/inbox', 'https://activitypub.com/users/bob/outbox', 'https://activitypub.com/users/bob/followers');
+
+        INSERT INTO "accounts"
+          (id, username, domain, private_key, public_key, created_at, updated_at)
+        VALUES
+          (7, 'user', #{local_domain}, #{user_private_key}, #{user_public_key}, now(), now()),
+          (8, 'pt_user', NULL, #{user_private_key}, #{user_public_key}, now(), now());
+
+        -- users
+
+        INSERT INTO "users"
+          (id, account_id, email, created_at, updated_at, admin)
+        VALUES
+          (1, 1, 'admin@localhost', now(), now(), true),
+          (2, 2, 'user@localhost', now(), now(), false);
+
+        INSERT INTO "users"
+          (id, account_id, email, created_at, updated_at, admin, locale)
+        VALUES
+          (3, 7, 'ptuser@localhost', now(), now(), false, 'pt');
+
+        -- statuses
+
+        INSERT INTO "statuses"
+          (id, account_id, text, created_at, updated_at)
+        VALUES
+          (1, 1, 'test', now(), now()),
+          (2, 1, '@remote@remote.com hello', now(), now()),
+          (3, 1, '@Remote@remote.com hello', now(), now()),
+          (4, 1, '@REMOTE@remote.com hello', now(), now());
+
+        INSERT INTO "statuses"
+          (id, account_id, text, created_at, updated_at, uri, local)
+        VALUES
+          (5, 1, 'activitypub status', now(), now(), 'https://localhost/users/admin/statuses/4', true);
+
+        INSERT INTO "statuses"
+          (id, account_id, text, created_at, updated_at)
+        VALUES
+          (6, 3, 'test', now(), now());
+
+        INSERT INTO "statuses"
+          (id, account_id, text, created_at, updated_at, in_reply_to_id, in_reply_to_account_id)
+        VALUES
+          (7, 4, '@admin hello', now(), now(), 3, 1);
+
+        INSERT INTO "statuses"
+          (id, account_id, text, created_at, updated_at)
+        VALUES
+          (8, 5, 'test', now(), now());
+
+        INSERT INTO "statuses"
+          (id, account_id, reblog_of_id, created_at, updated_at)
+        VALUES
+          (9, 1, 2, now(), now());
+
+        -- mentions (from previous statuses)
+
+        INSERT INTO "mentions"
+          (status_id, account_id, created_at, updated_at)
+        VALUES
+          (2, 3, now(), now()),
+          (3, 4, now(), now()),
+          (4, 5, now(), now());
+
+        -- stream entries
+
+        INSERT INTO "stream_entries"
+          (activity_id, account_id, activity_type, created_at, updated_at)
+        VALUES
+          (1, 1, 'status', now(), now()),
+          (2, 1, 'status', now(), now()),
+          (3, 1, 'status', now(), now()),
+          (4, 1, 'status', now(), now()),
+          (5, 1, 'status', now(), now()),
+          (6, 3, 'status', now(), now()),
+          (7, 4, 'status', now(), now()),
+          (8, 5, 'status', now(), now()),
+          (9, 1, 'status', now(), now());
+
+
+        -- custom emoji
+
+        INSERT INTO "custom_emojis"
+          (shortcode, created_at, updated_at)
+        VALUES
+          ('test', now(), now()),
+          ('Test', now(), now()),
+          ('blobcat', now(), now());
+
+        INSERT INTO "custom_emojis"
+          (shortcode, domain, uri, created_at, updated_at)
+        VALUES
+          ('blobcat', 'remote.org', 'https://remote.org/emoji/blobcat', now(), now()),
+          ('blobcat', 'Remote.org', 'https://remote.org/emoji/blobcat', now(), now()),
+          ('Blobcat', 'remote.org', 'https://remote.org/emoji/Blobcat', now(), now());
+
+        -- favourites
+
+        INSERT INTO "favourites"
+          (account_id, status_id, created_at, updated_at)
+        VALUES
+          (1, 1, now(), now()),
+          (1, 7, now(), now()),
+          (4, 1, now(), now()),
+          (3, 1, now(), now()),
+          (5, 1, now(), now());
+
+        -- pinned statuses
+
+        INSERT INTO "status_pins"
+          (account_id, status_id, created_at, updated_at)
+        VALUES
+          (1, 1, now(), now()),
+          (3, 6, now(), now()),
+          (4, 7, now(), now());
+
+        -- follows
+
+        INSERT INTO "follows"
+          (account_id, target_account_id, created_at, updated_at)
+        VALUES
+          (1, 5, now(), now()),
+          (6, 2, now(), now()),
+          (5, 2, now(), now()),
+          (6, 1, now(), now());
+
+        -- follow requests
+
+        INSERT INTO "follow_requests"
+          (account_id, target_account_id, created_at, updated_at)
+        VALUES
+          (2, 5, now(), now()),
+          (5, 1, now(), now());
+      SQL
+    end
+  end
+end
diff --git a/lib/terrapin/multi_pipe_extensions.rb b/lib/terrapin/multi_pipe_extensions.rb
new file mode 100644
index 000000000..51d7de37c
--- /dev/null
+++ b/lib/terrapin/multi_pipe_extensions.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: false
+# Fix adapted from https://github.com/thoughtbot/terrapin/pull/5
+
+module Terrapin
+  module MultiPipeExtensions
+    def read
+      read_streams(@stdout_in, @stderr_in)
+    end
+
+    def close_read
+      begin
+        @stdout_in.close
+      rescue IOError
+        # Do nothing
+      end
+
+      begin
+        @stderr_in.close
+      rescue IOError
+        # Do nothing
+      end
+    end
+
+    def read_streams(output, error)
+      @stdout_output = ''
+      @stderr_output = ''
+
+      read_fds = [output, error]
+
+      until read_fds.empty?
+        to_read, = IO.select(read_fds)
+
+        if to_read.include?(output)
+          @stdout_output << read_stream(output)
+          read_fds.delete(output) if output.closed?
+        end
+
+        if to_read.include?(error)
+          @stderr_output << read_stream(error)
+          read_fds.delete(error) if error.closed?
+        end
+      end
+    end
+
+    def read_stream(io)
+      result = ''
+
+      begin
+        while (partial_result = io.read_nonblock(8192))
+          result << partial_result
+        end
+      rescue EOFError, Errno::EPIPE
+        io.close
+      rescue Errno::EINTR, Errno::EWOULDBLOCK, Errno::EAGAIN
+        # Do nothing
+      end
+
+      result
+    end
+  end
+end
+
+Terrapin::CommandLine::MultiPipe.prepend(Terrapin::MultiPipeExtensions)
diff --git a/spec/controllers/activitypub/followers_synchronizations_controller_spec.rb b/spec/controllers/activitypub/followers_synchronizations_controller_spec.rb
index 88f4554c2..ca89dc2ae 100644
--- a/spec/controllers/activitypub/followers_synchronizations_controller_spec.rb
+++ b/spec/controllers/activitypub/followers_synchronizations_controller_spec.rb
@@ -5,11 +5,13 @@ RSpec.describe ActivityPub::FollowersSynchronizationsController, type: :controll
   let!(:follower_1) { Fabricate(:account, domain: 'example.com', uri: 'https://example.com/users/a') }
   let!(:follower_2) { Fabricate(:account, domain: 'example.com', uri: 'https://example.com/users/b') }
   let!(:follower_3) { Fabricate(:account, domain: 'foo.com', uri: 'https://foo.com/users/a') }
+  let!(:follower_4) { Fabricate(:account, username: 'instance-actor', domain: 'example.com', uri: 'https://example.com') }
 
   before do
     follower_1.follow!(account)
     follower_2.follow!(account)
     follower_3.follow!(account)
+    follower_4.follow!(account)
   end
 
   before do
@@ -45,7 +47,7 @@ RSpec.describe ActivityPub::FollowersSynchronizationsController, type: :controll
 
       it 'returns orderedItems with followers from example.com' do
         expect(body[:orderedItems]).to be_an Array
-        expect(body[:orderedItems].sort).to eq [follower_1.uri, follower_2.uri]
+        expect(body[:orderedItems].sort).to eq [follower_4.uri, follower_1.uri, follower_2.uri]
       end
 
       it 'returns private Cache-Control header' do
diff --git a/spec/controllers/api/v1/accounts/notes_controller_spec.rb b/spec/controllers/api/v1/accounts/notes_controller_spec.rb
new file mode 100644
index 000000000..0a2957fed
--- /dev/null
+++ b/spec/controllers/api/v1/accounts/notes_controller_spec.rb
@@ -0,0 +1,48 @@
+require 'rails_helper'
+
+describe Api::V1::Accounts::NotesController do
+  render_views
+
+  let(:user)    { Fabricate(:user, account: Fabricate(:account, username: 'alice')) }
+  let(:token)   { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: 'write:accounts') }
+  let(:account) { Fabricate(:account) }
+  let(:comment) { 'foo' }
+
+  before do
+    allow(controller).to receive(:doorkeeper_token) { token }
+  end
+
+  describe 'POST #create' do
+    subject do
+      post :create, params: { account_id: account.id, comment: comment }
+    end
+
+    context 'when account note has reasonable length' do
+      let(:comment) { 'foo' }
+
+      it 'returns http success' do
+        subject
+        expect(response).to have_http_status(200)
+      end
+
+      it 'updates account note' do
+        subject
+        expect(AccountNote.find_by(account_id: user.account.id, target_account_id: account.id).comment).to eq comment
+      end
+    end
+
+    context 'when account note exceends allowed length' do
+      let(:comment) { 'a' * 2_001 }
+
+      it 'returns 422' do
+        subject
+        expect(response).to have_http_status(422)
+      end
+
+      it 'does not create account note' do
+        subject
+        expect(AccountNote.where(account_id: user.account.id, target_account_id: account.id).exists?).to be_falsey
+      end
+    end
+  end
+end
diff --git a/spec/controllers/api/v1/accounts_controller_spec.rb b/spec/controllers/api/v1/accounts_controller_spec.rb
index 1e656503f..d9ee37ffa 100644
--- a/spec/controllers/api/v1/accounts_controller_spec.rb
+++ b/spec/controllers/api/v1/accounts_controller_spec.rb
@@ -268,6 +268,34 @@ RSpec.describe Api::V1::AccountsController, type: :controller do
     it_behaves_like 'forbidden for wrong scope', 'read:accounts'
   end
 
+  describe 'POST #mute with nonzero duration set' do
+    let(:scopes) { 'write:mutes' }
+    let(:other_account) { Fabricate(:user, email: 'bob@example.com', account: Fabricate(:account, username: 'bob')).account }
+
+    before do
+      user.account.follow!(other_account)
+      post :mute, params: { id: other_account.id, duration: 300 }
+    end
+
+    it 'returns http success' do
+      expect(response).to have_http_status(200)
+    end
+
+    it 'does not remove the following relation between user and target user' do
+      expect(user.account.following?(other_account)).to be true
+    end
+
+    it 'creates a muting relation' do
+      expect(user.account.muting?(other_account)).to be true
+    end
+
+    it 'mutes notifications' do
+      expect(user.account.muting_notifications?(other_account)).to be true
+    end
+
+    it_behaves_like 'forbidden for wrong scope', 'read:accounts'
+  end
+
   describe 'POST #unmute' do
     let(:scopes) { 'write:mutes' }
     let(:other_account) { Fabricate(:user, email: 'bob@example.com', account: Fabricate(:account, username: 'bob')).account }
diff --git a/spec/controllers/api/v1/apps_controller_spec.rb b/spec/controllers/api/v1/apps_controller_spec.rb
index 60a4c3b41..70cd62d48 100644
--- a/spec/controllers/api/v1/apps_controller_spec.rb
+++ b/spec/controllers/api/v1/apps_controller_spec.rb
@@ -4,23 +4,83 @@ RSpec.describe Api::V1::AppsController, type: :controller do
   render_views
 
   describe 'POST #create' do
+    let(:client_name) { 'Test app' }
+    let(:scopes) { nil }
+    let(:redirect_uris) { 'urn:ietf:wg:oauth:2.0:oob' }
+    let(:website) { nil }
+
+    let(:app_params) do
+      {
+        client_name: client_name,
+        redirect_uris: redirect_uris,
+        scopes: scopes,
+        website: website,
+      }
+    end
+
     before do
-      post :create, params: { client_name: 'Test app', redirect_uris: 'urn:ietf:wg:oauth:2.0:oob' }
+      post :create, params: app_params
     end
 
-    it 'returns http success' do
-      expect(response).to have_http_status(200)
+    context 'with valid params' do
+      it 'returns http success' do
+        expect(response).to have_http_status(200)
+      end
+
+      it 'creates an OAuth app' do
+        expect(Doorkeeper::Application.find_by(name: client_name)).to_not be nil
+      end
+
+      it 'returns client ID and client secret' do
+        json = body_as_json
+
+        expect(json[:client_id]).to_not be_blank
+        expect(json[:client_secret]).to_not be_blank
+      end
     end
 
-    it 'creates an OAuth app' do
-      expect(Doorkeeper::Application.find_by(name: 'Test app')).to_not be nil
+    context 'with an unsupported scope' do
+      let(:scopes) { 'hoge' }
+
+      it 'returns http unprocessable entity' do
+        expect(response).to have_http_status(422)
+      end
     end
 
-    it 'returns client ID and client secret' do
-      json = body_as_json
+    context 'with many duplicate scopes' do
+      let(:scopes) { (%w(read) * 40).join(' ') }
 
-      expect(json[:client_id]).to_not be_blank
-      expect(json[:client_secret]).to_not be_blank
+      it 'returns http success' do
+        expect(response).to have_http_status(200)
+      end
+
+      it 'only saves the scope once' do
+        expect(Doorkeeper::Application.find_by(name: client_name).scopes.to_s).to eq 'read'
+      end
+    end
+
+    context 'with a too-long name' do
+      let(:client_name) { 'hoge' * 20 }
+
+      it 'returns http unprocessable entity' do
+        expect(response).to have_http_status(422)
+      end
+    end
+
+    context 'with a too-long website' do
+      let(:website) { 'https://foo.bar/' + ('hoge' * 2_000) }
+
+      it 'returns http unprocessable entity' do
+        expect(response).to have_http_status(422)
+      end
+    end
+
+    context 'with a too-long redirect_uris' do
+      let(:redirect_uris) { 'https://foo.bar/' + ('hoge' * 2_000) }
+
+      it 'returns http unprocessable entity' do
+        expect(response).to have_http_status(422)
+      end
     end
   end
 end
diff --git a/spec/controllers/auth/sessions_controller_spec.rb b/spec/controllers/auth/sessions_controller_spec.rb
index d3a9a11eb..608859f8c 100644
--- a/spec/controllers/auth/sessions_controller_spec.rb
+++ b/spec/controllers/auth/sessions_controller_spec.rb
@@ -206,6 +206,38 @@ RSpec.describe Auth::SessionsController, type: :controller do
           end
         end
 
+        context 'using email and password after an unfinished log-in attempt to a 2FA-protected account' do
+          let!(:other_user) do
+            Fabricate(:user, email: 'z@y.com', password: 'abcdefgh', otp_required_for_login: true, otp_secret: User.generate_otp_secret(32))
+          end
+
+          before do
+            post :create, params: { user: { email: other_user.email, password: other_user.password } }
+            post :create, params: { user: { email: user.email, password: user.password } }
+          end
+
+          it 'renders two factor authentication page' do
+            expect(controller).to render_template("two_factor")
+            expect(controller).to render_template(partial: "_otp_authentication_form")
+          end
+        end
+
+        context 'using email and password after an unfinished log-in attempt with a sign-in token challenge' do
+          let!(:other_user) do
+            Fabricate(:user, email: 'z@y.com', password: 'abcdefgh', otp_required_for_login: false, current_sign_in_at: 1.month.ago)
+          end
+
+          before do
+            post :create, params: { user: { email: other_user.email, password: other_user.password } }
+            post :create, params: { user: { email: user.email, password: user.password } }
+          end
+
+          it 'renders two factor authentication page' do
+            expect(controller).to render_template("two_factor")
+            expect(controller).to render_template(partial: "_otp_authentication_form")
+          end
+        end
+
         context 'using upcase email and password' do
           before do
             post :create, params: { user: { email: user.email.upcase, password: user.password } }
@@ -231,6 +263,21 @@ RSpec.describe Auth::SessionsController, type: :controller do
           end
         end
 
+        context 'using a valid OTP, attempting to leverage previous half-login to bypass password auth' do
+          let!(:other_user) do
+            Fabricate(:user, email: 'z@y.com', password: 'abcdefgh', otp_required_for_login: false, current_sign_in_at: 1.month.ago)
+          end
+
+          before do
+            post :create, params: { user: { email: other_user.email, password: other_user.password } }
+            post :create, params: { user: { email: user.email, otp_attempt: user.current_otp } }, session: { attempt_user_updated_at: user.updated_at.to_s }
+          end
+
+          it "doesn't log the user in" do
+            expect(controller.current_user).to be_nil
+          end
+        end
+
         context 'when the server has an decryption error' do
           before do
             allow_any_instance_of(User).to receive(:validate_and_consume_otp!).and_raise(OpenSSL::Cipher::CipherError)
@@ -380,6 +427,52 @@ RSpec.describe Auth::SessionsController, type: :controller do
         end
       end
 
+      context 'using email and password after an unfinished log-in attempt to a 2FA-protected account' do
+        let!(:other_user) do
+          Fabricate(:user, email: 'z@y.com', password: 'abcdefgh', otp_required_for_login: true, otp_secret: User.generate_otp_secret(32))
+        end
+
+        before do
+          post :create, params: { user: { email: other_user.email, password: other_user.password } }
+          post :create, params: { user: { email: user.email, password: user.password } }
+        end
+
+        it 'renders sign in token authentication page' do
+          expect(controller).to render_template("sign_in_token")
+        end
+
+        it 'generates sign in token' do
+          expect(user.reload.sign_in_token).to_not be_nil
+        end
+
+        it 'sends sign in token e-mail' do
+          expect(UserMailer).to have_received(:sign_in_token)
+        end
+      end
+
+      context 'using email and password after an unfinished log-in attempt with a sign-in token challenge' do
+        let!(:other_user) do
+          Fabricate(:user, email: 'z@y.com', password: 'abcdefgh', otp_required_for_login: false, current_sign_in_at: 1.month.ago)
+        end
+
+        before do
+          post :create, params: { user: { email: other_user.email, password: other_user.password } }
+          post :create, params: { user: { email: user.email, password: user.password } }
+        end
+
+        it 'renders sign in token authentication page' do
+          expect(controller).to render_template("sign_in_token")
+        end
+
+        it 'generates sign in token' do
+          expect(user.reload.sign_in_token).to_not be_nil
+        end
+
+        it 'sends sign in token e-mail' do
+          expect(UserMailer).to have_received(:sign_in_token).with(user, any_args)
+        end
+      end
+
       context 'using a valid sign in token' do
         before do
           user.generate_sign_in_token && user.save
@@ -395,6 +488,22 @@ RSpec.describe Auth::SessionsController, type: :controller do
         end
       end
 
+      context 'using a valid sign in token, attempting to leverage previous half-login to bypass password auth' do
+        let!(:other_user) do
+          Fabricate(:user, email: 'z@y.com', password: 'abcdefgh', otp_required_for_login: false, current_sign_in_at: 1.month.ago)
+        end
+
+        before do
+          user.generate_sign_in_token && user.save
+          post :create, params: { user: { email: other_user.email, password: other_user.password } }
+          post :create, params: { user: { email: user.email, sign_in_token_attempt: user.sign_in_token } }, session: { attempt_user_updated_at: user.updated_at.to_s }
+        end
+
+        it "doesn't log the user in" do
+          expect(controller.current_user).to be_nil
+        end
+      end
+
       context 'using an invalid sign in token' do
         before do
           post :create, params: { user: { sign_in_token_attempt: 'wrongotp' } }, session: { attempt_user_id: user.id, attempt_user_updated_at: user.updated_at.to_s }
@@ -410,4 +519,33 @@ RSpec.describe Auth::SessionsController, type: :controller do
       end
     end
   end
+
+  describe 'GET #webauthn_options' do
+    context 'with WebAuthn and OTP enabled as second factor' do
+      let(:domain) { "#{Rails.configuration.x.use_https ? 'https' : 'http' }://#{Rails.configuration.x.web_domain}" }
+
+      let(:fake_client) { WebAuthn::FakeClient.new(domain) }
+
+      let!(:user) do
+        Fabricate(:user, email: 'x@y.com', password: 'abcdefgh', otp_required_for_login: true, otp_secret: User.generate_otp_secret(32))
+      end
+
+      before do
+        user.update(webauthn_id: WebAuthn.generate_user_id)
+        public_key_credential = WebAuthn::Credential.from_create(fake_client.create)
+        user.webauthn_credentials.create(
+          nickname: 'SecurityKeyNickname',
+          external_id: public_key_credential.id,
+          public_key: public_key_credential.public_key,
+          sign_count: '1000'
+        )
+        post :create, params: { user: { email: user.email, password: user.password } }
+      end
+
+      it 'returns http success' do
+        get :webauthn_options
+        expect(response).to have_http_status :ok
+      end
+    end
+  end
 end
diff --git a/spec/controllers/follower_accounts_controller_spec.rb b/spec/controllers/follower_accounts_controller_spec.rb
index f6d55f693..006274169 100644
--- a/spec/controllers/follower_accounts_controller_spec.rb
+++ b/spec/controllers/follower_accounts_controller_spec.rb
@@ -3,7 +3,7 @@ require 'rails_helper'
 describe FollowerAccountsController do
   render_views
 
-  let(:alice) { Fabricate(:account, username: 'alice') }
+  let(:alice) { Fabricate(:user).account }
   let(:follower0) { Fabricate(:account) }
   let(:follower1) { Fabricate(:account) }
 
@@ -101,6 +101,23 @@ describe FollowerAccountsController do
           expect(body['partOf']).to be_blank
         end
 
+        context 'when account hides their network' do
+          before do
+            alice.user.settings.hide_network = true
+          end
+
+          it 'returns followers count' do
+            expect(body['totalItems']).to eq 2
+          end
+
+          it 'does not return items' do
+            expect(body['items']).to be_blank
+            expect(body['orderedItems']).to be_blank
+            expect(body['first']).to be_blank
+            expect(body['last']).to be_blank
+          end
+        end
+
         context 'when account is permanently suspended' do
           before do
             alice.suspend!
diff --git a/spec/controllers/following_accounts_controller_spec.rb b/spec/controllers/following_accounts_controller_spec.rb
index 0fc0967a6..7ec0e3d06 100644
--- a/spec/controllers/following_accounts_controller_spec.rb
+++ b/spec/controllers/following_accounts_controller_spec.rb
@@ -3,7 +3,7 @@ require 'rails_helper'
 describe FollowingAccountsController do
   render_views
 
-  let(:alice) { Fabricate(:account, username: 'alice') }
+  let(:alice) { Fabricate(:user).account }
   let(:followee0) { Fabricate(:account) }
   let(:followee1) { Fabricate(:account) }
 
@@ -101,6 +101,23 @@ describe FollowingAccountsController do
           expect(body['partOf']).to be_blank
         end
 
+        context 'when account hides their network' do
+          before do
+            alice.user.settings.hide_network = true
+          end
+
+          it 'returns followers count' do
+            expect(body['totalItems']).to eq 2
+          end
+
+          it 'does not return items' do
+            expect(body['items']).to be_blank
+            expect(body['orderedItems']).to be_blank
+            expect(body['first']).to be_blank
+            expect(body['last']).to be_blank
+          end
+        end
+
         context 'when account is permanently suspended' do
           before do
             alice.suspend!
diff --git a/spec/controllers/settings/migrations_controller_spec.rb b/spec/controllers/settings/migrations_controller_spec.rb
index 36e4ba86e..048d9de8d 100644
--- a/spec/controllers/settings/migrations_controller_spec.rb
+++ b/spec/controllers/settings/migrations_controller_spec.rb
@@ -51,7 +51,7 @@ describe Settings::MigrationsController do
       it_behaves_like 'authenticate user'
     end
 
-    context 'when user is sign in' do
+    context 'when user is signed in' do
       subject { post :create, params: { account_migration: { acct: acct, current_password: '12345678' } } }
 
       let(:user) { Fabricate(:user, password: '12345678') }
@@ -67,12 +67,45 @@ describe Settings::MigrationsController do
         end
       end
 
-      context 'when acct is a current account' do
+      context 'when acct is the current account' do
         let(:acct) { user.account }
 
         it 'renders show' do
           is_expected.to render_template :show
         end
+
+        it 'does not update the moved account' do
+          expect(user.account.reload.moved_to_account_id).to be_nil
+        end
+      end
+
+      context 'when target account does not reference the account being moved from' do
+        let(:acct) { Fabricate(:account, also_known_as: []) }
+
+        it 'renders show' do
+          is_expected.to render_template :show
+        end
+
+        it 'does not update the moved account' do
+          expect(user.account.reload.moved_to_account_id).to be_nil
+        end
+      end
+
+      context 'when a recent migration already exists ' do
+        let(:acct) { Fabricate(:account, also_known_as: [ActivityPub::TagManager.instance.uri_for(user.account)]) }
+
+        before do
+          moved_to = Fabricate(:account, also_known_as: [ActivityPub::TagManager.instance.uri_for(user.account)])
+          user.account.migrations.create!(acct: moved_to.acct)
+        end
+
+        it 'renders show' do
+          is_expected.to render_template :show
+        end
+
+        it 'does not update the moved account' do
+          expect(user.account.reload.moved_to_account_id).to be_nil
+        end
       end
     end
   end
diff --git a/spec/fixtures/requests/oembed_youtube.html b/spec/fixtures/requests/oembed_youtube.html
new file mode 100644
index 000000000..1508e4dd9
--- /dev/null
+++ b/spec/fixtures/requests/oembed_youtube.html
@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <link rel="alternate" type="application/json+oembed" href="https://www.youtube.com/oembed?format=json&amp;url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DIPSbNdBmWKE" title="What is Mastodon?">
+  </head>
+  <body></body>
+</html>
diff --git a/spec/lib/activitypub/activity/create_spec.rb b/spec/lib/activitypub/activity/create_spec.rb
index 632269055..415ee45d8 100644
--- a/spec/lib/activitypub/activity/create_spec.rb
+++ b/spec/lib/activitypub/activity/create_spec.rb
@@ -67,7 +67,7 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
-      context 'public' do
+      context 'public with explicit public address' do
         let(:object_json) do
           {
             id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
@@ -85,7 +85,43 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
-      context 'unlisted' do
+      context 'public with as:Public' do
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            to: 'as:Public',
+          }
+        end
+
+        it 'creates status' do
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.visibility).to eq 'public'
+        end
+      end
+
+      context 'public with Public' do
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            to: 'Public',
+          }
+        end
+
+        it 'creates status' do
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.visibility).to eq 'public'
+        end
+      end
+
+      context 'unlisted with explicit public address' do
         let(:object_json) do
           {
             id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
@@ -103,6 +139,42 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
+      context 'unlisted with as:Public' do
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            cc: 'as:Public',
+          }
+        end
+
+        it 'creates status' do
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.visibility).to eq 'unlisted'
+        end
+      end
+
+      context 'unlisted with Public' do
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            cc: 'Public',
+          }
+        end
+
+        it 'creates status' do
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.visibility).to eq 'unlisted'
+        end
+      end
+
       context 'private' do
         let(:object_json) do
           {
diff --git a/spec/lib/activitypub/activity/delete_spec.rb b/spec/lib/activitypub/activity/delete_spec.rb
index 37b93ecf7..9dfb8a61b 100644
--- a/spec/lib/activitypub/activity/delete_spec.rb
+++ b/spec/lib/activitypub/activity/delete_spec.rb
@@ -49,4 +49,24 @@ RSpec.describe ActivityPub::Activity::Delete do
       end
     end
   end
+
+  context 'when the status has been reported' do
+    describe '#perform' do
+      subject { described_class.new(json, sender) }
+      let!(:reporter) { Fabricate(:account) }
+
+      before do
+        reporter.reports.create!(target_account: status.account, status_ids: [status.id], forwarded: false)
+        subject.perform
+      end
+
+      it 'marks the status as deleted' do
+        expect(Status.find_by(id: status.id)).to be_nil
+      end
+
+      it 'actually keeps a copy for inspection' do
+        expect(Status.with_discarded.find_by(id: status.id)).to_not be_nil
+      end
+    end
+  end
 end
diff --git a/spec/lib/activitypub/activity/follow_spec.rb b/spec/lib/activitypub/activity/follow_spec.rb
index 05112cc18..fd4ede82b 100644
--- a/spec/lib/activitypub/activity/follow_spec.rb
+++ b/spec/lib/activitypub/activity/follow_spec.rb
@@ -17,62 +17,171 @@ RSpec.describe ActivityPub::Activity::Follow do
   describe '#perform' do
     subject { described_class.new(json, sender) }
 
-    context 'unlocked account' do
-      before do
-        subject.perform
+    context 'with no prior follow' do
+      context 'unlocked account' do
+        before do
+          subject.perform
+        end
+
+        it 'creates a follow from sender to recipient' do
+          expect(sender.following?(recipient)).to be true
+          expect(sender.active_relationships.find_by(target_account: recipient).uri).to eq 'foo'
+        end
+
+        it 'does not create a follow request' do
+          expect(sender.requested?(recipient)).to be false
+        end
       end
 
-      it 'creates a follow from sender to recipient' do
-        expect(sender.following?(recipient)).to be true
+      context 'silenced account following an unlocked account' do
+        before do
+          sender.touch(:silenced_at)
+          subject.perform
+        end
+
+        it 'does not create a follow from sender to recipient' do
+          expect(sender.following?(recipient)).to be false
+        end
+
+        it 'creates a follow request' do
+          expect(sender.requested?(recipient)).to be true
+          expect(sender.follow_requests.find_by(target_account: recipient).uri).to eq 'foo'
+        end
       end
 
-      it 'does not create a follow request' do
-        expect(sender.requested?(recipient)).to be false
+      context 'unlocked account muting the sender' do
+        before do
+          recipient.mute!(sender)
+          subject.perform
+        end
+
+        it 'creates a follow from sender to recipient' do
+          expect(sender.following?(recipient)).to be true
+          expect(sender.active_relationships.find_by(target_account: recipient).uri).to eq 'foo'
+        end
+
+        it 'does not create a follow request' do
+          expect(sender.requested?(recipient)).to be false
+        end
+      end
+
+      context 'locked account' do
+        before do
+          recipient.update(locked: true)
+          subject.perform
+        end
+
+        it 'does not create a follow from sender to recipient' do
+          expect(sender.following?(recipient)).to be false
+        end
+
+        it 'creates a follow request' do
+          expect(sender.requested?(recipient)).to be true
+          expect(sender.follow_requests.find_by(target_account: recipient).uri).to eq 'foo'
+        end
       end
     end
 
-    context 'silenced account following an unlocked account' do
+    context 'when a follow relationship already exists' do
       before do
-        sender.touch(:silenced_at)
-        subject.perform
+        sender.active_relationships.create!(target_account: recipient, uri: 'bar')
       end
 
-      it 'does not create a follow from sender to recipient' do
-        expect(sender.following?(recipient)).to be false
+      context 'unlocked account' do
+        before do
+          subject.perform
+        end
+
+        it 'correctly sets the new URI' do
+          expect(sender.active_relationships.find_by(target_account: recipient).uri).to eq 'foo'
+        end
+
+        it 'does not create a follow request' do
+          expect(sender.requested?(recipient)).to be false
+        end
       end
 
-      it 'creates a follow request' do
-        expect(sender.requested?(recipient)).to be true
+      context 'silenced account following an unlocked account' do
+        before do
+          sender.touch(:silenced_at)
+          subject.perform
+        end
+
+        it 'correctly sets the new URI' do
+          expect(sender.active_relationships.find_by(target_account: recipient).uri).to eq 'foo'
+        end
+
+        it 'does not create a follow request' do
+          expect(sender.requested?(recipient)).to be false
+        end
+      end
+
+      context 'unlocked account muting the sender' do
+        before do
+          recipient.mute!(sender)
+          subject.perform
+        end
+
+        it 'correctly sets the new URI' do
+          expect(sender.active_relationships.find_by(target_account: recipient).uri).to eq 'foo'
+        end
+
+        it 'does not create a follow request' do
+          expect(sender.requested?(recipient)).to be false
+        end
+      end
+
+      context 'locked account' do
+        before do
+          recipient.update(locked: true)
+          subject.perform
+        end
+
+        it 'correctly sets the new URI' do
+          expect(sender.active_relationships.find_by(target_account: recipient).uri).to eq 'foo'
+        end
+
+        it 'does not create a follow request' do
+          expect(sender.requested?(recipient)).to be false
+        end
       end
     end
 
-    context 'unlocked account muting the sender' do
+    context 'when a follow request already exists' do
       before do
-        recipient.mute!(sender)
-        subject.perform
+        sender.follow_requests.create!(target_account: recipient, uri: 'bar')
       end
 
-      it 'creates a follow from sender to recipient' do
-        expect(sender.following?(recipient)).to be true
+      context 'silenced account following an unlocked account' do
+        before do
+          sender.touch(:silenced_at)
+          subject.perform
+        end
+
+        it 'does not create a follow from sender to recipient' do
+          expect(sender.following?(recipient)).to be false
+        end
+
+        it 'correctly sets the new URI' do
+          expect(sender.requested?(recipient)).to be true
+          expect(sender.follow_requests.find_by(target_account: recipient).uri).to eq 'foo'
+        end
       end
 
-      it 'does not create a follow request' do
-        expect(sender.requested?(recipient)).to be false
-      end
-    end
+      context 'locked account' do
+        before do
+          recipient.update(locked: true)
+          subject.perform
+        end
 
-    context 'locked account' do
-      before do
-        recipient.update(locked: true)
-        subject.perform
-      end
+        it 'does not create a follow from sender to recipient' do
+          expect(sender.following?(recipient)).to be false
+        end
 
-      it 'does not create a follow from sender to recipient' do
-        expect(sender.following?(recipient)).to be false
-      end
-
-      it 'creates a follow request' do
-        expect(sender.requested?(recipient)).to be true
+        it 'correctly sets the new URI' do
+          expect(sender.requested?(recipient)).to be true
+          expect(sender.follow_requests.find_by(target_account: recipient).uri).to eq 'foo'
+        end
       end
     end
   end
diff --git a/spec/lib/activitypub/activity/move_spec.rb b/spec/lib/activitypub/activity/move_spec.rb
index 3574f273a..2d1d276c5 100644
--- a/spec/lib/activitypub/activity/move_spec.rb
+++ b/spec/lib/activitypub/activity/move_spec.rb
@@ -1,23 +1,11 @@
 require 'rails_helper'
 
 RSpec.describe ActivityPub::Activity::Move do
-  let(:follower)    { Fabricate(:account) }
-  let(:old_account) { Fabricate(:account) }
-  let(:new_account) { Fabricate(:account) }
-
-  before do
-    follower.follow!(old_account)
-
-    old_account.update!(uri: 'https://example.org/alice', domain: 'example.org', protocol: :activitypub, inbox_url: 'https://example.org/inbox')
-    new_account.update!(uri: 'https://example.com/alice', domain: 'example.com', protocol: :activitypub, inbox_url: 'https://example.com/inbox', also_known_as: [old_account.uri])
-
-    stub_request(:post, 'https://example.org/inbox').to_return(status: 200)
-    stub_request(:post, 'https://example.com/inbox').to_return(status: 200)
-
-    service_stub = double
-    allow(ActivityPub::FetchRemoteAccountService).to receive(:new).and_return(service_stub)
-    allow(service_stub).to receive(:call).and_return(new_account)
-  end
+  let(:follower)         { Fabricate(:account) }
+  let(:old_account)      { Fabricate(:account, uri: 'https://example.org/alice', domain: 'example.org', protocol: :activitypub, inbox_url: 'https://example.org/inbox') }
+  let(:new_account)      { Fabricate(:account, uri: 'https://example.com/alice', domain: 'example.com', protocol: :activitypub, inbox_url: 'https://example.com/inbox', also_known_as: also_known_as) }
+  let(:also_known_as)    { [old_account.uri] }
+  let(:returned_account) { new_account }
 
   let(:json) do
     {
@@ -30,6 +18,17 @@ RSpec.describe ActivityPub::Activity::Move do
     }.with_indifferent_access
   end
 
+  before do
+    follower.follow!(old_account)
+
+    stub_request(:post, old_account.inbox_url).to_return(status: 200)
+    stub_request(:post, new_account.inbox_url).to_return(status: 200)
+
+    service_stub = double
+    allow(ActivityPub::FetchRemoteAccountService).to receive(:new).and_return(service_stub)
+    allow(service_stub).to receive(:call).and_return(returned_account)
+  end
+
   describe '#perform' do
     subject { described_class.new(json, old_account) }
 
@@ -37,16 +36,70 @@ RSpec.describe ActivityPub::Activity::Move do
       subject.perform
     end
 
-    it 'sets moved account on old account' do
-      expect(old_account.reload.moved_to_account_id).to eq new_account.id
+    context 'when all conditions are met' do
+      it 'sets moved account on old account' do
+        expect(old_account.reload.moved_to_account_id).to eq new_account.id
+      end
+
+      it 'makes followers unfollow old account' do
+        expect(follower.following?(old_account)).to be false
+      end
+
+      it 'makes followers follow-request the new account' do
+        expect(follower.requested?(new_account)).to be true
+      end
     end
 
-    it 'makes followers unfollow old account' do
-      expect(follower.following?(old_account)).to be false
+    context "when the new account can't be resolved" do
+      let(:returned_account) { nil }
+
+      it 'does not set moved account on old account' do
+        expect(old_account.reload.moved_to_account_id).to be_nil
+      end
+
+      it 'does not make followers unfollow old account' do
+        expect(follower.following?(old_account)).to be true
+      end
+
+      it 'does not make followers follow-request the new account' do
+        expect(follower.requested?(new_account)).to be false
+      end
     end
 
-    it 'makes followers follow-request the new account' do
-      expect(follower.requested?(new_account)).to be true
+    context 'when the new account does not references the old account' do
+      let(:also_known_as) { [] }
+
+      it 'does not set moved account on old account' do
+        expect(old_account.reload.moved_to_account_id).to be_nil
+      end
+
+      it 'does not make followers unfollow old account' do
+        expect(follower.following?(old_account)).to be true
+      end
+
+      it 'does not make followers follow-request the new account' do
+        expect(follower.requested?(new_account)).to be false
+      end
+    end
+
+    context 'when a Move has been recently processed' do
+      around do |example|
+        Redis.current.set("move_in_progress:#{old_account.id}", true, nx: true, ex: 7.days.seconds)
+        example.run
+        Redis.current.del("move_in_progress:#{old_account.id}")
+      end
+
+      it 'does not set moved account on old account' do
+        expect(old_account.reload.moved_to_account_id).to be_nil
+      end
+
+      it 'does not make followers unfollow old account' do
+        expect(follower.following?(old_account)).to be true
+      end
+
+      it 'does not make followers follow-request the new account' do
+        expect(follower.requested?(new_account)).to be false
+      end
     end
   end
 end
diff --git a/spec/lib/activitypub/tag_manager_spec.rb b/spec/lib/activitypub/tag_manager_spec.rb
index 1c5c6f0ed..606a1de2e 100644
--- a/spec/lib/activitypub/tag_manager_spec.rb
+++ b/spec/lib/activitypub/tag_manager_spec.rb
@@ -42,6 +42,14 @@ RSpec.describe ActivityPub::TagManager do
       expect(subject.to(status)).to eq [subject.uri_for(mentioned)]
     end
 
+    it "returns URIs of mentioned group's followers for direct statuses to groups" do
+      status    = Fabricate(:status, visibility: :direct)
+      mentioned = Fabricate(:account, domain: 'remote.org', uri: 'https://remote.org/group', followers_url: 'https://remote.org/group/followers', actor_type: 'Group')
+      status.mentions.create(account: mentioned)
+      expect(subject.to(status)).to include(subject.uri_for(mentioned))
+      expect(subject.to(status)).to include(subject.followers_uri_for(mentioned))
+    end
+
     it "returns URIs of mentions for direct silenced author's status only if they are followers or requesting to be" do
       bob    = Fabricate(:account, username: 'bob')
       alice  = Fabricate(:account, username: 'alice')
diff --git a/spec/models/concerns/account_interactions_spec.rb b/spec/models/concerns/account_interactions_spec.rb
index 85fbf7e79..ca243ebc5 100644
--- a/spec/models/concerns/account_interactions_spec.rb
+++ b/spec/models/concerns/account_interactions_spec.rb
@@ -539,46 +539,57 @@ describe AccountInteractions do
     end
   end
 
-  describe '#followers_hash' do
+  describe '#remote_followers_hash' do
     let(:me) { Fabricate(:account, username: 'Me') }
     let(:remote_1) { Fabricate(:account, username: 'alice', domain: 'example.org', uri: 'https://example.org/users/alice') }
     let(:remote_2) { Fabricate(:account, username: 'bob', domain: 'example.org', uri: 'https://example.org/users/bob') }
-    let(:remote_3) { Fabricate(:account, username: 'eve', domain: 'foo.org', uri: 'https://foo.org/users/eve') }
+    let(:remote_3) { Fabricate(:account, username: 'instance-actor', domain: 'example.org', uri: 'https://example.org') }
+    let(:remote_4) { Fabricate(:account, username: 'eve', domain: 'foo.org', uri: 'https://foo.org/users/eve') }
 
     before do
       remote_1.follow!(me)
       remote_2.follow!(me)
       remote_3.follow!(me)
+      remote_4.follow!(me)
       me.follow!(remote_1)
     end
 
-    context 'on a local user' do
-      it 'returns correct hash for remote domains' do
-        expect(me.remote_followers_hash('https://example.org/')).to eq '707962e297b7bd94468a21bc8e506a1bcea607a9142cd64e27c9b106b2a5f6ec'
-        expect(me.remote_followers_hash('https://foo.org/')).to eq 'ccb9c18a67134cfff9d62c7f7e7eb88e6b803446c244b84265565f4eba29df0e'
-      end
-
-      it 'invalidates cache as needed when removing or adding followers' do
-        expect(me.remote_followers_hash('https://example.org/')).to eq '707962e297b7bd94468a21bc8e506a1bcea607a9142cd64e27c9b106b2a5f6ec'
-        remote_1.unfollow!(me)
-        expect(me.remote_followers_hash('https://example.org/')).to eq '241b00794ce9b46aa864f3220afadef128318da2659782985bac5ed5bd436bff'
-        remote_1.follow!(me)
-        expect(me.remote_followers_hash('https://example.org/')).to eq '707962e297b7bd94468a21bc8e506a1bcea607a9142cd64e27c9b106b2a5f6ec'
-      end
+    it 'returns correct hash for remote domains' do
+      expect(me.remote_followers_hash('https://example.org/')).to eq '20aecbe774b3d61c25094370baf370012b9271c5b172ecedb05caff8d79ef0c7'
+      expect(me.remote_followers_hash('https://foo.org/')).to eq 'ccb9c18a67134cfff9d62c7f7e7eb88e6b803446c244b84265565f4eba29df0e'
+      expect(me.remote_followers_hash('https://foo.org.evil.com/')).to eq '0000000000000000000000000000000000000000000000000000000000000000'
+      expect(me.remote_followers_hash('https://foo')).to eq '0000000000000000000000000000000000000000000000000000000000000000'
     end
 
-    context 'on a remote user' do
-      it 'returns correct hash for remote domains' do
-        expect(remote_1.local_followers_hash).to eq Digest::SHA256.hexdigest(ActivityPub::TagManager.instance.uri_for(me))
-      end
+    it 'invalidates cache as needed when removing or adding followers' do
+      expect(me.remote_followers_hash('https://example.org/')).to eq '20aecbe774b3d61c25094370baf370012b9271c5b172ecedb05caff8d79ef0c7'
+      remote_3.unfollow!(me)
+      expect(me.remote_followers_hash('https://example.org/')).to eq '707962e297b7bd94468a21bc8e506a1bcea607a9142cd64e27c9b106b2a5f6ec'
+      remote_1.unfollow!(me)
+      expect(me.remote_followers_hash('https://example.org/')).to eq '241b00794ce9b46aa864f3220afadef128318da2659782985bac5ed5bd436bff'
+      remote_1.follow!(me)
+      expect(me.remote_followers_hash('https://example.org/')).to eq '707962e297b7bd94468a21bc8e506a1bcea607a9142cd64e27c9b106b2a5f6ec'
+    end
+  end
 
-      it 'invalidates cache as needed when removing or adding followers' do
-        expect(remote_1.local_followers_hash).to eq Digest::SHA256.hexdigest(ActivityPub::TagManager.instance.uri_for(me))
-        me.unfollow!(remote_1)
-        expect(remote_1.local_followers_hash).to eq '0000000000000000000000000000000000000000000000000000000000000000'
-        me.follow!(remote_1)
-        expect(remote_1.local_followers_hash).to eq Digest::SHA256.hexdigest(ActivityPub::TagManager.instance.uri_for(me))
-      end
+  describe '#local_followers_hash' do
+    let(:me) { Fabricate(:account, username: 'Me') }
+    let(:remote_1) { Fabricate(:account, username: 'alice', domain: 'example.org', uri: 'https://example.org/users/alice') }
+
+    before do
+      me.follow!(remote_1)
+    end
+
+    it 'returns correct hash for local users' do
+      expect(remote_1.local_followers_hash).to eq Digest::SHA256.hexdigest(ActivityPub::TagManager.instance.uri_for(me))
+    end
+
+    it 'invalidates cache as needed when removing or adding followers' do
+      expect(remote_1.local_followers_hash).to eq Digest::SHA256.hexdigest(ActivityPub::TagManager.instance.uri_for(me))
+      me.unfollow!(remote_1)
+      expect(remote_1.local_followers_hash).to eq '0000000000000000000000000000000000000000000000000000000000000000'
+      me.follow!(remote_1)
+      expect(remote_1.local_followers_hash).to eq Digest::SHA256.hexdigest(ActivityPub::TagManager.instance.uri_for(me))
     end
   end
 
diff --git a/spec/models/follow_request_spec.rb b/spec/models/follow_request_spec.rb
index cc484a5b9..36ce8ee60 100644
--- a/spec/models/follow_request_spec.rb
+++ b/spec/models/follow_request_spec.rb
@@ -7,7 +7,7 @@ RSpec.describe FollowRequest, type: :model do
     let(:target_account) { Fabricate(:account) }
 
     it 'calls Account#follow!, MergeWorker.perform_async, and #destroy!' do
-      expect(account).to        receive(:follow!).with(target_account, reblogs: true, notify: false, uri: follow_request.uri)
+      expect(account).to        receive(:follow!).with(target_account, reblogs: true, notify: false, uri: follow_request.uri, bypass_limit: true)
       expect(MergeWorker).to    receive(:perform_async).with(target_account.id, account.id)
       expect(follow_request).to receive(:destroy!)
       follow_request.authorize!
diff --git a/spec/services/activitypub/process_account_service_spec.rb b/spec/services/activitypub/process_account_service_spec.rb
index 56e7f8321..1b1d878a7 100644
--- a/spec/services/activitypub/process_account_service_spec.rb
+++ b/spec/services/activitypub/process_account_service_spec.rb
@@ -12,6 +12,7 @@ RSpec.describe ActivityPub::ProcessAccountService, type: :service do
         attachment: [
           { type: 'PropertyValue', name: 'Pronouns', value: 'They/them' },
           { type: 'PropertyValue', name: 'Occupation', value: 'Unit test' },
+          { type: 'PropertyValue', name: 'non-string', value: ['foo', 'bar'] },
         ],
       }.with_indifferent_access
     end
diff --git a/spec/services/after_block_service_spec.rb b/spec/services/after_block_service_spec.rb
index f63b2045a..fe5b26b2b 100644
--- a/spec/services/after_block_service_spec.rb
+++ b/spec/services/after_block_service_spec.rb
@@ -5,12 +5,14 @@ RSpec.describe AfterBlockService, type: :service do
     -> { described_class.new.call(account, target_account) }
   end
 
-  let(:account) { Fabricate(:account) }
-  let(:target_account) { Fabricate(:account) }
+  let(:account)              { Fabricate(:account) }
+  let(:target_account)       { Fabricate(:account) }
+  let(:status)               { Fabricate(:status, account: target_account) }
+  let(:other_status)         { Fabricate(:status, account: target_account) }
+  let(:other_account_status) { Fabricate(:status) }
+  let(:other_account_reblog) { Fabricate(:status, reblog_of_id: other_status.id) }
 
   describe 'home timeline' do
-    let(:status) { Fabricate(:status, account: target_account) }
-    let(:other_account_status) { Fabricate(:status) }
     let(:home_timeline_key) { FeedManager.instance.key(:home, account.id) }
 
     before do
@@ -20,10 +22,30 @@ RSpec.describe AfterBlockService, type: :service do
     it "clears account's statuses" do
       FeedManager.instance.push_to_home(account, status)
       FeedManager.instance.push_to_home(account, other_account_status)
+      FeedManager.instance.push_to_home(account, other_account_reblog)
 
       is_expected.to change {
         Redis.current.zrange(home_timeline_key, 0, -1)
-      }.from([status.id.to_s, other_account_status.id.to_s]).to([other_account_status.id.to_s])
+      }.from([status.id.to_s, other_account_status.id.to_s, other_account_reblog.id.to_s]).to([other_account_status.id.to_s])
+    end
+  end
+
+  describe 'lists' do
+    let(:list)              { Fabricate(:list, account: account) }
+    let(:list_timeline_key) { FeedManager.instance.key(:list, list.id) }
+
+    before do
+      Redis.current.del(list_timeline_key)
+    end
+
+    it "clears account's statuses" do
+      FeedManager.instance.push_to_list(list, status)
+      FeedManager.instance.push_to_list(list, other_account_status)
+      FeedManager.instance.push_to_list(list, other_account_reblog)
+
+      is_expected.to change {
+        Redis.current.zrange(list_timeline_key, 0, -1)
+      }.from([status.id.to_s, other_account_status.id.to_s, other_account_reblog.id.to_s]).to([other_account_status.id.to_s])
     end
   end
 end
diff --git a/spec/services/fetch_oembed_service_spec.rb b/spec/services/fetch_oembed_service_spec.rb
index a4262b040..88f0113ed 100644
--- a/spec/services/fetch_oembed_service_spec.rb
+++ b/spec/services/fetch_oembed_service_spec.rb
@@ -13,6 +13,32 @@ describe FetchOEmbedService, type: :service do
 
   describe 'discover_provider' do
     context 'when status code is 200 and MIME type is text/html' do
+      context 'when OEmbed endpoint contains URL as parameter' do
+        before do
+          stub_request(:get, 'https://www.youtube.com/watch?v=IPSbNdBmWKE').to_return(
+            status: 200,
+            headers: { 'Content-Type': 'text/html' },
+            body: request_fixture('oembed_youtube.html'),
+          )
+          stub_request(:get, 'https://www.youtube.com/oembed?format=json&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DIPSbNdBmWKE').to_return(
+            status: 200,
+            headers: { 'Content-Type': 'text/html' },
+            body: request_fixture('oembed_json_empty.html')
+          )
+        end
+
+        it 'returns new OEmbed::Provider for JSON provider' do
+          subject.call('https://www.youtube.com/watch?v=IPSbNdBmWKE')
+          expect(subject.endpoint_url).to eq 'https://www.youtube.com/oembed?format=json&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DIPSbNdBmWKE'
+          expect(subject.format).to eq :json
+        end
+
+        it 'stores URL template' do
+          subject.call('https://www.youtube.com/watch?v=IPSbNdBmWKE')
+          expect(Rails.cache.read('oembed_endpoint:www.youtube.com')[:endpoint]).to eq 'https://www.youtube.com/oembed?format=json&url={url}'
+        end
+      end
+
       context 'Both of JSON and XML provider are discoverable' do
         before do
           stub_request(:get, 'https://host.test/oembed.html').to_return(
@@ -33,6 +59,11 @@ describe FetchOEmbedService, type: :service do
           expect(subject.endpoint_url).to eq 'https://host.test/provider.xml'
           expect(subject.format).to eq :xml
         end
+
+        it 'does not cache OEmbed endpoint' do
+          subject.call('https://host.test/oembed.html', format: :xml)
+          expect(Rails.cache.exist?('oembed_endpoint:host.test')).to eq false
+        end
       end
 
       context 'JSON provider is discoverable while XML provider is not' do
@@ -49,6 +80,11 @@ describe FetchOEmbedService, type: :service do
           expect(subject.endpoint_url).to eq 'https://host.test/provider.json'
           expect(subject.format).to eq :json
         end
+
+        it 'does not cache OEmbed endpoint' do
+          subject.call('https://host.test/oembed.html')
+          expect(Rails.cache.exist?('oembed_endpoint:host.test')).to eq false
+        end
       end
 
       context 'XML provider is discoverable while JSON provider is not' do
@@ -65,6 +101,11 @@ describe FetchOEmbedService, type: :service do
           expect(subject.endpoint_url).to eq 'https://host.test/provider.xml'
           expect(subject.format).to eq :xml
         end
+
+        it 'does not cache OEmbed endpoint' do
+          subject.call('https://host.test/oembed.html')
+          expect(Rails.cache.exist?('oembed_endpoint:host.test')).to eq false
+        end
       end
 
       context 'Invalid XML provider is discoverable while JSON provider is not' do
diff --git a/spec/services/notify_service_spec.rb b/spec/services/notify_service_spec.rb
index f2cb22c5e..7433866b7 100644
--- a/spec/services/notify_service_spec.rb
+++ b/spec/services/notify_service_spec.rb
@@ -64,8 +64,9 @@ RSpec.describe NotifyService, type: :service do
         is_expected.to_not change(Notification, :count)
       end
 
-      context 'if the message chain initiated by recipient, but is not direct message' do
+      context 'if the message chain is initiated by recipient, but is not direct message' do
         let(:reply_to) { Fabricate(:status, account: recipient) }
+        let!(:mention) { Fabricate(:mention, account: sender, status: reply_to) }
         let(:activity) { Fabricate(:mention, account: recipient, status: Fabricate(:status, account: sender, visibility: :direct, thread: reply_to)) }
 
         it 'does not notify' do
@@ -73,8 +74,20 @@ RSpec.describe NotifyService, type: :service do
         end
       end
 
-      context 'if the message chain initiated by recipient and is direct message' do
+      context 'if the message chain is initiated by recipient, but without a mention to the sender, even if the sender sends multiple messages in a row' do
+        let(:reply_to) { Fabricate(:status, account: recipient) }
+        let!(:mention) { Fabricate(:mention, account: sender, status: reply_to) }
+        let(:dummy_reply) { Fabricate(:status, account: sender, visibility: :direct, thread: reply_to) }
+        let(:activity) { Fabricate(:mention, account: recipient, status: Fabricate(:status, account: sender, visibility: :direct, thread: dummy_reply)) }
+
+        it 'does not notify' do
+          is_expected.to_not change(Notification, :count)
+        end
+      end
+
+      context 'if the message chain is initiated by the recipient with a mention to the sender' do
         let(:reply_to) { Fabricate(:status, account: recipient, visibility: :direct) }
+        let!(:mention) { Fabricate(:mention, account: sender, status: reply_to) }
         let(:activity) { Fabricate(:mention, account: recipient, status: Fabricate(:status, account: sender, visibility: :direct, thread: reply_to)) }
 
         it 'does notify' do
diff --git a/spec/services/post_status_service_spec.rb b/spec/services/post_status_service_spec.rb
index 147a59fc3..d21270c79 100644
--- a/spec/services/post_status_service_spec.rb
+++ b/spec/services/post_status_service_spec.rb
@@ -25,29 +25,33 @@ RSpec.describe PostStatusService, type: :service do
     expect(status.thread).to eq in_reply_to_status
   end
 
-  it 'schedules a status' do
-    account = Fabricate(:account)
-    future  = Time.now.utc + 2.hours
+  context 'when scheduling a status' do
+    let!(:account)         { Fabricate(:account) }
+    let!(:future)          { Time.now.utc + 2.hours }
+    let!(:previous_status) { Fabricate(:status, account: account) }
 
-    status = subject.call(account, text: 'Hi future!', scheduled_at: future)
+    it 'schedules a status' do
+      status = subject.call(account, text: 'Hi future!', scheduled_at: future)
+      expect(status).to be_a ScheduledStatus
+      expect(status.scheduled_at).to eq future
+      expect(status.params['text']).to eq 'Hi future!'
+    end
 
-    expect(status).to be_a ScheduledStatus
-    expect(status.scheduled_at).to eq future
-    expect(status.params['text']).to eq 'Hi future!'
-  end
+    it 'does not immediately create a status' do
+      media = Fabricate(:media_attachment, account: account)
+      status = subject.call(account, text: 'Hi future!', media_ids: [media.id], scheduled_at: future)
 
-  it 'does not immediately create a status when scheduling a status' do
-    account = Fabricate(:account)
-    media = Fabricate(:media_attachment)
-    future  = Time.now.utc + 2.hours
+      expect(status).to be_a ScheduledStatus
+      expect(status.scheduled_at).to eq future
+      expect(status.params['text']).to eq 'Hi future!'
+      expect(status.params['media_ids']).to eq [media.id]
+      expect(media.reload.status).to be_nil
+      expect(Status.where(text: 'Hi future!').exists?).to be_falsey
+    end
 
-    status = subject.call(account, text: 'Hi future!', media_ids: [media.id], scheduled_at: future)
-
-    expect(status).to be_a ScheduledStatus
-    expect(status.scheduled_at).to eq future
-    expect(status.params['text']).to eq 'Hi future!'
-    expect(media.reload.status).to be_nil
-    expect(Status.where(text: 'Hi future!').exists?).to be_falsey
+    it 'does not change statuses count' do
+      expect { subject.call(account, text: 'Hi future!', scheduled_at: future, thread: previous_status) }.not_to change { [account.statuses_count, previous_status.replies_count] }
+    end
   end
 
   it 'creates response to the original status of boost' do
diff --git a/spec/services/process_mentions_service_spec.rb b/spec/services/process_mentions_service_spec.rb
index c30de8eeb..69f8310c2 100644
--- a/spec/services/process_mentions_service_spec.rb
+++ b/spec/services/process_mentions_service_spec.rb
@@ -73,6 +73,24 @@ RSpec.describe ProcessMentionsService, type: :service do
         expect(a_request(:post, remote_user.inbox_url)).to have_been_made.once
       end
     end
+
+    context 'with an IDN TLD' do
+      let(:remote_user) { Fabricate(:account, username: 'foo', protocol: :activitypub, domain: 'xn--y9a3aq.xn--y9a3aq', inbox_url: 'http://example.com/inbox') }
+      let(:status) { Fabricate(:status, account: account, text: "Hello @foo@հայ.հայ") }
+
+      before do
+        stub_request(:post, remote_user.inbox_url)
+        subject.call(status)
+      end
+
+      it 'creates a mention' do
+        expect(remote_user.mentions.where(status: status).count).to eq 1
+      end
+
+      it 'sends activity to the inbox' do
+        expect(a_request(:post, remote_user.inbox_url)).to have_been_made.once
+      end
+    end
   end
 
   context 'Temporarily-unreachable ActivityPub user' do
diff --git a/spec/workers/activitypub/delivery_worker_spec.rb b/spec/workers/activitypub/delivery_worker_spec.rb
index f4633731e..d39393d50 100644
--- a/spec/workers/activitypub/delivery_worker_spec.rb
+++ b/spec/workers/activitypub/delivery_worker_spec.rb
@@ -11,7 +11,7 @@ describe ActivityPub::DeliveryWorker do
   let(:payload) { 'test' }
 
   before do
-    allow_any_instance_of(Account).to receive(:remote_followers_hash).with('https://example.com/').and_return('somehash')
+    allow_any_instance_of(Account).to receive(:remote_followers_hash).with('https://example.com/api').and_return('somehash')
   end
 
   describe 'perform' do
diff --git a/spec/workers/move_worker_spec.rb b/spec/workers/move_worker_spec.rb
index 8ab4f182f..82449b0c7 100644
--- a/spec/workers/move_worker_spec.rb
+++ b/spec/workers/move_worker_spec.rb
@@ -9,7 +9,8 @@ describe MoveWorker do
   let(:source_account)   { Fabricate(:account, protocol: :activitypub, domain: 'example.com') }
   let(:target_account)   { Fabricate(:account, protocol: :activitypub, domain: 'example.com') }
   let(:local_user)       { Fabricate(:user) }
-  let!(:account_note)    { Fabricate(:account_note, account: local_user.account, target_account: source_account) }
+  let(:comment)          { 'old note prior to move' }
+  let!(:account_note)    { Fabricate(:account_note, account: local_user.account, target_account: source_account, comment: comment) }
 
   let(:block_service) { double }
 
@@ -26,19 +27,37 @@ describe MoveWorker do
   end
 
   shared_examples 'user note handling' do
-    it 'copies user note' do
-      subject.perform(source_account.id, target_account.id)
-      expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(source_account.acct)
-      expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
+    context 'when user notes are short enough' do
+      it 'copies user note with prelude' do
+        subject.perform(source_account.id, target_account.id)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(source_account.acct)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
+      end
+
+      it 'merges user notes when needed' do
+        new_account_note = AccountNote.create!(account: account_note.account, target_account: target_account, comment: 'new note prior to move')
+
+        subject.perform(source_account.id, target_account.id)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(source_account.acct)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(new_account_note.comment)
+      end
     end
 
-    it 'merges user notes when needed' do
-      new_account_note = AccountNote.create!(account: account_note.account, target_account: target_account, comment: 'new note prior to move')
+    context 'when user notes are too long' do
+      let(:comment) { 'abc' * 333 }
 
-      subject.perform(source_account.id, target_account.id)
-      expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(source_account.acct)
-      expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
-      expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(new_account_note.comment)
+      it 'copies user note without prelude' do
+        subject.perform(source_account.id, target_account.id)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
+      end
+
+      it 'keeps user notes unchanged' do
+        new_account_note = AccountNote.create!(account: account_note.account, target_account: target_account, comment: 'new note prior to move')
+
+        subject.perform(source_account.id, target_account.id)
+        expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(new_account_note.comment)
+      end
     end
   end