9 files changed, 65 insertions, 8 deletions
diff --git a/app/lib/activitypub/activity.rb b/app/lib/activitypub/activity.rb
index 0a729011f..87318fb1c 100644
--- a/app/lib/activitypub/activity.rb
+++ b/app/lib/activitypub/activity.rb
@@ -50,6 +50,8 @@ class ActivityPub::Activity
         ActivityPub::Activity::Add
       when 'Remove'
         ActivityPub::Activity::Remove
+      when 'Move'
+        ActivityPub::Activity::Move
       end
     end
   end
diff --git a/app/lib/activitypub/activity/block.rb b/app/lib/activitypub/activity/block.rb
index 26da8bdf5..a17a2d50a 100644
--- a/app/lib/activitypub/activity/block.rb
+++ b/app/lib/activitypub/activity/block.rb
@@ -4,9 +4,10 @@ class ActivityPub::Activity::Block < 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.blocking?(target_account)
+    return if target_account.nil? || !target_account.local? || @account.blocking?(target_account)
 
     UnfollowService.new.call(target_account, @account) if target_account.following?(@account)
-    @account.block!(target_account, uri: @json['id'])
+
+    @account.block!(target_account, uri: @json['id']) unless delete_arrived_first?(@json['id'])
   end
 end
diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 9d2ddd3f6..2b238bc88 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -210,7 +210,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   end
 
   def resolve_thread(status)
-    return unless status.reply? && status.thread.nil?
+    return unless status.reply? && status.thread.nil? && Request.valid_url?(in_reply_to_uri)
     ThreadResolveWorker.perform_async(status.id, in_reply_to_uri)
   end
 
diff --git a/app/lib/activitypub/activity/flag.rb b/app/lib/activitypub/activity/flag.rb
index 92e59bb81..0d10d6c3c 100644
--- a/app/lib/activitypub/activity/flag.rb
+++ b/app/lib/activitypub/activity/flag.rb
@@ -8,8 +8,6 @@ class ActivityPub::Activity::Flag < ActivityPub::Activity
     target_statuses_by_account = object_uris.map { |uri| status_from_uri(uri) }.compact.select(&:local?).group_by(&:account_id)
 
     target_accounts.each do |target_account|
-      next if Report.where(account: @account, target_account: target_account).exists?
-
       target_statuses = target_statuses_by_account[target_account.id]
 
       ReportService.new.call(
diff --git a/app/lib/activitypub/activity/follow.rb b/app/lib/activitypub/activity/follow.rb
index c45832648..1e805c0d1 100644
--- a/app/lib/activitypub/activity/follow.rb
+++ b/app/lib/activitypub/activity/follow.rb
@@ -6,7 +6,7 @@ class ActivityPub::Activity::Follow < ActivityPub::Activity
 
     return if target_account.nil? || !target_account.local? || delete_arrived_first?(@json['id']) || @account.requested?(target_account)
 
-    if target_account.blocking?(@account) || target_account.domain_blocking?(@account.domain)
+    if target_account.blocking?(@account) || target_account.domain_blocking?(@account.domain) || target_account.moved?
       reject_follow_request!(target_account)
       return
     end
@@ -28,7 +28,7 @@ class ActivityPub::Activity::Follow < ActivityPub::Activity
   end
 
   def reject_follow_request!(target_account)
-    json = Oj.dump(ActivityPub::LinkedDataSignature.new(ActiveModelSerializers::SerializableResource.new(FollowRequest.new(account: @account, target_account: target_account, uri: @json['id']), serializer: ActivityPub::RejectFollowSerializer, adapter: ActivityPub::Adapter).as_json).sign!(target_account))
+    json = ActiveModelSerializers::SerializableResource.new(FollowRequest.new(account: @account, target_account: target_account, uri: @json['id']), serializer: ActivityPub::RejectFollowSerializer, adapter: ActivityPub::Adapter).to_json
     ActivityPub::DeliveryWorker.perform_async(json, target_account.id, @account.inbox_url)
   end
 end
diff --git a/app/lib/activitypub/activity/move.rb b/app/lib/activitypub/activity/move.rb
new file mode 100644
index 000000000..d7a5f595c
--- /dev/null
+++ b/app/lib/activitypub/activity/move.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::Move < ActivityPub::Activity
+  PROCESSING_COOLDOWN = 7.days.seconds
+
+  def perform
+    return if origin_account.uri != object_uri || processed?
+
+    mark_as_processing!
+
+    target_account = ActivityPub::FetchRemoteAccountService.new.call(target_uri)
+
+    return if target_account.nil? || !target_account.also_known_as.include?(origin_account.uri)
+
+    # In case for some reason we didn't have a redirect for the profile already, set it
+    origin_account.update(moved_to_account: target_account) if origin_account.moved_to_account_id.nil?
+
+    # Initiate a re-follow for each follower
+    origin_account.followers.local.select(:id).find_in_batches do |follower_accounts|
+      UnfollowFollowWorker.push_bulk(follower_accounts.map(&:id)) do |follower_account_id|
+        [follower_account_id, origin_account.id, target_account.id]
+      end
+    end
+  end
+
+  private
+
+  def origin_account
+    @account
+  end
+
+  def target_uri
+    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)
+  end
+end
diff --git a/app/lib/activitypub/adapter.rb b/app/lib/activitypub/adapter.rb
index d35cae889..99f4d9305 100644
--- a/app/lib/activitypub/adapter.rb
+++ b/app/lib/activitypub/adapter.rb
@@ -10,6 +10,7 @@ class ActivityPub::Adapter < ActiveModelSerializers::Adapter::Base
         'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
         'sensitive'                 => 'as:sensitive',
         'movedTo'                   => { '@id' => 'as:movedTo', '@type' => '@id' },
+        'alsoKnownAs'               => { '@id' => 'as:alsoKnownAs', '@type' => '@id' },
         'Hashtag'                   => 'as:Hashtag',
         'ostatus'                   => 'http://ostatus.org#',
         'atomUri'                   => 'ostatus:atomUri',
diff --git a/app/lib/ostatus/activity/creation.rb b/app/lib/ostatus/activity/creation.rb
index 8f8c70052..3840c8fbf 100644
--- a/app/lib/ostatus/activity/creation.rb
+++ b/app/lib/ostatus/activity/creation.rb
@@ -57,7 +57,7 @@ class OStatus::Activity::Creation < OStatus::Activity::Base
       save_emojis(status)
     end
 
-    if thread? && status.thread.nil?
+    if thread? && status.thread.nil? && Request.valid_url?(thread.second)
       Rails.logger.debug "Trying to attach #{status.id} (#{id}) to #{thread.first}"
       ThreadResolveWorker.perform_async(status.id, thread.second)
     end
diff --git a/app/lib/request.rb b/app/lib/request.rb
index 4a81773e3..ef4aeaf29 100644
--- a/app/lib/request.rb
+++ b/app/lib/request.rb
@@ -66,6 +66,18 @@ class Request
     (@account ? @headers.merge('Signature' => signature) : @headers).without(REQUEST_TARGET)
   end
 
+  class << self
+    def valid_url?(url)
+      begin
+        parsed_url = Addressable::URI.parse(url)
+      rescue Addressable::URI::InvalidURIError
+        return false
+      end
+
+      %w(http https).include?(parsed_url.scheme) && parsed_url.host.present?
+    end
+  end
+
   private
 
   def set_common_headers!