Explicitly record Tombstone quotes as deleted

This adds a `deleted` state to the internal representation, but this does
not change the API, which already included such a state.

app/lib/activitypub/activity/create.rb

@@ -220,8 +220,8 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     return unless @status_parser.quote?
 
     approval_uri = @status_parser.quote_approval_uri
-    approval_uri = nil if unsupported_uri_scheme?(approval_uri)
-    @quote = Quote.new(account: @account, approval_uri: approval_uri, legacy: @status_parser.legacy_quote?)
+    approval_uri = nil if unsupported_uri_scheme?(approval_uri) || TagManager.instance.local_url?(approval_uri)
+    @quote = Quote.new(account: @account, approval_uri: approval_uri, legacy: @status_parser.legacy_quote?, state: @status_parser.deleted_quote? ? :deleted : :pending)
   end
 
   def process_hashtag(tag)

app/lib/activitypub/parser/status_parser.rb

@@ -121,6 +121,10 @@ class ActivityPub::Parser::StatusParser
     %w(quote _misskey_quote quoteUrl quoteUri).any? { |key| @object[key].present? }
   end
 
+  def deleted_quote?
+    @object['quote'].is_a?(Hash) && @object['quote']['type'] == 'Tombstone'
+  end
+
   def quote_uri
     %w(quote _misskey_quote quoteUrl quoteUri).filter_map do |key|
       value_or_id(as_array(@object[key]).first)

app/models/quote.rb

@@ -21,7 +21,7 @@ class Quote < ApplicationRecord
   REFRESH_DEADLINE = 6.hours
 
   enum :state,
-       { pending: 0, accepted: 1, rejected: 2, revoked: 3 },
+       { pending: 0, accepted: 1, rejected: 2, revoked: 3, deleted: 4 },
        validate: true
 
   belongs_to :status

app/services/activitypub/process_status_update_service.rb

@@ -305,10 +305,12 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
       approval_uri = nil if unsupported_uri_scheme?(approval_uri)
 
       if @status.quote.present?
+        state = @status_parser.deleted_quote? ? :deleted : :pending
+
         # If the quoted post has changed, discard the old object and create a new one
         if @status.quote.quoted_status.present? && ActivityPub::TagManager.instance.uri_for(@status.quote.quoted_status) != quote_uri
           @status.quote.destroy
-          quote = Quote.create(status: @status, approval_uri: approval_uri, legacy: @status_parser.legacy_quote?)
+          quote = Quote.create(status: @status, approval_uri: approval_uri, legacy: @status_parser.legacy_quote?, state: state)
           @quote_changed = true
         else
           quote = @status.quote

spec/lib/activitypub/activity/create_spec.rb

@@ -956,7 +956,7 @@ RSpec.describe ActivityPub::Activity::Create do
           expect(status).to_not be_nil
           expect(status.quote).to_not be_nil
           expect(status.quote).to have_attributes(
-            state: 'pending',
+            state: 'deleted',
             approval_uri: nil
           )
         end

spec/services/activitypub/process_status_update_service_spec.rb

@@ -1008,7 +1008,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
     it 'updates the URI and unverifies the quote' do
       expect { subject.call(status, json, json) }
         .to change { status.quote.quoted_status }.from(quoted_status).to(nil)
-        .and change { status.quote.state }.from('accepted')
+        .and change { status.quote.state }.from('accepted').to('deleted')
 
       expect { quote.reload }.to raise_error(ActiveRecord::RecordNotFound)
     end