After blocking domain with reject_media, invalidate cache (#6679)

Media attachments are part of the association cache of statuses,
since they are presumed to be immutable. Unless this cache is
cleared manually, the statuses will continue to look like they
have media embedded.

app/services/block_domain_service.rb

@@ -5,13 +5,14 @@ class BlockDomainService < BaseService
 
   def call(domain_block)
     @domain_block = domain_block
-    process_domain_block
+    process_domain_block!
   end
 
   private
 
-  def process_domain_block
+  def process_domain_block!
     clear_media! if domain_block.reject_media?
+
     if domain_block.silence?
       silence_accounts!
     elsif domain_block.suspend?
@@ -19,14 +20,26 @@ class BlockDomainService < BaseService
     end
   end
 
+  def invalidate_association_caches!
+    # Normally, associated models of a status are immutable (except for accounts)
+    # so they are aggressively cached. After updating the media attachments to no
+    # longer point to a local file, we need to clear the cache to make those
+    # changes appear in the API and UI
+    @affected_status_ids.each { |id| Rails.cache.delete_matched("statuses/#{id}-*") }
+  end
+
   def silence_accounts!
     blocked_domain_accounts.in_batches.update_all(silenced: true)
   end
 
   def clear_media!
-    clear_account_images
-    clear_account_attachments
-    clear_emojos
+    @affected_status_ids = []
+
+    clear_account_images!
+    clear_account_attachments!
+    clear_emojos!
+
+    invalidate_association_caches!
   end
 
   def suspend_accounts!
@@ -36,23 +49,25 @@ class BlockDomainService < BaseService
     end
   end
 
-  def clear_account_images
+  def clear_account_images!
     blocked_domain_accounts.find_each do |account|
-      account.avatar.destroy
-      account.header.destroy
+      account.avatar.destroy if account.avatar.exists?
+      account.header.destroy if account.header.exists?
       account.save
     end
   end
 
-  def clear_account_attachments
+  def clear_account_attachments!
     media_from_blocked_domain.find_each do |attachment|
-      attachment.file.destroy
+      @affected_status_ids << attachment.status_id if attachment.status_id.present?
+
+      attachment.file.destroy if attachment.file.exists?
       attachment.type = :unknown
       attachment.save
     end
   end
 
-  def clear_emojos
+  def clear_emojos!
     emojis_from_blocked_domains.destroy_all
   end
 

lib/tasks/mastodon.rake

@@ -476,12 +476,12 @@ namespace :mastodon do
       time_ago = ENV.fetch('NUM_DAYS') { 7 }.to_i.days.ago
 
       MediaAttachment.where.not(remote_url: '').where.not(file_file_name: nil).where('created_at < ?', time_ago).find_each do |media|
-        if media.file.exists?
+        next unless media.file.exists?
+
         media.file.destroy
         media.save
       end
     end
-    end
 
     desc 'Set unknown attachment type for remote-only attachments'
     task set_unknown: :environment do