Make PuSH only distribute to subscriptions that match follower domains

Allow PuSH to distribute private toots with that condition

app/models/account.rb

@@ -95,6 +95,10 @@ class Account < ApplicationRecord
     follow_requests.where(target_account: other_account).exists?
   end
 
+  def followers_domains
+    followers.reorder('').select('DISTINCT accounts.domain').map(&:domain)
+  end
+
   def local?
     domain.nil?
   end

app/workers/pubsubhubbub/distribution_worker.rb

@@ -8,13 +8,18 @@ class Pubsubhubbub::DistributionWorker
   def perform(stream_entry_id)
     stream_entry = StreamEntry.find(stream_entry_id)
 
-    return if stream_entry.hidden?
+    # Most hidden stream entries should not be PuSHed,
+    # but statuses need to be distributed to trusted
+    # followers even when they are hidden
+    return if stream_entry.hidden? && stream_entry.activity_type != 'Status'
 
     account  = stream_entry.account
     renderer = AccountsController.renderer.new(method: 'get', http_host: Rails.configuration.x.local_domain, https: Rails.configuration.x.use_https)
     payload  = renderer.render(:show, assigns: { account: account, entries: [stream_entry] }, formats: [:atom])
+    domains  = account.followers_domains
 
-    Subscription.where(account: account).active.select('id').find_each do |subscription|
+    Subscription.where(account: account).active.select('id, callback_url').find_each do |subscription|
+      next unless domains.include?(Addressable::URI.parse(subscription.callback_url).host)
       Pubsubhubbub::DeliveryWorker.perform_async(subscription.id, payload)
     end
   rescue ActiveRecord::RecordNotFound