Disallow making private posts quotable (#35780)

app/models/concerns/status/interaction_policy_concern.rb

@@ -10,6 +10,10 @@ module Status::InteractionPolicyConcern
     followed: (1 << 3),
   }.freeze
 
+  included do
+    before_validation :downgrade_quote_policy, if: -> { local? && !distributable? }
+  end
+
   def quote_policy_as_keys(kind)
     case kind
     when :automatic
@@ -52,4 +56,8 @@ module Status::InteractionPolicyConcern
 
     :denied
   end
+
+  def downgrade_quote_policy
+    self.quote_approval_policy = 0
+  end
 end

spec/requests/api/v1/statuses/interaction_policies_spec.rb

@@ -90,5 +90,31 @@ RSpec.describe 'Interaction policies', feature: :outgoing_quotes do
           .to_not have_enqueued_sidekiq_job
       end
     end
+
+    context 'when trying to change the interaction policy of a private post' do
+      let(:status) { Fabricate(:status, account: user.account, visibility: :private) }
+      let(:params) { { quote_approval_policy: 'public' } }
+
+      it 'keeps the interaction policy, returns the status, and does not schedule distribution jobs' do
+        expect { subject }
+          .to_not(change { status.reload.quote_approval_policy }.from(0))
+
+        expect(response).to have_http_status(200)
+        expect(response.content_type)
+          .to start_with('application/json')
+        expect(response.parsed_body).to include(
+          'quote_approval' => match(
+            'automatic' => [],
+            'manual' => [],
+            'current_user' => 'automatic'
+          )
+        )
+
+        expect(DistributionWorker)
+          .to_not have_enqueued_sidekiq_job
+        expect(ActivityPub::StatusUpdateDistributionWorker)
+          .to_not have_enqueued_sidekiq_job
+      end
+    end
   end
 end