FIX: add 'noindex' header to rss feed responses.

app/controllers/application_controller.rb

@@ -44,6 +44,7 @@ class ApplicationController < ActionController::Base
   after_action  :perform_refresh_session
   after_action  :dont_cache_page
   after_action  :conditionally_allow_site_embedding
+  after_action  :add_noindex_header, if: -> { is_feed_request? }
 
   layout :set_layout
 
@@ -801,6 +802,14 @@ class ApplicationController < ActionController::Base
     request.env['DISCOURSE_IS_ASSET_PATH'] = 1
   end
 
+  def is_feed_request?
+    request.format.atom? || request.format.rss?
+  end
+
+  def add_noindex_header
+    response.headers['X-Robots-Tag'] = 'noindex'
+  end
+
   protected
 
   def render_post_json(post, add_raw: true)

app/controllers/users_controller.rb

@@ -47,6 +47,8 @@ class UsersController < ApplicationController
                                                             :admin_login,
                                                             :confirm_admin]
 
+  after_action :add_noindex_header, only: [:show]
+
   def index
   end
 
@@ -73,8 +75,6 @@ class UsersController < ApplicationController
       track_visit_to_user_profile
     end
 
-    response.headers['X-Robots-Tag'] = 'noindex'
-
     # This is a hack to get around a Rails issue where values with periods aren't handled correctly
     # when used as part of a route.
     if params[:external_id] && params[:external_id].ends_with?('.json')

spec/requests/list_controller_spec.rb

@@ -300,6 +300,7 @@ RSpec.describe ListController do
       get "/latest.rss"
       expect(response.status).to eq(200)
       expect(response.media_type).to eq('application/rss+xml')
+      expect(response.headers['X-Robots-Tag']).to eq('noindex')
     end
 
     it 'renders links correctly with subfolder' do