Fix HTTP 200 response code on paths to remote accounts that don't exist (#40341)

app/controllers/concerns/web_app_controller_concern.rb

@@ -27,10 +27,7 @@ module WebAppControllerConcern
   end
 
   def redirect_unauthenticated_to_permalinks!
-    return if user_signed_in? && current_account.moved_to_account_id.nil?
-
-    permalink_redirector = PermalinkRedirector.new(request.original_fullpath)
-    return if permalink_redirector.redirect_path.blank?
+    return if (user_signed_in? && current_account.moved_to_account_id.nil?) || permalink_redirector.redirect_path.blank?
 
     expires_in(15.seconds, public: true, stale_while_revalidate: 30.seconds, stale_if_error: 1.day) unless user_signed_in?
 
@@ -72,4 +69,8 @@ module WebAppControllerConcern
   def set_referer_header
     response.set_header('Referrer-Policy', Setting.allow_referrer_origin ? 'strict-origin-when-cross-origin' : 'same-origin')
   end
+
+  def permalink_redirector
+    @permalink_redirector ||= PermalinkRedirector.new(request.original_fullpath)
+  end
 end

app/controllers/remote_accounts_controller.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+class RemoteAccountsController < HomeController
+  before_action :require_resource_exists!
+
+  private
+
+  def require_resource_exists!
+    # The page should still render normally, but the HTTP code should be modified
+    response.status = 404 if permalink_redirector.object.nil?
+  end
+end

app/services/resolve_url_service.rb

@@ -103,7 +103,7 @@ class ResolveURLService < BaseService
       return unless recognized_params[:action] == 'show'
 
       Account.find_local(recognized_params[:username])
-    when 'home'
+    when 'home', 'remote_accounts'
       return unless recognized_params[:action] == 'index' && recognized_params[:username_with_domain].present?
 
       if recognized_params[:any]&.match?(/\A[0-9]+\Z/)

config/routes.rb

@@ -176,7 +176,7 @@ Rails.application.routes.draw do
     get '/@:account_username/wrapstodon/:year/:share_key', to: 'wrapstodon#show', as: :public_wrapstodon
   end
 
-  get '/@:username_with_domain/(*any)', to: 'home#index', constraints: { username_with_domain: %r{([^/])+?} }, as: :account_with_domain, format: false
+  get '/@:username_with_domain/(*any)', to: 'remote_accounts#index', constraints: { username_with_domain: %r{([^/])+?} }, as: :account_with_domain, format: false
   get '/settings', to: redirect('/settings/profile')
 
   draw(:settings)

spec/routing/accounts_routing_spec.rb

@@ -107,35 +107,35 @@ RSpec.describe 'Routes under accounts/' do
     let(:username) { 'alice@example.com' }
 
     it 'routes /@:username' do
-      expect(get("/@#{username}")).to route_to('home#index', username_with_domain: username)
+      expect(get("/@#{username}")).to route_to('remote_accounts#index', username_with_domain: username)
     end
 
     it 'routes /@:username/:id' do
-      expect(get("/@#{username}/123")).to route_to('home#index', username_with_domain: username, any: '123')
+      expect(get("/@#{username}/123")).to route_to('remote_accounts#index', username_with_domain: username, any: '123')
     end
 
     it 'routes /@:username/:id/embed' do
-      expect(get("/@#{username}/123/embed")).to route_to('home#index', username_with_domain: username, any: '123/embed')
+      expect(get("/@#{username}/123/embed")).to route_to('remote_accounts#index', username_with_domain: username, any: '123/embed')
     end
 
     it 'routes /@:username/following' do
-      expect(get("/@#{username}/following")).to route_to('home#index', username_with_domain: username, any: 'following')
+      expect(get("/@#{username}/following")).to route_to('remote_accounts#index', username_with_domain: username, any: 'following')
     end
 
     it 'routes /@:username/followers' do
-      expect(get("/@#{username}/followers")).to route_to('home#index', username_with_domain: username, any: 'followers')
+      expect(get("/@#{username}/followers")).to route_to('remote_accounts#index', username_with_domain: username, any: 'followers')
     end
 
     it 'routes /@:username/with_replies' do
-      expect(get("/@#{username}/with_replies")).to route_to('home#index', username_with_domain: username, any: 'with_replies')
+      expect(get("/@#{username}/with_replies")).to route_to('remote_accounts#index', username_with_domain: username, any: 'with_replies')
     end
 
     it 'routes /@:username/media' do
-      expect(get("/@#{username}/media")).to route_to('home#index', username_with_domain: username, any: 'media')
+      expect(get("/@#{username}/media")).to route_to('remote_accounts#index', username_with_domain: username, any: 'media')
     end
 
     it 'routes /@:username/tagged/:tag' do
-      expect(get("/@#{username}/tagged/foo")).to route_to('home#index', username_with_domain: username, any: 'tagged/foo')
+      expect(get("/@#{username}/tagged/foo")).to route_to('remote_accounts#index', username_with_domain: username, any: 'tagged/foo')
     end
   end