Resolves false-positive UnsafeRedirectError (#19297)

app/controllers/application_controller.rb

@@ -165,8 +165,12 @@ class ApplicationController < ActionController::Base
     end
   end
 
-  def redirect_permanently_to(location)
-    redirect_to location + internal_nav_param, status: :moved_permanently
+  def redirect_permanently_to(url = nil, **args)
+    if url
+      redirect_to(url + internal_nav_param, status: :moved_permanently)
+    else
+      redirect_to(args.merge({ i: params[:i] }), status: :moved_permanently)
+    end
   end
 
   def customize_params

app/controllers/stories_controller.rb

@@ -324,7 +324,7 @@ class StoriesController < ApplicationController
   def redirect_to_lowercase_username
     return unless params[:username]&.match?(/[[:upper:]]/)
 
-    redirect_permanently_to("/#{params[:username].downcase}")
+    redirect_permanently_to(action: :index, username: params[:username].downcase)
   end
 
   def set_user_json_ld

spec/requests/stories_index_spec.rb

@@ -1,16 +1,16 @@
 require "rails_helper"
 
-RSpec.shared_examples "redirects to the lowercase route" do
-  context "when a path contains uppercase characters" do
-    it "redirects to the lowercase route" do
-      get path
-      expect(response).to have_http_status(:moved_permanently)
-      expect(response).to redirect_to(path.downcase)
-    end
-  end
-end
-
 RSpec.describe "StoriesIndex" do
+  it "redirects to the lowercase route", :aggregate_failures do
+    get "/Bad_name"
+    expect(response).to have_http_status(:moved_permanently)
+    expect(response).to redirect_to("/bad_name")
+
+    get "/Bad_name?i=i"
+    expect(response).to have_http_status(:moved_permanently)
+    expect(response).to redirect_to("/bad_name?i=i")
+  end
+
   describe "GET stories index" do
     let(:user) { create(:user) }
 
@@ -346,10 +346,6 @@ RSpec.describe "StoriesIndex" do
   end
 
   describe "GET podcast index" do
-    include_examples "redirects to the lowercase route" do
-      let(:path) { "/#{build(:podcast).slug.upcase}" }
-    end
-
     it "renders page with proper header" do
       podcast = create(:podcast)
       create(:podcast_episode, podcast: podcast)
@@ -357,16 +353,4 @@ RSpec.describe "StoriesIndex" do
       expect(response.body).to include(podcast.title)
     end
   end
-
-  describe "GET user_path" do
-    include_examples "redirects to the lowercase route" do
-      let(:path) { "/#{build(:user).username.upcase}" }
-    end
-  end
-
-  describe "GET organization_path" do
-    include_examples "redirects to the lowercase route" do
-      let(:path) { "/#{build(:organization).slug.upcase}" }
-    end
-  end
 end