Merge pull request #28897 from rafaelfranca/fix-name-error-error-page

Do not try to encoding the parameters when the controller is not defined

actionpack/lib/action_dispatch/http/parameters.rb

@@ -85,7 +85,7 @@ module ActionDispatch
 
         def set_binary_encoding(params)
           action = params[:action]
-          if controller_class.binary_params_for?(action)
+          if binary_params_for?(action)
             ActionDispatch::Request::Utils.each_param_value(params) do |param|
               param.force_encoding ::Encoding::ASCII_8BIT
             end
@@ -93,6 +93,12 @@ module ActionDispatch
           params
         end
 
+        def binary_params_for?(action)
+          controller_class.binary_params_for?(action)
+        rescue NameError
+          false
+        end
+
         def parse_formatted_parameters(parsers)
           return yield if content_length.zero? || content_mime_type.nil?
 

railties/test/application/middleware/exceptions_test.rb

@@ -100,6 +100,20 @@ module ApplicationTests
       end
     end
 
+    test "routing to an nonexistent controller when action_dispatch.show_exceptions and consider_all_requests_local are set shows diagnostics" do
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          resources :articles
+        end
+      RUBY
+
+      app.config.action_dispatch.show_exceptions = true
+      app.config.consider_all_requests_local = true
+
+      get "/articles"
+      assert_match "<title>Action Controller: Exception caught</title>", last_response.body
+    end
+
     test "displays diagnostics message when exception raised in template that contains UTF-8" do
       controller :foo, <<-RUBY
         class FooController < ActionController::Base