Match the controller and path names defensively.

Use '\A' instead of '^', and make the alteration shorter.

actionpack/lib/action_dispatch/routing/inspector.rb

@@ -51,7 +51,7 @@ def action
       end
 
       def internal?
-        controller =~ %r{^rails/info|^rails/welcome} || path =~ %r{^#{Rails.application.config.assets.prefix}}
+        controller =~ %r{\Arails/(info|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}}
       end
 
       def engine?