Just check request instead of controller.request

actionpack/lib/action_view/helpers/asset_url_helper.rb

@@ -136,7 +136,7 @@ def asset_path(source, options = {})
         end
 
         relative_url_root = (defined?(config.relative_url_root) && config.relative_url_root) ||
-          (asset_request && asset_request.script_name)
+          (respond_to?(:request) && request.try(:script_name))
         if relative_url_root
           source = "#{relative_url_root}#{source}" unless source.starts_with?("#{relative_url_root}/")
         end
@@ -181,7 +181,7 @@ def compute_asset_path(source, options = {})
       # or the value returned from invoking call on an object responding to call
       # (proc or otherwise).
       def compute_asset_host(source = "", options = {})
-        request = asset_request
+        request = self.request if respond_to?(:request)
         host = config.asset_host if defined? config.asset_host
         host ||= request.base_url if request && options[:protocol] == :request
         return unless host
@@ -340,17 +340,6 @@ def font_url(source, options = {})
         url_to_asset(source, {type: :font}.merge(options))
       end
       alias_method :url_to_font, :font_url # aliased to avoid conflicts with an font_url named route
-
-      private
-        # Get current request if self is a controller. If self is a
-        # view, check the parent controller's request.
-        def asset_request
-          if respond_to?(:request)
-            request
-          elsif respond_to?(:controller) && controller.respond_to?(:request)
-            controller.request
-          end
-        end
     end
   end
 end