drop || test for cases that do not need it

Author: tenderlove

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -580,11 +580,13 @@ def define_generate_prefix(app, name)
             app.routes.define_mounted_helper(name)
             app.routes.extend Module.new {
               def mounted?; true; end
-              define_method :_generate_prefix do |options|
+              define_method :find_script_name do |options|
+                super(options) || begin
                 prefix_options = options.slice(*_route.segment_keys)
                 # we must actually delete prefix segment keys to avoid passing them to next url_for
                 _route.segment_keys.each { |k| options.delete(k) }
                 _routes.url_helpers.send("#{name}_path", prefix_options)
+                end
               end
             }
           end

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -641,8 +641,8 @@ def optimize_routes_generation?
         !mounted? && default_url_options.empty?
       end
 
-      def _generate_prefix(options)
-        nil
+      def find_script_name(options)
+        options.delete :script_name
       end
 
       # The +options+ argument must be a hash whose keys are *symbols*.
@@ -659,7 +659,7 @@ def url_for(options)
         recall  = options.delete(:_recall)
 
         original_script_name = options.delete(:original_script_name)
-        script_name = options.delete(:script_name) || _generate_prefix(options)
+        script_name = find_script_name options
 
         if script_name && original_script_name
           script_name = original_script_name + script_name