drop || test for cases that do not need it

1 files changed, 3 insertions, 1 deletions

diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index d75ea9394c..58c7f5330e 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -580,11 +580,13 @@ module ActionDispatch
             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