Duplicate options before mutating them

2 files changed, 5 insertions, 3 deletions

diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb
index e9d4cd6c34..5caff769bb 100644
--- a/actionpack/lib/action_dispatch/http/url.rb
+++ b/actionpack/lib/action_dispatch/http/url.rb
@@ -28,6 +28,7 @@ module ActionDispatch
         end
 
         def url_for(options = {})
+          options = options.dup
           path  = options.delete(:script_name).to_s.chomp("/")
           path << options.delete(:path).to_s
 
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index d48a83e6c6..342b6ec23d 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -170,9 +170,10 @@ module ActionDispatch
 
             def call(t, args)
               if args.size == arg_size && !args.last.is_a?(Hash) && optimize_routes_generation?(t)
-                @options.merge!(t.url_options) if t.respond_to?(:url_options)
-                @options[:path] = optimized_helper(args)
-                ActionDispatch::Http::URL.url_for(@options)
+                options = @options.dup
+                options.merge!(t.url_options) if t.respond_to?(:url_options)
+                options[:path] = optimized_helper(args)
+                ActionDispatch::Http::URL.url_for(options)
               else
                 super
               end