Fix URL params breaking flow recognition

ee/app/helpers/ee/registrations_helper.rb

@@ -3,7 +3,9 @@
 module EE
   module RegistrationsHelper
     def in_paid_signup_flow?
-      experiment_enabled?(:paid_signup_flow) && session['user_return_to'] == new_subscriptions_path
+      experiment_enabled?(:paid_signup_flow) &&
+        (redirect_to = session['user_return_to']) &&
+        URI.parse(redirect_to).path == new_subscriptions_path
     end
   end
 end

ee/spec/helpers/ee/registrations_helper_spec.rb

@@ -7,10 +7,12 @@ describe EE::RegistrationsHelper do
 
   describe '#in_paid_signup_flow?' do
     where(:user_return_to_path, :paid_signup_flow_enabled, :expected_result) do
-      '/-/subscriptions/new' | true  | true
-      '/-/subscriptions/new' | false | false
-      '/'                    | true  | false
-      '/'                    | false | false
+      '/-/subscriptions/new?plan_id=bronze_plan' | true  | true
+      '/-/subscriptions/new?plan_id=bronze_plan' | false | false
+      '/foo'                                     | true  | false
+      '/foo'                                     | false | false
+      nil                                        | true  | nil
+      nil                                        | false | false
     end
 
     with_them do