Safely join new parameters when switching the language

Fixes CODEOCEAN-JY

app/helpers/authenticated_url_helper.rb

@@ -82,8 +82,6 @@ module AuthenticatedUrlHelper
       TOKEN_PARAM
     end
 
-    private
-
     def add_query_parameters(url, parameters)
       parsed_url = URI.parse url
 
@@ -100,6 +98,8 @@ module AuthenticatedUrlHelper
       url
     end
 
+    private
+
     def remove_query_parameters(url, parameters)
       parsed_url = URI.parse url
 

app/views/application/_locale_selector.html.slim

@@ -4,4 +4,4 @@ li.nav-item.dropdown
     span.caret
   ul.dropdown-menu.p-0.mt-1 role='menu'
     - I18n.available_locales.sort_by { |locale| t("locales.#{locale}") }.each do |locale|
-      li = link_to(t("locales.#{locale}"), url_for(request.query_parameters.merge(locale: locale)), 'data-turbolinks' => "false", class: 'dropdown-item')
+      li = link_to(t("locales.#{locale}"), AuthenticatedUrlHelper.add_query_parameters(request.url, locale: locale), 'data-turbolinks' => "false", class: 'dropdown-item')