Merge pull request #2753 from projectblacklight/backport-2752

Pass a SearchState instance when building the advanced search form search service

app/controllers/concerns/blacklight/catalog.rb

@@ -60,9 +60,7 @@ def show
   end
 
   def advanced_search
-    empty_service = search_service_class.new(config: blacklight_config, user_params: {}, **search_service_context)
-
-    (@response, _deprecated_document_list) = empty_service.search_results
+    (@response, _deprecated_document_list) = blacklight_advanced_search_form_search_service.search_results
   end
 
   # get a single document from the index
@@ -334,4 +332,14 @@ def handle_request_error(exception)
     flash[:notice] = flash_notice
     redirect_to search_action_url
   end
+
+  def blacklight_advanced_search_form_search_service
+    form_search_state = search_state_class.new(blacklight_advanced_search_form_params, blacklight_config, self)
+
+    search_service_class.new(config: blacklight_config, search_state: form_search_state, user_params: form_search_state.to_h, **search_service_context)
+  end
+
+  def blacklight_advanced_search_form_params
+    {}
+  end
 end