@@ -577,6 +577,7 @@ def search():
577577 if output_format == 'html':
578578 return render(
579579 'index.html',
580+ advanced_search=request.preferences.get_value('advanced_search')
580581 selected_categories=get_selected_categories(request.preferences, request.form),
581582 )
582583 else:
@@ -611,7 +612,10 @@ def search():
611612 return redirect(result_container.redirect_url)
612613
613614 # UI
614− advanced_search = request.preferences.get_value('advanced_search')
615+ # 'q' in request.from, possible value from request.form.get('advanced_search'):
616+ # * 'on': the checkbox is checked
617+ # * None: the checkbox is unchecked or request is sent from opensearch.xml
618+ advanced_search = request.form.get('advanced_search')
615619
616620 # Server-Timing header
617621 request.timings = result_container.get_timings()