From 7b78da8c4cb6555caabd8af576087e60111a0c99 Mon Sep 17 00:00:00 2001
From: Nigel Banks <nigel.g.banks@gmail.com>
Date: Mon, 26 Jul 2021 15:03:49 +0100
Subject: [PATCH] Fix for undefined index warning.

---
 .../islandora_advanced_search/src/Form/AdvancedSearchForm.php   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php b/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php
index 513f20b6..c00ce566 100644
--- a/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php
+++ b/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php
@@ -392,7 +392,7 @@ class AdvancedSearchForm extends FormBase {
       $terms[] = AdvancedSearchQueryTerm::fromUserInput($term);
     }
     $terms = array_filter($terms);
-    $recurse = filter_var($values['recursive'], FILTER_VALIDATE_BOOLEAN);
+    $recurse = filter_var(isset($values['recursive']) ? $values['recursive'] : FALSE, FILTER_VALIDATE_BOOLEAN);
     $route = $this->getRouteName($form_state);
     $advanced_search_query = new AdvancedSearchQuery();
     return $advanced_search_query->toUrl($this->request, $terms, $recurse, $route);