From 66cf807cddade32960dd87964d29aba18ed3e282 Mon Sep 17 00:00:00 2001
From: Ralf Becker <RalfBecker@outdoor-training.de>
Date: Tue, 5 Oct 2021 16:35:27 +0200
Subject: [PATCH] fix PHP 8.0 Error: Argument #2 ($array) must be of type
 array, null given

---
 addressbook/inc/class.addressbook_ui.inc.php | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/addressbook/inc/class.addressbook_ui.inc.php b/addressbook/inc/class.addressbook_ui.inc.php
index 242d13eaf6..b54dd808e3 100644
--- a/addressbook/inc/class.addressbook_ui.inc.php
+++ b/addressbook/inc/class.addressbook_ui.inc.php
@@ -1736,9 +1736,13 @@ class addressbook_ui extends addressbook_bo
 		if (isset($this->grouped_views[(string) $query['grouped_view']]))
 		{
 			// we have a grouped view, reset the advanced search
-			if(!$query['search'] && $old_state['advanced_search']) $query['advanced_search'] = $old_state['advanced_search'];
+			if (empty($query['search']) && !empty($old_state['advanced_search']))
+			{
+				$query['advanced_search'] = $old_state['advanced_search'];
+			}
 		}
-		elseif(!$query['search'] && array_key_exists('advanced_search',$old_state))	// eg. paging in an advanced search
+		// eg. paging in an advanced search
+		elseif(empty($query['search']) && is_array($old_state) && array_key_exists('advanced_search', $old_state))
 		{
 			$query['advanced_search'] = $old_state['advanced_search'];
 		}