LDAP: add error handling for failed searches

apps/user_ldap/lib/access.php

@@ -515,6 +515,11 @@ abstract class Access {
 		$pagedSearchOK = $this->initPagedSearch($filter, $base, $attr, $limit, $offset);
 
 		$sr = ldap_search($link_resource, $base, $filter, $attr);
+		if(!$sr) {
+			\OCP\Util::writeLog('user_ldap', 'Error when searching: '.ldap_error($link_resource).' code '.ldap_errno($link_resource), \OCP\Util::ERROR);
+			\OCP\Util::writeLog('user_ldap', 'Attempt for Paging?  '.print_r($pagedSearchOK, true), \OCP\Util::ERROR);
+			return array();
+		}
 		$findings = ldap_get_entries($link_resource, $sr );
 		if($pagedSearchOK) {
 			\OCP\Util::writeLog('user_ldap', 'Paged search successful', \OCP\Util::INFO);