From 1c606b62e236637df26641669e4f42e205c851b2 Mon Sep 17 00:00:00 2001
From: Lukas Niestroj <niestrojlukas@gmail.com>
Date: Mon, 2 Jan 2023 15:02:25 +0100
Subject: [PATCH 1/2] [BUGFIX] add empty string as fallback

ensure a string is always returned, even if the query does not exist
---
 .../Facets/OptionBased/QueryGroup/QueryGroupUrlDecoder.php      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Classes/Domain/Search/ResultSet/Facets/OptionBased/QueryGroup/QueryGroupUrlDecoder.php b/Classes/Domain/Search/ResultSet/Facets/OptionBased/QueryGroup/QueryGroupUrlDecoder.php
index 16641b4db0..f423d2ba2f 100644
--- a/Classes/Domain/Search/ResultSet/Facets/OptionBased/QueryGroup/QueryGroupUrlDecoder.php
+++ b/Classes/Domain/Search/ResultSet/Facets/OptionBased/QueryGroup/QueryGroupUrlDecoder.php
@@ -37,6 +37,6 @@ class QueryGroupUrlDecoder implements FacetUrlDecoderInterface
      */
     public function decode(string $value, array $configuration = []): string
     {
-        return $configuration[$value . '.']['query'];
+        return $configuration[$value . '.']['query'] ?? '';
     }
 }

From 99143fc4cb8cadb81a8cb7af6acbc59b4cc51636 Mon Sep 17 00:00:00 2001
From: Markus Friedrich <markus.friedrich@dkd.de>
Date: Mon, 27 Mar 2023 13:42:13 +0200
Subject: [PATCH 2/2] [TASK] Handle invalid facet options

Invalid filter options will lead to Solr errors and exceptions
in frontend. This commit adds an additional check, ensuring invalid
filter options will not be applied.

A log entry will help the website administrator to solve the
issue.
---
 Classes/Query/Modifier/Faceting.php | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/Classes/Query/Modifier/Faceting.php b/Classes/Query/Modifier/Faceting.php
index 8355484855..b80415f5a9 100644
--- a/Classes/Query/Modifier/Faceting.php
+++ b/Classes/Query/Modifier/Faceting.php
@@ -29,6 +29,8 @@
 use ApacheSolrForTypo3\Solr\Domain\Search\SearchRequestAware;
 use ApacheSolrForTypo3\Solr\System\Configuration\TypoScriptConfiguration;
 use InvalidArgumentException;
+use TYPO3\CMS\Core\Log\LogManager;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
 
 /**
  * Modifies a query to add faceting parameters
@@ -155,8 +157,11 @@ protected function addFacetQueryFilters(array $resultParameters, bool $keepAllFa
             $facetConfiguration = $allFacets[$facetName . '.'];
             $tag = $this->getFilterTag($facetConfiguration, $keepAllFacetsOnSelection);
             $filterParts = $this->getFilterParts($facetConfiguration, $facetName, $filterValues);
-            $operator = (($facetConfiguration['operator'] ?? null) === 'OR') ? ' OR ' : ' AND ';
-            $facetFilters[$facetName] = $tag . '(' . implode($operator, $filterParts) . ')';
+
+            if (!empty($filterParts)) {
+                $operator = (($facetConfiguration['operator'] ?? null) === 'OR') ? ' OR ' : ' AND ';
+                $facetFilters[$facetName] = $tag . '(' . implode($operator, $filterParts) . ')';
+            }
         }
 
         return $facetFilters;
@@ -208,7 +213,13 @@ protected function getFilterParts(array $facetConfiguration, string $facetName,
             }
 
             $filterValue = $filterEncoder->decode($filterValue, $filterOptions);
-            $filterParts[] = $facetConfiguration['field'] . ':' . $filterValue;
+            if (($facetConfiguration['field'] ?? '') !== '' && $filterValue !== '') {
+                $filterParts[] = $facetConfiguration['field'] . ':' . $filterValue;
+            } else {
+                /** @var $logger \TYPO3\CMS\Core\Log\Logger */
+                $logger = GeneralUtility::makeInstance(LogManager::class)->getLogger(__CLASS__);
+                $logger->warning('Invalid filter options found, skipping.', ['facet' => $facetName, 'configuration' => $facetConfiguration]);
+            }
         }
 
         return $filterParts;