[BUGFIX] Explicitly declare nullable function parameters

[stweil]

PHP 7.1 added support for nullable types, but they could be declared implicitly. PHP 8.4 deprecates implicitly nullable types.

Using an explicit declaration avoids several warnings with PHP 8.4.

[stweil]

I expect that there are more nullable types which should be declared explicitly, but until now only the 3 locations which are fixed here triggered warnings in my tests.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 0.00%. Comparing base (95a1ff5) to head (30149cf).
Report is 1 commits behind head on main.

Additional details and impacted files

@@     Coverage Diff      @@
##   main   #1505   +/-   ##
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[stweil]

I expect that there are more nullable types which should be declared explicitly, but until now only the 3 locations which are fixed here triggered warnings in my tests.

These code lines need similar fixes:

Classes/Common/DocumentAnnotation.php:    protected function getAudioPagesByFileId($fileId, $range = null)
Classes/Common/DocumentAnnotation.php:    protected function getMeasurePagesByFileId($fileId, $range = null)
Classes/Common/Solr/Solr.php:    public static function getInstance($core = null): Solr
Classes/Common/Solr/SolrSearch.php:    public function __construct(DocumentRepository $documentRepository, $collections, array $settings, array $searchParams, QueryResult $listedMetadata = null, QueryResult $indexedMetadata = null)
Classes/Controller/Backend/NewTenantController.php:    protected function htmlResponse(?string $html = null): ResponseInterface
Classes/Controller/NavigationController.php:    public function pageSelectAction(PageSelectForm $pageSelectForm = null): ResponseInterface
Classes/Controller/PageViewController.php:    public function convertMeasureOrPage($document, $measure = null, $page = null)
Classes/Domain/Repository/DocumentRepository.php:    public function findSolrByCollection(Collection $collection, $settings, $searchParams, $listedMetadata = null, $indexedMetadata = null)
Classes/Domain/Repository/DocumentRepository.php:    public function findSolrByCollections($collections, $settings, $searchParams, $listedMetadata = null, $indexedMetadata = null): SolrSearch
Classes/Domain/Repository/DocumentRepository.php:    public function findSolrWithoutCollection($settings, $searchParams, $listedMetadata = null, $indexedMetadata = null): SolrSearch
Classes/Domain/Repository/DocumentRepository.php:    private function findSolr($collections, $settings, $searchParams, $listedMetadata = null, $indexedMetadata = null): SolrSearch
Classes/Task/BaseAdditionalFieldProvider.php:    protected function getSolrField(int $solr, int $pid = null): array
Classes/Task/BaseAdditionalFieldProvider.php:    private function getSolrCores(int $pid = null): array
Classes/Validation/AbstractDlfValidationStack.php:    protected function addValidator(string $className, string $title, bool $breakOnError = true, array $configuration = null): void

[sebastian-meyer]

Since you identified more files which need adjustments: should I wait for you to fix those as well or do you want to open separate PRs for those?

[stweil]

No, please merge. I currently struggle with the broken viewer which is much more important (see #1536 (comment)).