WorkspaceAwareRecordService->getSingle NULL Result

[timschenk]

When the parent page is hidden, I get the following error message, when previewing my sub-page of this page:

Oops, an error occurred!
Argument 1 passed to FluidTYPO3\Flux\Provider\AbstractProvider::getParentFieldName() must be of the type array, null given, called in /var/www/qa-extranet-aerticket_de/releases/20190506104214/web/typo3conf/ext/fluidpages/Classes/Provider/PageProvider.php on line 421

Reason seems to be: (WorkspaceAwareRecordService) $this->recordService->getSingle returns NULL, when the parent page is hidden.

Expected behavior from my point of view should be: A visible page should be visible in frontend even when a parent page is hidden. This behavior should especially work when a backend user is logged in.

TYPO3 v8.7.24
fluidpages v4.3.0

Might be related to #392 or #405