TYPO3 Core

In RFC #18115 a 5th parameter was added to t3lib_parsehtml::substituteMarkerArray() to remove unused markers. It does so with the following line:

$content = preg_replace('/'.preg_quote($wrapArr⁰).'([A-Z0-9_-|]*)'.preg_quote($wrapArr¹).'/is', '', $content);

This will fail if the marker wrap is not defined, because the default wrap is ### where the $wrapArr is empty when no wrap is passed to this method.

The solution is to initialise $wrapArr when no marker wrap argument was passed.

(issue imported from #M8637)