TYPO3 Core

\TYPO3\CMS\Fluid\ViewHelpers\Format\HtmlViewHelper->renderStatic() misses a call to \TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer->start() after instantiation and before it passes the content to parseFunc.

Because of this the $hookObjects of ContentObjectRenderer are not initialized during the processing with parseFunc in f.format.html. This makes it impossible to apply own TypoScript cObjects via $this->cObjHookObjectsRegistry (like the XSLT or XPATH content objects for example) or own extensions to stdWrap functions via $this->stdWrapHookObjects.

The solution is to call $contentObject->start([], '') after instantiation (just like it's done in TYPO3\CMS\Fluid\ViewHelpers\Link\TypolinkViewHelper).

This issue applies to all versions from 7.6 onwards.