TYPO3 Core

I noticed $GLOBALS['LANG'] may not be initialized in some contexts, this is also mentioned in LanguageService:

 * Usually this is injected into $GLOBALS['LANG'] when in backend or CLI context, and
 * populated by the current backend user. Don't rely on $GLOBAL['LANG'] in frontend, as it is only
 * available in certain circumstances!
 * In Frontend, this is also used to translate "labels", see TypoScriptFrontendController->sL()
 * for that.

We are not in Frontend, but somehow it is not initialized in my case either (when running an Upgrade Wizard in the BE).

I have an Upgrade wizard which wants to migrate some Flexforms. I use FlexFormTools::cleanFlexFormXML which instantiate the DataStructureIdentifierHook which will throw an exception in the constructor because $GLOBALS['LANG'] is null.

It calls

• TYPO3\CMS\Core\Configuration\FlexForm\FlexFormTools::cleanFlexFormXML
• which calls the TYPO3\CMS\Form\Hooks\DataStructureIdentifierHook constructor
• which calls $this->getLanguageService()
• which tries to return $GLOBALS['LANG']

EXT:form is installed here but it is not relevant at all to the Flexforms which are to be converted.

see attached stackdump file