[TYPO3-english] Custom content elment: Images (Not flexform) get duplicated if translation fails

[redacted user]

Hey,

I have a problem with a custom content element which extends tt_content
in 6.2.17:

1. Create content element with FAL image in default language (The
tt_content image field is used, NOT a flexform)
2. Try to translate the CE with an translator account who doesn't have
access to this CType (sadly the "Copy default content elment button"
still shows up)
3. TYPO3 tries to create a translated CE but fails with "newlog()]
recordEditAccessInternals() check failed. [ERROR: authMode
"explicitAllow" failed for field "CType" with value..."
4. It's correct that TYPO3 throws this error, but it seems that this
happens too late. The FAL image was already copied to the new language
and shows up as duplicate in the default language now

M.e the problem is in
\TYPO3\CMS\Core\DataHandling\DataHandler->process_datamap().
The tables which need an update/new entries are processed one after
another and access check happens only for the current table.
So if an error occurs in the last table (In $orderOfTables) the already
proccessed tables need some kind of rollback.

Is this a known bug or did I configure something incorrectly?

Thanks for your help!

BR,
Chris