TYPO3 Core

If changing fields which reference MM relations, sys_history will log these changes by storing a different relation count instead of the differences of referenced records. A rollback will therefore restore the wrong relations (relation to a record with uid=old relation count wil be restored) and the record's history shows wrong information.

Attached patch corrects the referenced uids in sys_history and enables restoring the correct relations as well as providing a correct history of MM changes. It of course can't restore information contained within these MM-relations (like sorting), since MM-relations traditionally have no TCA definition (no deleted flag, no logging...).

This is related to #17106, which is incorporated here.

(issue imported from #M12688)