TYPO3 Core

*Summary:
If a translated element has been assigned to another default entry, a new translation cannot be created from the original default entry because the l10n_source field of the translated element does not change.

1. Editor creates a translation of a content element
2. Editor deletes the relation within the translated element to the default element
3. Editor sets a new relation to another content element
4. Editor wants to create a new translation of the first content element. This is not possible because the two fields t3_origuid and l10n_source of the first translation are not updated in the database, only the field l10n_parent is updated.