Detection of record_id does not work in tx_dlf_document->getTitledata()

[Sebastian Meyer]

The record_id represents the unique identifier for the METS record. Therefore it should be encoded in mets:mets[@OBJID] or mets:mets[@ID] (because mods:recordIdentifier represents the identifier of the MODS record, but not the whole file).

When saving a document, tx_dlf_document->getTitledata() is called, but takes its information only from MODS. Therefore it can't detect the record_id of the METS file correctly.