Unicode in imported file names OK with docs, garbled with files

[madduck]

I imported a document named 2023-08-18-vWellhöner_Vertrag_Arbeitgeberwechsel_ENTWURF.odt using the docs-importer. The created document is fine, but the contained file name doesn't seem to support Unicode: The created file uses ö instead of ö, but as you can see, it's fine for the document.