Downloaded RDF files gets opened in epiphany when opening them from the download popover, then downloaded again as Epiphany can't show them

Steps

• Download this RDF sample file
• open the downloads popover
• click the file in the list

Current behaviour

The file is opened in epiphany (as a new opened tab indicates), but epiphany can't show it so it downloads it again.

Expected behaviour

Epiphany doesn't do this and just opens an external program instead.

Interestingly when I run xdg-mime query filetype foobar.rdf, it prints application/rdf+xml, but with xdg-mime query default application/rdf+xml it doesn't show any app (not even epiphany). So I assume that either Epiphany opens the file in itself when there's no app to open it, or that it's related to epiphany having text/xml as mime type handler in the desktop file.

Reproducable with both stable epiphany from flathub and the gnome-nightly one.