See https://mail.kde.org/pipermail/distributions/2024-February/001480.html. """ In plasma 6 we are moving away from the KDE-specific InitialPreference keys in desktop files [1] and instead install a mimeapps list [2] as per [3]. You'll want to make sure that you install suitable mimeapps.list(s) to set up things correctly for 3rd party apps such as libreoffice. [1] https://invent.kde.org/frameworks/kservice/-/merge_requests/181 [2] https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/2030 [3] https://specifications.freedesktop.org/mime-apps-spec/mime-apps-spec-1.0.1.html """
Fedora did https://pagure.io/fedora-kde/SIG/issue/455.
Note that kde-plasma/plasma-desktop currently installs its own with upstream preferences that we should either drop or override via /etc/xdg. Probably the latter.
See also https://github.com/mgorny/mimelist-gen that lets you feed it a list of your preferred desktop files, spitting out the ${XDG_MENU_PREFIX}mimeapps.list (or was it ${XDG_SESSION_DESKTOP}-mimeapps.list ?) from it. Should allow multiple apps per MIME type based on the desktop files order.