This re-applies a chunk from commit e63262d49d which was
accidentally lost when upstreaming the commit to xdgmime (as
https://gitlab.freedesktop.org/xdg/xdgmime/-/merge_requests/10).
The upstreamed commit was then re-backported to GLib as a1bfe899ab,
without the missing chunk.
The missing chunk is potentially causing incorrect content type results
for `file://` URIs when used from webkitgtk.
Thanks to Stephen Jung and Michael Catanzaro for investigating.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #2639
7ec351e3f4