As many of mans known, currently solution with
mimetypes.cache does not work.
Firefox currently uses D-bus to activate service
org.freedesktop.FileManager1 to handle "Open containing folder" action and so on.
In case, when many service files installed (nemo and dolphin, for example) and no daemon running (
dolphin --daemon or
/usr/bin/nemo --no-default-window) there is no clean way to select preferred file manager.
On my system looks like selected first service file sorted in alphabetical order. So, on KDE system Firefox handles folders via Nemo.
I see currently at least two solutions, both seems as hack:
make a symlink:
ln -s /usr/share/dbus-1/services/org.kde.dolphin.FileManager1.service /usr/share/dbus-1/services/00_preferred_org.freedesktop.FileManager1.service
(don't forget to kill currently running file manager daemons or relogin session)
Early pre-run needed
~/.profileunder proper conditions.
It there more clean way?
PS try to execute file manager without Firefox:
dbus-send --session \ --print-reply \ --dest=org.freedesktop.FileManager1 \ /org/freedesktop/FileManager1 \ org.freedesktop.FileManager1.ShowFolders \ array:string:"file:/" string:""