* Fixing dual Plasma/Xfce installations
Plasma and Xfce both define the ~org.freedesktop.Notifications~ D-BUS
service.  That leads to all kinds of fun ([[https://bugs.kde.org/show_bug.cgi?id=381693][KDE bug]]; [[https://bugzilla.redhat.com/show_bug.cgi?id=484945][Red Hat bug]]); on my
machine, it causes Plasma sessions to use xfce4-notifyd instead of
Plasma's own notification mechanism.

[[https://kevinlocke.name/bits/2020/04/12/resolving-desktop-notifications-dbus-service-conflicts/][Kevin Locke]] explains how to solve the issue by defining a third
~org.freedesktop.Notifications~ service in a higher-priority user
directory, which runs a command that will determine the current
desktop environment and start the appropriate notification daemon.  In
~~/.local/share/dbus-1/services/org.freedesktop.Notifications.service~:

#+begin_src conf-desktop
[D-BUS Service]
Name=org.freedesktop.Notifications
Exec=/bin/sh -c "~/.local/lib/meta-notify"
#+end_src

This gentleman suggests relying on the ~XDG_SESSION_DESKTOP~ variable
to find out which DE is running; unfortunately, for some reason if I
log into Plasma first, then into Xfce, this variable (as well as
~XDG_CURRENT_DESKTOP~ and ~DESKTOP_SESSION~) keeps saying "KDE" when
the script runs.

(I think this might be caused by Xfce's [[https://gitlab.xfce.org/atomsymbol/xfce4-session/-/blob/xfce4-session-4.14.2/scripts/xinitrc.in.in#L19][xinitrc]] not setting these
variables if they are not empty, but they *are* set when I look at
them in a shell once logged in, so… 🤷)

Thus my version of ~~/.local/lib/meta-notify~ falls back on the window
managers:

#+begin_src sh
#!/bin/sh

wm=$(wmctrl -m | grep '^Name:' | cut -f2- -d' ')

case ${wm} in
    KWin)
        exec /usr/bin/plasma_waitforname org.freedesktop.Notifications
        ;;
    Xfwm4)
        exec dbus-send --session                                            \
                       --dest=org.freedesktop.systemd1                      \
                       /org/freedesktop/DBus                                \
                       org.freedesktop.systemd1.Activator.ActivationRequest \
                       string:xfce4-notifyd.service
        ;;
    *)
        /usr/bin/logger -t $(basename "$0") Unknown window manager \"${wm}\"
        exit 1
esac
#+end_src