startlxde overrides XDG_DATA_DIRS ignoring snap/flatpak .desktop entries

[lirel]

debian patches the script /usr/bin/startlxde to reset env variable XDG_DATA_DIRS to some preset directories. [1]

this bug
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=906288
can also be fixed when creating a new file

/etc/X11/Xsession.d/55debian-xdg-menus

containing
# set XDG_DATA_DIRS to include debian menu dirs

new_dirs="/usr/local/share:/usr/share:/usr/share/gdm/:/var/lib/menu-xdg/"

export XDG_DATA_DIRS
if [ -z "$XDG_DATA_DIRS" ]; then
    XDG_DATA_DIRS="${new_dirs}"
else
    XDG_DATA_DIRS="${XDG_DATA_DIRS}:${new_dirs}"
fi

and removing the patch
https://sources.debian.org/patches/lxde-common/0.99.2-3/03-menu-xdg.patch/

This would be more clean and match the behavior of snap as well as
/etc/X11/Xsession.d/20flatpak
thus rendering /usr/bin/lxsession or lxpanel able to find .desktop files placed beneath their respective XDG_DATA_DIRS paths.
Also icons are visible after this as well, that would be missing when just adding symlinks within
~/.local/share/applications .

This bug regards binary package openbox-lxde-session.

[1] https://sources.debian.org/patches/lxde-common/0.99.2-3/03-menu-xdg.patch/
[2] https://www.raspberrypi.org/forums/viewtopic.php?t=275001
[3] https://unix.stackexchange.com/questions/471327/whats-the-right-way-to-add-directories-to-xdg-data-dirs
[4] https://github.com/flatpak/ppa-flatpak/blob/ubuntu/bionic/profile/flatpak.sh a.k.a 20flatpak