Desktop environment list doesn't show all DEs

[George Pîrlea]

When you log in as a user, you can select which desktop environment to log into (Gnome, KDE, Xfce, etc.) When you have a lot of desktop environments installed, however, the list of DEs runs off the screen and can't be scrolled down (neither with the mouse wheel, nor with the arrow keys).

See the attached screenshot. Note that at the bottom of the list you can still see that there are more DEs to be displayed, but there's simply no space left.

You can select all the DEs on the list, though, by cycling through them with TAB, but you can't see what you're selecting.

EXPECTED BEHAVIOUR: you can scroll through the list and see every item
ACTUAL BEHAVIOUR: you can't see all the DEs in the list