bug#60711: Compose fails to generate ≤ and ≥ (only those two! and only in emacs!)

[Marcin Kasperski]

Half-eureka.

I found another application which also exhibits problematic behaviour
(fails to display ≥ / ≤  and shows this strange popup).

xterm

At the same time gnome-terminal, konsole, terminator, xfce4-terminal are OK,
compose works properly in them and there is no popup.

So looks like „raw” X11 somehow misworks, while every desktop API
manages to smooth it towards proper behaviour.