Bug#1115532: libgtk-4-1: compose and dead keys not working anymore on wayland

[Frederic Peters]

Jeremy Bícha wrote:
>On Wed, Sep 17, 2025 at 5:19 PM Frederic Peters <fpeters at debian.org> wrote:
>> After upgrading from 4.18.6 to 4.20.1 compose and dead keys (e.g. ^ then e on a.
>> French layout keyboard) stopped working; typing compose ' e inputs 'e instead.
>> of é, typing ^e inputs "e" instead of "ê".
>>
>> Switching back to a X11 session restored the expected behaviour.
>
>I am unable to reproduce this issue with the information you have
>provided, using Debian Testing today.

I created a new user and it also happens for it, also I forgot to note 
this but keys are working fine in other programs (GTK3, Firefox, 
Kitty).

I went digging and I found the discussion in 
https://gitlab.gnome.org/GNOME/gtk/-/issues/7581

| On Wayland, this is entirely the responsibility of the compositor: 
| we no longer do any compose handling on the client side.

with a link to 
https://gitlab.gnome.org/GNOME/gtk/-/commit/621b7facc8b098811f659a0cba56d27e6ae39ea2

and ultimately I read the NEWS file and the note for 4.19.2:

   Note: This release makes GTK rely on the Wayland text protocol
   for input method support. For compositors without that protocol,
   you can manually set GTK_IM_MODULE=simple to get back support for
   X11-style compose sequences and dead keys.

and that's it, installing ibus fixed that for me.

ibus is already a Recommends: on gnome-shell, I don't know how GTK 
applications would behave on other compositors, and if it would make 
sense to add a recommends to gtk4 itself, I'll leave you as the judge 
for that.

Thanks,

         Fred