Full-width space inserted instead of language switch on pressing Super+Space in Hiragana Input mode in Fedora 39

[earlydogs]

Description

In Fedora 39, when the input mode is set to Hiragana and the language switch key (Super+Space) is pressed, it fails to switch languages and instead inserts a full-width space. This issue occurs during input in Terminal applications but does not happen in browser applications like Chrome. Initially thought to be a Fedora 39 bug, this issue does not occur with other input sources (such as Anthy), leading to this report.

Steps to reproduce

1. Set up Fedora 39.
2. Install ibus-mozc with sudo dnf install ibus-mozc.
3. Restart the operating system.
4. Add Japanese (Mozc) to Input sources through the Settings menu.
5. Switch to Mozc by pressing Super + Space.
6. Change the Mozc setting to Hiragana in Input Mode.
7. In a terminal application, press Super + Space.

Version or commit-id

Installed Packages
Name : ibus-mozc
Version : 2.29.5111.102
Release : 3.fc39
Architecture : x86_64
Size : 1.1 M
Source : mozc-2.29.5111.102-3.fc39.src.rpm
Repository : @System
From repo : fedora
Summary : The mozc engine for IBus input platform
URL : https://github.com/google/mozc
License : BSD-3-Clause AND Apache-2.0 AND Unicode-DFS-2015 AND NAIST-2003
Description : Mozc is a Japanese Input Method Editor (IME) designed for
: multi-platform such as Chromium OS, Windows, Mac and Linux.
:
: This package contains the Input Method Engine for IBus.

Installed Packages
Name : mozc
Version : 2.29.5111.102
Release : 3.fc39
Architecture : x86_64
Size : 23 M
Source : mozc-2.29.5111.102-3.fc39.src.rpm
Repository : @System
From repo : fedora
Summary : A Japanese Input Method Editor (IME) designed for multi-platform
URL : https://github.com/google/mozc
License : BSD-3-Clause AND Apache-2.0 AND Unicode-DFS-2015 AND NAIST-2003
Description : Mozc is a Japanese Input Method Editor (IME) designed for
: multi-platform such as Chromium OS, Windows, Mac and Linux.

Environment

• OS: Fedora 39

[hiroyuki-komatsu]

Would you also check other modifier keys rather than Super to switch the input source (e.g. Shift + Space) ?

[earlydogs]

Yes. Even when set to Shift+Space instead of Super+Space, a full-width space is entered.

[earlydogs]

The issue was caused by Wayland. Disabling Wayland resolved the issue. Please close this thread. Thank you.

[hiroyuki-komatsu]

Thank you for the update.
I marked your comment as the answer of this Q&A.

[phoepsilonix]

PR #1059 resolves this issue. I tested it on Manjaro Linux(GNOME/Wayland) and confirmed that it works well.