csd-keyboard fights IBus XKB layout changes (kr layout reverted)

[wintrover]

Issue: Cinnamon csd-keyboard fights IBus XKB layout changes (kr layout)

Description

When IBus activates the hangul engine, it changes the XKB layout to kr (because the hangul engine XML declares <layout>kr</layout>). Cinnamon's csd-keyboard daemon, which only knows about the user's configured input sources [('xkb', 'us')], detects this unexpected layout change and reverts it. This causes a "tug of war" between IBus and Cinnamon, breaking Korean input.

Environment

• Ubuntu 24.04 (noble)
• Cinnamon 6.6.7 desktop / X11
• IBus 1.5.29-2
• ibus-hangul 1.5.5-2build2

Steps to Reproduce

1. Set Cinnamon input sources to only [('xkb', 'us')]:

   gsettings set org.cinnamon.desktop.input-sources sources "[('xkb', 'us')]"

2. Activate ibus-hangul engine
3. IBus changes layout to kr → Cinnamon reverts to us → Korean input breaks

Workaround

Add kr to Cinnamon's input sources so csd-keyboard doesn't reject the layout change:

gsettings set org.cinnamon.desktop.input-sources sources "[('xkb', 'us'), ('xkb', 'kr')]"

Expected Behavior

Input method engines should be able to change XKB layouts without interference from the desktop environment's keyboard daemon. When IBus is handling input, Cinnamon's layout management should yield.

Actual Behavior

The desktop environment's keyboard daemon and the input method framework conflict over XKB layout control, silently breaking input.

[wintrover]

Root cause identified on the ibus-hangul side

The root cause of this conflict is that /usr/share/ibus/component/hangul.xml declares <layout>kr</layout> and <layout_variant>kr104</layout_variant>. When IBus activates the hangul engine, it calls setxkbmap kr kr104, triggering the fight with csd-keyboard.

Key finding: libhangul does its own key→jamo mapping independently of XKB. The hangul engine works correctly with the us layout — it does NOT need the XKB layout to be kr.

Workaround (applied successfully on my system):

sudo sed -i '/\/layout.*kr/d' /usr/share/ibus/component/hangul.xml
ibus restart

After this, setxkbmap -query shows layout: us even when hangul engine is active, Korean input works normally, and csd-keyboard has no unexpected layout change to fight.

Related ibus-hangul issue: libhangul/ibus-hangul#136 — proposing to remove the unnecessary <layout> declaration upstream.

This is a two-sided bug: ibus-hangul should not override the XKB layout unnecessarily, AND csd-keyboard should tolerate IM-initiated layout changes. But the ibus-hangul side fix is the more impactful one since libhangul genuinely does not need the kr layout.