The issue is that ibus-mozc drops modifier keys other than Shift, Ctrl,
and Alt in KeyEventHandler. When hitting Super+Space, Mozc sees a bare
Space key, consumes the event, and emits a full-width Japanese space
(' ') instead of letting Mutter switch input sources.Upstream Mozc fixed this in 2.30 (PR #1059, commit ca1df21), but Ubuntu packages are still on 2.29.5160.102. Attached is a debdiff adding debian/patches/0019-ignore-super-and-extra- modifiers.patch, backporting the upstream fix (+ IBUS_SUPER_MASK coverage for Wayland compositors). Test Case 1. Add Japanese (Mozc) in GNOME Settings -> Keyboard. 2. Switch to Japanese input (Hiragana mode). 3. Press Super+Space. - Without patch: Inserts a full-width space ' ' in the current input field; layout does not switch. - With patch: Layout switches back to English / previous source cleanly. Regression Potential None expected. KeyEventHandler only returns false early if MOD3/MOD4/MOD5/SUPER/HYPER/META bits are present. Mozc has no hotkeys bound to Super. ** Patch added: "debdiff backporting Super+Space fix for mozc 2.29" https://bugs.launchpad.net/ubuntu/+source/mozc/+bug/2091631/+attachment/5999884/+files/mozc_super_space.debdiff -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2091631 Title: Default Super+Space hotkey doesn't change JP layout back to English To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mozc/+bug/2091631/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
