Bug#1004329: ibus-mozc: The "Japanese (Mozc)" keyboard layout doesn't change to a japanese keyboard layout

[SpiceMan]

Package: ibus-mozc
Version: 2.23.2815.102+dfsg-8ubuntu1
Severity: normal

Hello, I reported this in ubuntu and was directed upstream (here).
I ran reportbug -B debian -q ibus-mozc in my ubuntu system, hence the packages being ubuntu ones.

This is not a bug, but a default configuration issue in /usr/share/ibus/components/mozc.xml

The initial ubuntu bug report is available at https://bugs.launchpad.net/ubuntu/+source/mozc/+bug/1958492

The summary is:

/usr/share/ibus/components/mozc.xml has <layout> configured as "default" instead of "jp".
This leads to the following behaviour:

1) Switching to "Japanese (Mozc)" just enables Mozc and doesn't switch to the Japanese keyboard layout
but keeps the currently used one (whatever that may be).
Switching to Japanese (no mozc) DOES switch to a japanese keyboard layout (ie: runs setxkbmap jp)
Why does a keyboard layout named "Japanese" NOT change to a japanese layout?

What's the rationale behind this?

2) The /usr/share/ibus/component/mozc.xml layout set to "default" leads to very inconsistent behaviour.
Should I have 4 different layouts besides "Japanese (Mozc)", switching to "Japanese (Mozc)" has four
possible different behaviors depending on the previously used keyboard layout.
Very inconsistent.

This debian bug report is the very example of that: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=953046

3) Japanese users don't notice because switching from Japanese (without mozc) to Japanese (Mozc)
just "works". (By chance, should they have another keyboard layout too, they would experience the
inconsistencies pointed out in 2)

4) Non-japanese users (that usually don't have the Japanese (no mozc)) layout end up being unable
to switch input modes from the keyboard with the zenkaku/hankaku key (the key to the left of the 1,
~ tilde in the us keyboard layout) because that doesn't exist in other layouts.

A lot of information on the internet suggests changing the input mode to hiragana from the menus,

but this is a workaround.
Changing to a japanese keyboard layout SHOULD let me change input modes with the japanese keyboard
layout key explicitly designed to do so.

-- System Information:
Debian Release: bullseye/sid
  APT prefers focal-updates
  APT policy: (500, 'focal-updates'), (500, 'focal-security'), (500, 'focal'), (100, 'focal-backports')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.13.0-27-generic (SMP w/8 CPU cores)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages ibus-mozc depends on:
ii  ibus                    1.5.22-2ubuntu2.1
ii  libc6                   2.31-0ubuntu9.2
ii  libglib2.0-0            2.64.6-1~ubuntu20.04.4
ii  libibus-1.0-5           1.5.22-2ubuntu2.1
ii  libprotobuf17           3.6.1.3-2ubuntu5
ii  libstdc++6              10.3.0-1ubuntu1~20.04
ii  libxcb-xfixes0          1.14-2
ii  libxcb1                 1.14-2
ii  mozc-data               2.23.2815.102+dfsg-8ubuntu1
ii  mozc-server             2.23.2815.102+dfsg-8ubuntu1
ii  tegaki-zinnia-japanese  0.3-1

ibus-mozc recommends no packages.

Versions of packages ibus-mozc suggests:
ii  mozc-utils-gui  2.23.2815.102+dfsg-8ubuntu1

-- no debconf information