Disabling Unicode input with C-U

[Brad Neimann]

Hi all,

Recently I started using m17n with IBus, and am very happy with the
resulting experience. However, one point annoys me: whenever I press
C-U, a Unicode character selector appears with the text 'U+',
expecting me to input a hexadecimal character code. I find this highly
inconvenient, especially when using applications which use C-u as a
keyboard shortcut (e.g. Vim).

Is there any way to disable this behaviour of C-U? IBus doesn't appear
to have any relevant options, and there seems to be no way to
configure m17n indepedently.  I've tried looking through the m17n
source code, but that didn't help. As far as I can tell the C-U key
combination comes from the predefined Unicode input method, but I
can't figure out why it's included in the input methods I am using.

For reference, I am using EndeavourOS (so basically Arch Linux), with
package versions m17n-db-1.8.0-3, m17n-lib-1.8.0-13,
ibus-m17n-1.4.18-1 and ibus-1.5.27-1. I use a custom keyboard layout
[0], but have confirmed that C-U exhibits the same behaviour with
m17n's predefined keyboard layouts too.

Regards,
Brad

[0] Available at https://github.com/bradrn/Conkey. The relevant .mim
keyboard layout can be found on the 'Releases' page.