bug#53173: 28.0.91; preedit style for X Input Method is not supported?

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 53173-done@debbugs.gnu.org
>> Date: Tue, 11 Jan 2022 16:12:01 +0800
>> From:  Po Lu via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> Hirofumi Kosaka <kosaka@rworks.jp> writes:
>> 
>> > Hello all,
>> >
>> > The X Server that I use supports 'over-the-spot' for XIM (X Input
>> > Method) preedit style, but the pretest version forces root window
>> > style, that is the most basic style but not good enough for us CJK
>> > users.
>> 
>> I completely agree.  Someone deleted the code for other styles to fix a
>> bug, instead of fixing the real cause of that problem, which I did on
>> master.
>> 
>> > Emacs 27.2 (or earlier) works fine for it, but the pretest version
>> > seems to ignore available preedit styles (X server provides) or so.
>> 
>> It's too late to change this inside the pretests, but it should work on
>> master.

> Which commit fixed that on master?

The two commits that introduced the ability to use preedit text in XIM
input methods, and to change the preedit style.

They're definitely not safe to backport, IMO, just look at the recent
bug reports related to fcitx5 (which used to not work at all, but now
has display bugs, probably due to a problem in their code.)