[Bug 54318] Rich Edit inserts newly composed text at wrong position when system IME composition ends while a selection is active

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54318

--- Comment #1 from Jinoh Kang  ---
Steps to reproduce (expanded):

1. Activate fcitx5 (Hangul).
2. Open write.exe, or any other application with a Rich Edit control.
3. Give focus to the Rich Edit control.
4. Enter the following text: "[ABCXYZ]"
5. Select the following text from beginning to end: "ABC"
6. Compose a character.

Note that selecting the text in the reverse order does not appear to exhibit
the symptom.