[Bug 54965] New: Rich Edit erroneously moves the cursor to the end of text when system IME composition ends

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54965

Bug ID: 54965
           Summary: Rich Edit erroneously moves the cursor to the end of
                    text when system IME composition ends
           Product: Wine
           Version: 8.8
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: imm32
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail]
   Regression SHA1: 8ae0c308233e61cfc01ef52886077960d6513d93
      Distribution: ---

When the user attempts to compose character while the cursor is in the middle
of the text box, Rich Edit moves the caret to the _end_ of the text before
inserting the the newly composed character(s), instead of keeping the current
cursor position.

Steps to reproduce:

1. Activate fcitx5 (Hangul).
2. Enter the following text: "ABCXYZ"
3. Move the cursor (caret) to the middle of the string: "ABC|XYZ"
4. Compose a character.

Expected behaviour:

The composed character should be inserted between "ABC" and "XYZ"

Actual behaviour:
The composed character is inserted after "XYZ" and the caret moves to the end
of the string.