Cursor is placed at start of uncommitted string while composing

[birtles]

Do you want to request a feature or report a bug?

Report a bug.

What's the current behavior?

1. Navigate to https://www.slatejs.org/#/plain-text
2. Focus the text box
3. Activate an IME
4. Type some text
5. Notice that the cursor is placed at the start of the string being composed.

Occurs on Windows with Microsoft IME in Chrome 68 and Firefox 63. (I thought I could reproduce in Edge but now it appears to be working correctly in Edge. Odd.)

Firefox:

Chrome:

What's the expected behavior?

The cursor is placed at the end of the string being composed.

cf. Draft JS (shown in Firefox below):

[thesunny]

Note: Working on this in this issue #2062

[ianstormtaylor]

Closing in favor of #2368, if you think this is unrelated let me know and we can reconsider.