[4.3.0] CJK (multi-byte character) input issues using the List, Quote, Pullquote block with Firefox and Chrome

[inc2734]

Describe the bug
When Japanese is entered in the list block, conversion is decided automatically.
I also reproduced custom blocks set to multiline="li".

To Reproduce
Steps to reproduce the behavior:

1. Insert list block
2. Enter multi-byte characters
3. See error

Screenshots

on https://wordpress.org/gutenberg/

Desktop (please complete the following information):

• OS: macOS High Sierra
• Browser Chrome
• Version 70.0.3538.77

It also reproduced in Firefox, but it worked correctly in Safari.

Additional context
I use Gutenberg v4.3.
This problem does not occur in v4.2.

[shinyabw]

I tested with WordPress 4.9.8 and Gutenberg 4.3.0 and can confirm that Japanese text (double-byte character) is not usable (cannot type properly) in the list block. I also found the same issue exists with the quote and pullquote blocks.

[lqdjp]

I also found the same issue in the cover and button block.

[mongonta0716]

I also found the same issue.
Problems also occur in Google Chrome(70.0.3538.102) on Windows10 Pro 64bit(build 17134.345).
It also reproduces in Firefox(63.0.1).

It worked correctry in Microsoft Edge(42.17134.1.0).

[shinyabw]

@mongonta0716 Thank you. I tested further. I am using Mac OS 10.13.6. The issue exsists with Firefox 63.0.1 and Chrome 70.0.3538.102 (Official Build), but it worked fine on Safari 12.0.1.

@lqdjp I could not confirm the issue is the cover and button blocks.

[torounit]

Using <RichText multiline> will cause this problem.

[shinyabw]

@lqdjp I wonder if you are testing this issue on WordPress 5.0-beta4-43896.

[lqdjp]

@shinyabw Yes, I tested with WordPress 5.0-beta4-43896.