CodeMirror: Text disappears when candidate is confirmed in IME composition

[wildworks]

In input modes with IME compositions, such as Japanese, the text disappears when a candidate is confirmed. This occurs when it is in a bracket and indented.

For example, enter "あああ" as follows:

.test {
        あああ
}

Then press Enter to confirm your entry and the text will disappear:

.test {
        
}

Perhaps this problem is similar to one that has occurred in the past with the Gutenberg project. I believe that the Enter key to confirm a character is being detected incorrectly, causing unintended behavior.

• ​https://github.com/WordPress/gutenberg/pull/45607
• ​https://github.com/WordPress/gutenberg/pull/45510

The IME composition is described in detail in the following tracking issue.

​https://github.com/WordPress/gutenberg/issues/45605

[wildworks]

I did a little more research and found that text entered in IME mode disappears if it is immediately after a tab indent.
For space indentation, the problem doesn't occur.

You can see this in the attached japanese-input-disappears-after-tab-indentation..mp4.

[wildworks]

Perhaps it is a problem with CodeMirror itself. I have submitted an issue.
​https://github.com/codemirror/codemirror5/issues/7012