I tried the patch.
The eww problem is solved, but the problem still there, when I enable
auto-fill-mode or column-number-mode.

Please look at this video file for a better understanding:
http://s13.picofile.com/d/8399189550/7eeb413f-0df7-4da6-9db1-1632c9fc749f/out.mkv
https://filebin.net/mzmjm74lp7wsxr8e
https://gofile.io/d/H8xk26


For example, if you type in the following sentence:
این نام است که می‌ماند


Then go back a few characters in the same line and type words randomly. You
will see that the letters in some words are displayed separately. I type a
few words at random, after the word این and before the word نام :‌

این فراموشی را به همه اینکه فرمت مراتب افتتاح گرامی گرایش سراسیمه نام است
که می‌ماند

This line should look like this:

http://s12.picofile.com/file/8399190550/correct.png

‌But if one of the auto-fill-mode or column-number-mode is enabled. it will
be displayed this way:

http://s13.picofile.com/file/8399190584/malformed.png