Find and replace NG with Chinese(zh_CN) character replaces extra characters

Summary:

The Chinese(zh_CN) characters can not be replaced Correctly, English Ok. If "find&replace" run with only one character, it's ok; But, if run with 3 or more characters, it's NG. (I can replace only one Chinese(zh_CN) character)

Steps to reproduce:

• open Inkscape
• Input 6 Chinese(zh_CN) characters and 3 English words in one line, set the Chinese(zh_CN) characters with chinese Font(ie. noto sans cjk SC), set the 3 English words with English Font.
• open find&replace(ctrl+F)
• input 3 Chinese(zh_CN) characters in the "find" input box.
• input "666" in the "replace" input box.
• click the "Find" button.It will tips "1 object found".
• click the "Replace All" button.

What happened?

All the 6 Chinese(zh_CN) characters were replaced with "666", not the 3 characters entered before.

What should have happened?

Only the 3 characters entered before were replaced.

Sample attachments:

Version Info:

- Inkscape Version: 1.0(4035a4fb49, 2020-05-01)
- Operating System: Debian Stretch
- Operating System version: Debian Stretch 9.12 / Gnome