[issue40100] Unexpected behavior when handling emoji under codec cp936

[Alex]

New submission from Alex <2423067593 at qq.com>:

Python 3.8.2 IDLE has an unexpected behavior.
When I insert an emoji into IDLE like '😍'.
Then I found I can't delete it(by typing backspace).
When I type the left arrow then it became '��'(U+FFFD).
Then I type the left arrow again, then it is '😍' again!
(When I use the delete button, or type the right button there aren't any bugs.)
What's wrong?
Also, when I have two emojis like '🙏🙏', I press delete button between them, nothing happens; when I delete on the right, both of them disappear!
(This bug seems not appears on plain 0.)

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assignee: terry.reedy
components: IDLE
messages: 365247
nosy: Alex-Python-Programmer, terry.reedy
priority: normal
severity: normal
status: open
title: Unexpected behavior when handling emoji under codec cp936
type: behavior
versions: Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue40100>
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