Poetry shell - Problem when erasing accented letters

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• Archlinux, 5.9.3-arch1-1
• Poetry 1.1.4
• termite v15
• zsh 5.8
• No dependencies whatsoever

Issue

Hi,

I create this very simple test script:

print("Enter something: ", end="")
text = input()
print(text)

When I run it from my normal shell (zsh 5.8) I can type "ééé", and then erase those three characters, end of the story.

When I run it from inside poetry shell, I can type "ééé", and then I can erase all the way to the "g" at the end of something, including it. So I can "erode" the prompt, so it looks like "Enter somethin". If I now type something, with or without accents, it will be written right after "somethin", and it will be correctly registered and printed to me. So I can read "Enter somethinhello", hit Enter, and "hello" gets printed on the next line.

The number of prompt characters I can erase depends on the number of accented letters I've entered first. If I enter four of them, such as "éééé", I can erase one character further, until it reads "Enter somethi".

Start by running the provided Python input script inside poetry shell under zsh, then compare backspace behavior with the normal shell. Trace the shell's handling of accented input and terminal editing; done means accented characters can be erased without eroding the prompt or changing where subsequent input appears.