gh-132267: fix desynchronized cursor position and buffer mismatch after resize

[ImFeH2]

• Issue: New REPL: Text display corruption when resizing terminal with multi-line content #132267

[ImFeH2]

before

after

[feoh]

Hi! I tested this PR on my Mac, MacOS latest and it works great.

It also helped me find another Pyrepl bug.

[StanFromIreland]

This has conflicts now.

[feoh]

Hi. I think I found a bug with this PR. Tested on MacOS latest. I reproduced this in WezTerm and also Apple's Terminal.app.

In particular, if you type or paste a very long line into the terminal with this patch, leaving your cursor at the end, and then hit Ctrl/Cmd+/- a number of times to resize the text, you'll find the cursor in the middle of the line.

[ImFeH2]

Thanks @feoh for catching that bug!
I made a mistake there. The previous method wasn't working well because reflow is terminal application behavior, making it difficult to guess rearranged content at this level. Now I just clear the screen and redraw everything to prevent any leftover characters.
I've tested this in Windows Terminal with WSL and it handles content exceeding window height well.
Does this fix it? Open to suggestions.

[feoh]

@ImFeH2 Hi! I'm delighted I could help!

Went to re-test and for some reason I can't check out this PR:

╭─cpatti at rocinante in ~/src/personal/cpython on main✔ 25-05-20 - 16:40:49
╰─⠠⠵ gh pr checkout 132360                                              <region:us-east-1>
remote: Enumerating objects: 53, done.
remote: Counting objects: 100% (29/29), done.
remote: Compressing objects: 100% (10/10), done.
remote: Total 53 (delta 20), reused 19 (delta 19), pack-reused 24 (from 1)
Unpacking objects: 100% (53/53), 64.06 KiB | 1.56 MiB/s, done.
From github.com:python/cpython
 ! [rejected]                refs/pull/132360/head -> gh-132267  (non-fast-forward)
failed to run git: exit status 1

I'll try a fresh CPython checkout later from the hotel and see if that helps :)

[feoh]

Hi I'm very sorry to be the bearer of bad tidings but I'm seeing more issues with the fixed fix :\

[ImFeH2]

Hi @feoh, are you referring to screen flickering or another issue? My expectations for REPL behavior might differ from yours, so clarification would be helpful. Thanks!
Would you mind if I include you as a co-author in this PR?