pyrepl messed up terminal if a signal handler expects stdin

Bug report

Bug description:

This is related to #129614 but more straightforward and irrelevant to pdb. (pdb needs this to be fixed though)

Start REPL from a terminal and do

import signal
signal.signal(signal.SIGINT, lambda s, f: input("test"))
<Ctrl+C>

Your terminal is messed up and newline won't work anymore. (Not the Python repl which will exit due to some run time error, the terminal itself is messed up)

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-138617

首先在 Linux 上的 pyrepl REPL 中复现信号处理程序和输入序列，然后检查 Ctrl+C 和 stdin 附近的终端状态处理。查看链接的 PR #138617，了解已经在进行的工作。当处理程序调用 input() 后终端仍可使用并接受换行时，即表示完成。