Request: Ctrl+C bugfix to be ported from cygwin

[aont]

Ctrl+C is sometimes ignored under pseudo console

Describe the issue

Ctrl+C is sometimes ignored under pseudo console
This happens with bash and python (msys2 version).
Ash does not reproduce this issue.
Python of mingw version does not reproduce this issue.

Bash of Cygwin vesion does also reproduce this issue.

Steps to Reproduce the Problem 1

1. Open msys2 under Windows Terminal following the instructions here: https://www.msys2.org/docs/terminals/
2. Hold down ctrl key and press 'C' down and up many times.

Steps to Reproduce the Problem 2

I also made another simple conpty environment.
EchoCon.cpp from https://gist.github.com/aont/0d40aab4ddd332d4da4d8e84cf625c6e

1. Compile EchoCon.cpp (with MSVC) and execute under cmd.exe
2. Hold down ctrl key and press 'C' down and up many times.

Extra Information

I suspected termios has some bug. So I made a simple termios program to catch ctrl - c.
However, it works fine.
getkey.cpp from https://gist.github.com/aont/0d40aab4ddd332d4da4d8e84cf625c6e

Additional Context: Operating System, Screenshots

• OS: Windows 10 Pro 19043.1237
• msys2-runtime 3.2.0-15
• bash 5.1.008-1
• python 3.9.6-1

[aont]

I dug into this issue and found readline is related to this issue.
I made a simple program that reproduces this issue.
rltest.cpp from https://gist.github.com/aont/0d40aab4ddd332d4da4d8e84cf625c6e

I will sent bug report of this issue to readline mailing list.

[aont]

After all, this issue is originated from cygwin runtime.

I submitted a bug report to cygwin mailing list.
https://cygwin.com/pipermail/cygwin/2021-November/249749.html

Now cygwin runtime is fixed.
cygwin/cygwin@561767f
cygwin/cygwin@2221beb
cygwin/cygwin@eb628ca
I request these patches to be ported to msys2.

Since this issue is originated from msys2 runtime, I close this issue here and submit new issue on msys2-runtime.
msys2/msys2-runtime#68