[BUG] Quitting via /quit or ctrl+d sometimes leaves shell in broken state

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

This one has been hard to hunt down the exact cause for. Occasionally, when quitting a claude code session (via /quit, ctrl+d, ctrl+c) i end up in a state where ctrl-sequences output characters to the prompt and backspace no longer works. The shell becomes fixed with reset, but ideally a shell should not become unusable after claude code exits.

What Should Happen?

Shell is usable normally after claude code exits.

Error Messages/Logs

No error messages, Ctrl-U for example spits out
;5u7;5u7;5u7;5u7;5u7;5u7;5u77;5u7;5u7;

Steps to Reproduce

Happens intermittently when exiting sessions, and I'm not sure of the exact condition. Seems to not happen exiting from a fresh session.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.83

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

Terminal is alacritty, OS is NixOS