Message loops infinitely when editing and resending a prompt

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?

When I copy an existing message, edit it, and resend it, the message gets submitted in an infinite loop — the same message appears repeatedly in the chat without stopping.

What Should Happen?

Message sends once and stops.

Error Messages/Logs

Steps to Reproduce

Send a message in Claude Code
Copy that message text
Paste it into the input, make edits
Send the edited message
Message submits repeatedly in a loop without stopping

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.25

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

OS: Windows 11 Home (10.0.26200)
Shell: bash via Claude Code CLI

<img width="2158" height="1609" alt="Image" src="https://github.com/user-attachments/assets/cf8a09de-1e25-4aef-883c-c87528413ad6" />