[BUG] output duplicates when terminal is resized vertically

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?

Description:
When the terminal window is resized vertically (increasing height) while Claude Code is running, previously rendered output duplicates on screen. The content appears twice in the visible area.
Actual behavior:
Output is duplicated visually when the terminal height is increased.

What Should Happen?

Expected behavior:
Output remains stable and renders once regardless of terminal size changes.

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

1. Start a Claude Code session
2. Run any prompt that produces a multi-line response
3. While the response is displayed, drag the terminal window to increase its vertical height
4. Observe that the output is duplicated in the newly expanded area

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

• Claude Code version: 2.1.136

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_