[BUG] Output text hard-wraps at 80 columns when $COLUMNS is not set (Terminology terminal)

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?

Claude Code wraps all text output at 80 columns regardless of actual terminal
width. The issue appears when $COLUMNS is not exported by the terminal
emulator (Terminology on Linux). tput cols correctly returns the terminal
width, but Claude Code does not use it as a fallback.

What Should Happen?

Output should wrap at the actual terminal width, using tput cols or ioctl
TIOCGWINSZ as a fallback when $COLUMNS is unset.
Environment

• Claude Code version: 2.1.84
• OS: Ubuntu 24.04 / Linux 6.14.0-37-generic x86_64
• Terminal: Terminology
• $TERM: xterm-256color
• $COLUMNS: (unset)
• tput cols: 80 (but terminal is wider than 80)

Error Messages/Logs

Steps to Reproduce

To reproduce

1. Open Terminology (or any terminal that does not export $COLUMNS)
2. Run claude
3. Observe that all text output wraps at 80 columns even if the terminal is

wider

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.84

Platform

Anthropic API

Operating System

linux

Terminal/Shell

Other

Additional Information

overlapped text