[BUG] Claude Desktop strips newlines when pasting from MacVim

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 pasting text copied from MacVim, Claude desktop strips newlines, collapsing the text into a single line.

What Should Happen?

Newlines are preserved, matching the original text from MacVim.

Error Messages/Logs

Steps to Reproduce

1. Copy text containing newlines from MacVim (e.g., using "+y or the system clipboard)
2. Paste into the Claude desktop input field

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.92 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

Additional Context
Pasting the same text from MacVim into Apple Notes preserves newlines correctly, which suggests the issue is in how Claude desktop processes the clipboard content rather than how MacVim writes to the clipboard.

Environment

• OS: macOS 26.4.1
• Claude desktop version: Claude 1.2773.0 (884b37) 2026-04-15T14:32:09.000Z
• Source application: MacVim