[BUG] claude --resume crashes with null is not an object (evaluating 'A.split')

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?

Error Message

ERROR  null is not an object (evaluating 'A.split')
/$bunfs/root/claude:2725:1261

Stack trace points to VkB function:

- VkB (/$bunfs/root/claude:2725:1261)
- D2B (/$bunfs/root/claude:2355:4368)

Root Cause

In the VkB renderer (/$bunfs/root/claude:2725), the originalFile parameter A is null, but the code calls A.split('\n') without a null check:

VkB({ filePath: T, structuredPatch: R, originalFile: A }, _, { style: B, verbose: D }) {
    return m4.createElement(HyR, {
        firstLine: A.split('\n')[0] ?? null,  // ← crashes when A is null
        fileContent: A,
        ...
    })
}

Triggering Input

The crash is triggered when resuming a session that contains a file-history-snapshot entry where a tracked file's backupFileName is null:

{
  "type": "file-history-snapshot",
  "snapshot": {
    "trackedFileBackups": {
      "src/agents/autopilot_manager.py": {
        "backupFileName": null,
        "version": 1,
        "backupTime": "2026-04-14T08:10:25.445Z"
      }
    }
  }
}

This happens for newly created files that have not yet been backed up (version 1, no prior backup). When --resume renders the diff for this file, originalFile is null because there is no backup to read from, and the renderer does not handle this case.

What Should Happen?

Triggering Input

The crash is triggered when resuming a session that contains a file-history-snapshot entry where a tracked file's backupFileName is null:

{
  "type": "file-history-snapshot",
  "snapshot": {
    "trackedFileBackups": {
      "src/agents/autopilot_manager.py": {
        "backupFileName": null,
        "version": 1,
        "backupTime": "2026-04-14T08:10:25.445Z"
      }
    }
  }
}

This happens for newly created files that have not yet been backed up (version 1, no prior backup). When --resume renders the diff for this file, originalFile is null because there is no backup to read from, and the renderer does not handle this case.

Error Messages/Logs

### Error Message

ERROR  null is not an object (evaluating 'A.split')
/$bunfs/root/claude:2725:1261


Stack trace points to `VkB` function:

- VkB (/$bunfs/root/claude:2725:1261)
- D2B (/$bunfs/root/claude:2355:4368)

Steps to Reproduce

Steps to Reproduce

1. Start a Claude Code session in a project
2. Have Claude create a brand-new file (never existed before) — this produces a file-history-snapshot entry with backupFileName: null
3. Exit the session
4. Run claude --resume <session-id>
5. → Crash immediately

Expected Behavior

originalFile being null should be handled gracefully, e.g.:

firstLine: A?.split('\n')[0] ?? null

Environment

• Claude Code version: 2.1.63
• Installed via: Homebrew
• OS: macOS

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.63

Platform

Other

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_