[Bug] Settings watcher drops file after atomic swap with unreadable file, applies empty settings

Bug Description
The settings watcher permanently drops ~/.claude/settings.json after the file is briefly swapped for an unreadable one; the session then runs with empty user settings until restart. Versions: 2.1.285 and 2.1.286, macOS, native install. Repro, with a throwaway CLAUDE_CONFIG_DIR whose settings.json has a statusLine and some permissions.allow rules: 1. Start claude --debug and wait for the status line. 2. cp -p settings.json settings.new.json, then chmod 000 settings.new.json, then mv -f settings.new.json settings.json 3. Wait 5 s, then chmod 600 settings.json Expected: on EACCES, keep the last good user settings, and reload once the file is readable again. Actual: - The debug log shows settings file read failed ... EACCES: permission denied, then Replacing all allow rules for destination 'userSettings' with 0 rule(s), then two more EACCES retries 2 s apart. - After that, Detected change to ...settings.json never appears again. The chmod 600, a later touch and later content edits are all missed. - The status line disappears, and user allow rules, hooks and env are gone until restart. - An in-place chmod 000 → chmod 600 on the same file recovers fine. Only swapping in a new unreadable file triggers this. Likely cause: - The chokidar settings watcher (atomic: true, ignorePermissionErrors: true) fails to re-watch the new file and silently drops it. - A file that can't be read is applied as empty settings instead of keeping the previous ones. Real-world trigger: configuration-management tools that rewrite settings.json as root and then fix ownership. Possibly related, not reproduced in isolation: after the same event, sessions on ≤2.1.285 sometimes stop repainting entirely (blank screen, but typing still reaches the session).

Environment Info

• Platform: darwin
• Terminal: intellij
• Version: 2.1.286
• Feedback ID: a0f952a1-0605-4b2c-949a-4f9ebae7640d

Errors

[]