IDE diagnostics attachments are validated before replay / Claude Code v2.1.223

You'll notice

Useful2 Signal0

Elsewhere

Editor diagnostics restored from saved sessions are checked for junk before being shown, so bad data can't garble your screen.

What

Diagnostics restored from a replayed attachment are now sanitized, so a malformed or crafted payload cannot reach the renderer.

Details

a new sanitizeDiagnosticFiles static drops non-array payloads and logs once per payload shape
file entries are dropped unless they have a string uri and an array of diagnostics; individual diagnostics are dropped unless they have a string message and numeric range start line and character
missing ranges are normalized, and the count of dropped files and diagnostics is logged once per payload
severity strings map through an explicit table (error, warning, info, information, hint), and getSeveritySymbol now uses Object.hasOwn and rejects non-string input, so a crafted severity cannot reach an inherited property

Evidence

Dropped a ${o} diagnostics files payload from a replayed attachment, diagnostics files payload from a replayed attachment

Strings lifted out of the shipped bundle, so the claim above can be checked against them.