Event.clone() bypasses validation

[thedhanawada]

Problem

When you clone an event with updates using event.clone({ start: badValue }), the updates skip validation. This means you can create events with invalid data.

File: core/events/Event.js

What happens

const event = new Event({ title: 'Meeting', start: new Date() });
const cloned = event.clone({ start: 'not-a-date' }); // No error, bad data gets through

How to fix

Run the updates through normalizeEventData() before merging:

clone(updates = {}) {
  const normalizedUpdates = updates ? Event.normalizeEventData(updates) : {};
  return new Event({
    ...this.toJSON(),
    ...normalizedUpdates,
    id: undefined
  });
}

This ensures all updates are validated just like when creating a new event.