IntersectionObserver triggers unexpected editor resets

Phenomenon

In Safari, if an IntersectionObserver is watching an editor div, and that div’s intersection ratio changes (even slightly during scrolling or keyboard expansion), the browser may trigger a re-render cycle that clears the current IME composition.

Reproduction Steps

1. Attach an IntersectionObserver to the editor.
2. Start an IME composition (e.g., Korean or Japanese).
3. Scroll the page so the editor’s position moves slightly.
4. Observe that the current underlined text is immediately committed or deleted.

Observed Behavior

Safari’s “Is visible” check for event dispatching is sensitive to observer cycles, leading to premature compositionend events.