mjx-assistive-mml can have greater height than mjx-container in MathJax 4

Issue Summary

mjx-assistive-mml can have greater height than mjx-container in MathJax 4, which may yield a scrollbar.

Steps to Reproduce:

1. Bootup Windows 11
2. Open Chrome 110
3. Go to https://codepen.io/alexedgcomb/pen/yLxbLZm

Observed: Scrollbar shows

Expected: No scrollbar

Technical details:

• MathJax Version: 4.0.0-alpha.1
• Windows 11
• Chrome 110 and Edge 110

I am using the following MathJax configuration:

MathJax = {
  options: {
    menuOptions: {
      settings: {
        assistiveMml: true
      }
    }
  }
}

and loading MathJax via

<script src="https://cdn.jsdelivr.net/npm/mathjax-full@4.0.0-alpha.1/es5/mml-svg.min.js"></script>

Supporting information:

On Windows 11 + Chrome 110, the mjx-container tag has 66.48px height, whereas the mjx-assistive-mml tag has 81.69px.

mjx-assistive-mml also has a greater height on other OS/browser combos:

• Windows 11 + Edge 110 (yielding scrollbar)
• Windows 11 + Firefox 110 (no scrollbar)
• MacOS 13.2 + Firefox 110 (no scrollbar)
• MacOS 13.2 + Chrome 110 (no scrollbar)
• MacOS 13.2 + Safari 16.3 (no scrollbar)

Known workarounds:

• Remove <math>'s overflow="scroll"
• Or, set assistiveMml to false

I'm not sure if this is a bug, expected behavior, or what. But, I thought it worth reporting.