Regression with mglyph

[NSoiffer]

Here's the code:

<math  xmlns="http://www.w3.org/1998/Math/MathML">
    <mi>
         <mglyph fontfamily="my-braid-font" index="2" alt="23braid"/>
    </mi>
    <mspace width="10px"/>
    <mn>
         <mglyph fontfamily="Curlz MT" index="65" alt="script 'A'"/>
    </mn>
    <mspace width="10px"/>
    <mn>
         <mglyph fontfamily="Arial" index="97" alt="lowercase 'a'"/>
    </mn>
</math>

Here's V2's rendering:

Here's V3's rendering:

[dpvc]

The current mglyph implementation is somewhat more restricted than the v2 version. It doesn't currently implement the deprecated fontfamily and index attributes (and may not in the future). Actually, it does fontfamily as that was available on all elements, but it doesn't do the index attribute. So you are getting broken image icons for the missing src attribute, and the content of the alt attributes since the images aren't showing.

I'll look into implementing the index attribute for the future.

[dpvc]

I'm transferring this issue to the main MathJax issue tracker, so it is easier to locate.