Define what the content box is for MathML token elements

[bfgeek]

Currently the implementations differ here, a very simple test case.
https://www.software.hixie.ch/utilities/js/live-dom-viewer/?saved=6689

I'm not sure what is correct here. However what ever is decided needs a bunch of tests to ensure interoperability.

[fred-wang]

mi and mtext are MathML token elements. Do you mean content box for any MathML element?

issue w3c/mathml#14 might be involved here

[bfgeek]

No - see test case. I think this relates to how the ascender/descender contributes to the block-size of token elements.

[dani31415]

My 5 cents to clarify the issue. On Firefox, the issue gets more clear when comparing an <mi> and a <span> side by side with an outline around it (no margin, no border and no padding):

The red one is the <mi> and the blue is the <span>.

I created an example with mathvariant="normal" (to make the comparison fair).
https://www.software.hixie.ch/utilities/js/live-dom-viewer/?saved=6783

[fred-wang]

The core spec defines what the content box for token elements should be, basically deferring to block layout: https://mathml-refresh.github.io/mathml-core/#text-mtext