\href and math mode

[remimorvan]

This pull request fixes the behaviour of the \href command while in math mode, and of math passed as an argument to \href.

• The LaTeX code $\href{#}{x = y}$ did not produce any link. The href attribute was present in the XML file, but not in the HTML. This is fixed by changing the pmml_maybe_resize subroutine in the postprocessor.
• The LaTeX code \item foo \href{#}{$x = y$} (inside an itemize environment) was producing a link, but a linebreak was present between foo and the link. This is fixed by changing the css.

[dginev]

Nice initiative, as this synchronizes with another effort. MathML Core is about to introduce a new use for <a> anchor elements inside MathML to hold links, in contrast to the MathML 3 use of the href attribute on MathML elements themselves. That is tracked in PR w3c/mathml-core#307

I think we should wait just a little for that change to land in MathML Core, then start emitting these <a> elements right away in LaTeXML. Bruce likely has his own thoughts on the ideal timeline, logging my own for now.

[dginev]

Btw, the CSS change seems unrelated, and is probably discussed better elsewhere.

[brucemiller]

Interesting; So, href already works for tokens (handled in stylizeContent), but not for mrow expressionsl perhaps patching pmml_maybe_resize is the right approach (it's already been abused to do frames & colors, so it's not just resizing after all).

But I don't get what the 2nd point is about. The XML and HTML do indeed get a newline between the "foo" and the math element, but that shouldn't cause a linebreak in the display unless there's some other line wrapping going on.

[brucemiller]

What is the purpose of this change?