[O] Equation references in HTML export

[Thibault Marin]

0001-ox-html.el-Add-MathJax-label-and-reference-to-equati.patch
Description: Text Data

Hi list,

I am trying to get links to equations to work with HTML export (with Org mode
version 9.1.6 (release_9.1.6-295-ge8cd52 @ /.../org-mode-git/lisp/)).

It currently does not seem to work, as demonstrated by the following example org
file:

#+begin_src org
,#+NAME: eq-test
\begin{align}
1 + 1 = 0
\end{align}

link to equation [[eq-test]]
#+end_src

The relevant part of the resulting HTML is:

#+begin_src html
\begin{align}
1 + 1 = 0
\end{align}

<p>
link to equation <a href="#org0b47727">1</a>
</p>
#+end_src

The =align= block does not have a =label=.  The link could use =\ref= (or
=\eqref=) which is handled by MathJax.  The attached patch attempts to fix
this.  It produces the following (correct?) output:

#+begin_src html
\begin{align}
\label{eq:orgbfedefe}
1 + 1 = 0
\end{align}

<p>
link to equation \eqref{eq:orgbfedefe}
</p>
#+end_src

The patch attempts to re-use functionality from ox-latex.el to avoid code
duplication.  Please let me know if there is a better way to achieve the
same result.

Does this look like something that could eventually be merged?  Let me know if
any change is required.

Thanks,

thibault