hyperref in HTML5 produces invalid internal links

[eudoxos]

I am hitting a bug where the HTML5 renderer render \hyperref[label]{text} incorrectly (producing #. anchor):

plastex/plasTeX/Renderers/HTML5/hyperref.jinja2s

Lines 18 to 19 in aa5de5c

	name: hyperref
	<a href="{{ obj.attributes.url }}#{{ obj.attributes.category }}.{{ obj.attributes.name}}" >{{ obj }}</a>

This is trivially reproducible with

\documentclass{article}
\usepackage{hyperref}
\begin{document}
    Reference to \hyprref[foo]{the next section}
    \section{foo}\label{foo}
\end{document}

I get something functional if I copy the definition of ref from

plastex/plasTeX/Renderers/HTML5/Crossref.jinja2s

Lines 1 to 2 in 02610ee

	name: ref
	{% if 'label' in obj.idref and obj.idref.label.ref %}<a href="{{obj.idref.label.url}}">{{obj.idref.label.ref}}</a>{% else %}??{% endif %}

just replacing {{obj.idref.label.ref}} with {{ obj }}. Please apply that after reviewing, I am not much sure if this is correct.

(As a note, I found out that \label is always bound to the last section heading (unlike in LaTeX, where it can be positioned anywhere), and that \hypertarget does not suffer from that... Just saying, perhaps this observation is useful for someone later.)