committed to tl, closing. thanks to all.

I found that -- get changed to NAK (hex 15) in HTML when compiling in lualatex mode. This is a big problem. It means I can't use all the code formating code I have. Below is a MWE, and more screen shots and information can be found at this link

http://tex.stackexchange.com/questions/317293/tex4ht-corrupts-inside-cdata-in-the-html-file

\documentclass[11pt]{article}%
\IfFileExists{luatex85.sty}{\usepackage{luatex85}}{}

\ifdefined\HCode% detect tex4ht
\usepackage[utf8]{luainputenc}
\usepackage[T1]{fontenc}
\else
\usepackage{fontspec}
\fi

\begin{document}
\ifdefined\HCode
{\ScriptEnv{html}{\ifvmode\IgnorePar\fi\EndP\NoFonts\hfill\break}{\EndNoFonts\endgraf}
\begin{html}
<PRE>
-- this is a test
</PRE>
\end{html}}
\else
test
\fi

\end{document}

Now compiling the above using make4ht --lua foo.tex and looking at the HTML, we see that the -- has been changed to HEX 15.

When compiling using make4ht foo.tex, the problem do not exist and -- are left as is.

I am using TL 2016 on Linux