Exporting to HTML, LaTeX header is not recovered in the Org buffer

["Mosè Giordano" <giordano.mose@libero.it>]

Hi folks,

in order to export to HTML LaTeX fragments (not necessarily math
fragments) as PNG pictures, I set
--8<---------------cut here---------------start------------->8---
#+LATEX_HEADER: \newenvironment{dummy}{}{}
#+OPTIONS: tex:dvipng
--8<---------------cut here---------------end--------------->8---
and insert LaTeX fragments in `dummy' environments.  This is useful
for showing the aspect of a LaTeX fragment without compiling,
cropping, and converting to PNG an external LaTeX file.  Are there
better ways to do that?

For example
--8<---------------cut here---------------start------------->8---
#+TITLE: foo
#+LATEX_HEADER: \usepackage{lipsum} \newenvironment{dummy}{}{}
#+OPTIONS: tex:dvipng

\begin{dummy}
\lipsum[1]
\end{dummy}
--8<---------------cut here---------------end--------------->8---
used to work until Org < 8 (of course with `LaTeX:dvipng' instead of
`tex:dvipng'), but with the new HTML exporter the LaTeX header is
recovered inside the `org-create-formula-image-with-dvipng' function
while being in the ` *temp*' buffer, so the LATEX_HEADER option set in
the Org file is discarded.  Is it an intended behavior?  Or is it a
bug?  I'm running Org 8.2.3c (20131125) from Elpa.

Thank you,
bye,
Mosè

P.S.: please keep me in CC, I'm not subscribed to the list.