[O] org-preview-latex-fragment does not include #+LaTeX_CLASS definition

[Michael Bach]

Hello everyone,

org-mode version 7.8.02

When doing `org-preview-latex-fragment' on a buffer with custom set
#+LaTeX_CLASS and some #+LATEX_HEADER lines, the pdflatex process to
create the ltxpng/*.png images fails e.g. with:

Failed to create dvi file from /tmp/orgtex1650tNa.tex

Now when I check the temporary .tex file under
e.g. /tmp/orgtex1650tNa.tex, I see that the #+LATEX_HEADER: parts of my
file got put in, but the preamble does not include the #+LaTeX_CLASS
\usepackage definitions.

The #+LATEX_HEADER lines depend on the packages loaded in my
#+LaTeX_CLASS definition, so there is no wonder pdflatex fails.

My actual question: Why is the tmp tex file generated without the custom
#+LaTeX_CLASS preamble?

Best Regards,
Michael