Re: [Pre-PATCH] Overhaul of the LaTeX preview system

[Matt Huszagh <huszaghmatt@gmail.com>]

Hi Timothy,

Thanks for your work on this.

I've run into an issue related to the change you made in
209e5f5f4047a34db27c3b5dff4077bb1da9ceed that makes org-latex-compile
asynchronous.

This breaks the org-babel-latex-pdf-svg-process functionality I
introduced in commit ae35a345903c640397a8d29812112d72a9f8494a.

To reproduce the issue, you can create an org file with the following
single latex source block:

#+header: :file "out.svg"
#+begin_src latex :hidden
\begin{equation}\tag{1.6.3.1}
  \mathbf{F} = q \mathbf{E},
\end{equation}
#+end_src

If you execute this with C-c C-c, it complains about the PDF file not
being present. The problem can be found starting in line 182 of
ob-latex.el of your current (as of this writing) feature branch commit
8384289762b41b26e75d2e80c37ec84bcc552d32. The issue is that
org-babel-latex-tex-to-pdf (which delegates to org-latex-compile)
creates the PDF after org-compile-file (in line 185) tries to generate
an SVG file from it. In fact, I was initially confused because I
couldn't reproduce the issue with edebug (obviously, because that gave a
long enough delay for the file to be created before attempting the svg
creation).

org-latex-compile seems like it could be a dangerous function to change
to be asynchronous, as it's used in a lot of places and its very
possible that other people (like myself) were relying on it being
synchronous when they made some change that used it. I haven't looked at
its other invocations, but I wouldn't be surprised if this breaks other
things too. I hesitate to suggest alternatives because I don't know
enough about your use case. But, maybe you could achieve what you want
through a new org-latex-compile-async function, or add a nondefault
option to org-latex-compile?

Matt