Bug: org-toggle-latex-fragment doesn't work as documented [9.2.1 (release_9.2.1-60-gb0379f @ /home/carlos/local/stow/emacs/share/emacs/site-lisp/org/)]

[Carlos Pita <carlosjosepita@gmail.com>]

According to the docstring:

```
(defun org-toggle-latex-fragment (&optional arg)
  "Preview the LaTeX fragment at point, or all locally or globally.

If the cursor is on a LaTeX fragment, create the image and overlay
it over the source code, if there is none.  Remove it otherwise.
**If there is no fragment at point, display all fragments in the
current section**.
```

Notice the last sentence. Nevertheless C-c C-x C-l acts like a toggle
that will remove all previews as far as there is at least one preview
active, that is a toggle with a preference to UNdisplay all fragments in
the current section. Now, there is C-u C-u C-c C-x C-l for that. AFAICS,
the current situation is such that there is no way to get a full preview
of an entire section when at least one formula is already previewed,
except for unpreviewing and repreviewing everything. This is not only
inconvenient but also contradicts the docstring and mostly overlaps the
C-u C-u case.

I suggest to make C-c C-x C-l a toggle with preference for previewing,
that is: preview everything except when everything is already previewed.


Regards
--
Carlos

---

Emacs  : GNU Emacs 26.1.91 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2019-02-10
Package: Org mode version 9.2.1 (release_9.2.1-60-gb0379f @ /home/carlos/local/stow/emacs/share/emacs/site-lisp/org/)