Hi,

AUCTeX has taken back this change, realizing that texmathp.el is also used
in contexts where the mechanisms of AUCTeX to find out about LaTeX packages
being used does not work.  I do think this is already fixed in the latest
AUCTeX version.  At least it is fixed in their git.

- Carsten

Carsten

On Fri, Aug 28, 2020 at 7:09 AM Kyle Meyer <kyle@kyleam.com> wrote:

> Stefi writes:
>
> > It might be a change to texmathp.el. It is part of Auctex and checks if
> > math mode is on or off. I could not find align environment in the list
> > of default environments. Maybe that has changed.
> >
> > However, I added align and align* to "Texmathp Tex Commands" from the
> > customize browser (open a .tex file to customize auctex). Tab-expansion
> > is working now. Can anyone confirm?
> >
> > In my .emacs, it added to custom-set-variables:
> > '(texmathp-tex-commands (quote (("align*" env-on) ("align" env-on))))
>
> Yes, that results in expansion on my end as well.
>
> It looks like this issue was introduced with AUCTeX's 91701704 (Delete
> overhead in extending font lock range of math expression, 2020-06-11).
> If you're getting AUCTeX from ELPA, the regression is included the
> current version there (12.2.4, 2020-06-29).
>
> At the start of this month, it was fixed in f04a508f (Restore all math
> environments in texmathp.el, 2020-08-01), so the issue should go away
> with the next update that lands on ELPA.
>
>