bug#47456: 27.1; emacs hangs using aspell in auctex

[Eli Zaretskii]

> Date: Sun, 28 Mar 2021 21:57:06 +0000
> Accept-Language: da-DK, en-US
> From:  Brian Elmegaard via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> In Emacs 27.1 on Windows with auctex 13.0.4, I have installed aspell as 
> described in
> https://emacs.stackexchange.com/a/45752 and it works, except
> in .tex files.
>  
> When I M-x ispell-buffer emacs hangs after a few moments and it doesn't
> become active before I press C-g and skips the spelling.
> The same happens for flyspell.
>  
> It seems to work if line 4084 of ispell.el is commented:
>       ;;     (ispell-send-string "+\n")    ; set ispell mode to tex 

It doesn't hang here with Hunspell.

Does the above work if you invoke Aspell from the cmd prompt?  IOW,
how do we know the problem isn't in the port of Aspell you are using?
The fact that C-g interrupts the hang could mean that Emacs waits for
Aspell.