bug#47462: 27.1; Fatal error 11: Segmentation fault

[Eli Zaretskii]

> From: Al Haji-Ali <[hidden email]>
> Date: Mon, 29 Mar 2021 09:03:52 +0100
>
> Executing the following code (for example with `eval-last-sexp`) seg faults
> my Emacs 27.1 with `emacs -Q`
>
> (progn (defmacro watch-variable (symbol)
> `(add-variable-watcher
>   ,symbol
>   (lambda nil
>     (message "variable changed %S" ,symbol)
>     (backtrace))))
>        (watch-variable load-file-rep-suffixes))

Thanks, I added protection on master from this kind of invalid usage.
With Emacs 27, just don't do that.