Eli Zaretskii <eliz@gnu.org> writes:

>> What solution did you have in mind?
>
> Something like this:
>
>   FOR_EACH_TAIL (tail)
>     {
>       Lisp_Object car = XCAR (tail);
>       if (CONSP (car)
> 	  && (NILP (testfn)
> 	      ? (EQ (XCAR (car), key) || !NILP (Fequal (XCAR (car), key)))
> 	      : !NILP (call2 (testfn, XCAR (car), key))))
> 	return car;
>     }

Thanks, it's indeed much better.