Subject: Re: bug#24118: 25.1; [PATCH] Fix a possible crash caused by mapcar1

From: Andreas Schwab <[email-masked]>
Date: Sun, 31 Jul 2016 15:18:09 +0200

Chris Feng <[email-masked]> writes:

> diff --git a/src/fns.c b/src/fns.c
> index d5a1f74..1804bce 100644
> --- a/src/fns.c
> +++ b/src/fns.c
> @@ -2524,6 +2524,10 @@ mapcar1 (EMACS_INT leni, Lisp_Object *vals, Lisp_Object fn, Lisp_Object seq)
>  	    vals[i] = dummy;
>  	  tail = XCDR (tail);
>  	}
> +
> +      /* In case the list was tampered and the loop terminated early. */
> +      if (i < leni)
> +        memclear (vals + i, (leni - i) * word_size);

That should not depend on the representation of Qnil.

Andreas.

-- 
Andreas Schwab, [email-masked]
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."