From: Peter Stephenson <p.w.stephenson@ntlworld.com>
To: zsh-workers@zsh.org
Subject: Re: PATCH: Don't crash when math recursion limit is exceeded
Date: Sun, 10 Mar 2013 18:42:44 +0000 [thread overview]
Message-ID: <20130310184244.41e1d554@pws-pc.ntlworld.com> (raw)
In-Reply-To: <1362917197-2576-1-git-send-email-mikachu@gmail.com>
On Sun, 10 Mar 2013 13:06:37 +0100
Mikael Magnusson <mikachu@gmail.com> wrote:
> This used to never trigger for me when compiling in debug mode, but I
> finally had better luck today and tracked it down.
>
> *ep seems to already be NULL, but I couldn't quite figure out where it
> was set to NULL so I figured it can't hurt to make it explicitly NULL
> at that point. I suppose setting *ep = ""; would also work (without the
> second hunk)?
Another way of doing it would probably be to set "*ep = s", which is
consistent with what *ep is supposed to be doing.
If you set it to NULL it's probably safest to change the value returned
by the other calls of mathevall() around line 960 pre-patch, which also
outputs the "bad math expression" error. I don't see why they shouldn't
be fully consistent; zerr() already tests for errflag, so they shouldn't
need to test for that, but either neither or both should.
--
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/
> ---
> Src/math.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/Src/math.c b/Src/math.c
> index f8a4eef..43cede9 100644
> --- a/Src/math.c
> +++ b/Src/math.c
> @@ -362,6 +362,7 @@ mathevall(char *s, enum prec_type prec_tp, char **ep)
> if (mlevel >= MAX_MLEVEL) {
> xyyval.type = MN_INTEGER;
> xyyval.u.l = 0;
> + *ep = NULL;
>
> zerr("math recursion limit exceeded");
>
> @@ -1352,7 +1353,7 @@ matheval(char *s)
> }
> x = mathevall(s, MPREC_TOP, &junk);
> mtok = xmtok;
> - if (*junk)
> + if (junk && *junk)
> zerr("bad math expression: illegal character: %c", *junk);
> return x;
> }
> --
> 1.7.10.GIT
next prev parent reply other threads:[~2013-03-10 19:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-10 12:06 Mikael Magnusson
2013-03-10 18:42 ` Peter Stephenson [this message]
2013-03-10 20:01 ` Mikael Magnusson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130310184244.41e1d554@pws-pc.ntlworld.com \
--to=p.w.stephenson@ntlworld.com \
--cc=zsh-workers@zsh.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/zsh/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).