bug#2370: 23.0.90; decode-coding-region make emacs crash

[Kenichi Handa]

In article <87d4dfqg5h.fsf@cyd.mit.edu>, Chong Yidong <cyd@stupidchicken.com> 
writes:

> Kenichi Handa <handa@m17n.org> writes:
> > I found two bugs related to this problem, and just installed
> > a fix for one of them.  Now the above specific problem
> > should be fixed.  I'll keep on workning to fix the other bug
> > to make the decoding more robust.

> Thanks.  I think decode_coding should also verify the size of the
> unprocessed bytes before writing them to coding->carrover.  This way,
> future bugs of this sort will not cause memory corruption (which might
> be a security concern).  What's your opinion?

Yes.  I'm going to add such a check.

But it doesn't solve the underlying problem of handling too
long (and wrong) composition sequence in iso-2022 decoding.
Solving it requires a little bit more time.

---
Kenichi Handa
handa@m17n.org