Re: xconq/8: Rule called "replace".

[Erik Sigra <sigra at home dot se>]

Thursday 07 August 2003 01.47 skrev Eric McDonald:
> On Wed, 6 Aug 2003, Erik Sigra wrote:
> > * Make sure that the name is not too long for the buffer. (But does the
> > rest of xconq always check such things?)
>
> No. But, my personal opinion is that these things should be checked for,
> even if it means either truncating strings or dynamically allocating
> memory to accomodate them. Xconq is quite admirable in that it tries to do
> a lot with pre-allocated buffers, but my admiration ends where segfaults
> begin.

Yes, truncating is needed. I will try to add it to the patch. A Large Enough® 
buffer is not useful, because someone could have a replace rule like this:
(replace subrule (GNU "GNU's Not Unix") (<other replace rules>) ...)

The patch I sent stops circular substitutions of depth 1:
(replace subrule (rr rr) (<other replace rules>) ... )
But I have to make it stop circular substitutions of depth n by storing all 
results before substitution and check each result after substitution against 
the list. Here is an example of depth 3:
(replace subrule (ål mora) (ora orsa) (morsa ål))


> I added a patch about a month ago that did address some of these buffer
> overflows (by using dynamic allocation), and I didn't get any negative
> feedback about it, __FWIW.

Sounds good!