Re: Why does this program segfault?

[Glenn Maynard <g_deb@zewt.org>]

On Wed, Jan 16, 2002 at 09:52:18PM +0100, Ulrich Eckhardt wrote:
> What does that have to do with Josip Rodin's comment about the sponsoring of 
> non-free packages ? (Hint: fix your mail-client)

I've already whined about this. :)

> > Is it because pkgDepCache has a virtual destructor?  If so am I supposed
> > to subclass it or am I just using it the wrong way?  (Sorry, the the
> > intricacies of C++ are a bit hazy for me and libapt-pkg is practically
> > undocumented.)
> >
> Hmmm, what about a backtrace ?

It's in the destructor of one of the package objects; I believe a
pointer is being freed twice.

> >   pkgDepCache cache = *cachefile;
> I am not sure if this is intended to be used that way, that is if the 
> copy-operation is really fully implemented (usually, you would rather not 
> copy the Object but ust pass references or pointers). Try to make this line 

The implicit copy ctor shouldn't be getting defined (there's a non-default
ctor), so I'm not sure exactly how that's being constructed.

> >   for (pkgCache::PkgIterator it = cache.PkgBegin(); !it.end(); it++)
> this loop is a bit different from typical C++, there you would probably have 
> something like 
> for (pkgCache::PkgIterator it = cache.PkgBegin(); it!=cache.PkgEnd(); ++it)
> but that is not necessarily wrong.

Comments in one of the headers say that it doesn't use the regular C++
iterator semantics.

-- 
Glenn Maynard