Re: [Doxygen-develop] segfault with cyclic subgroups

[Dimitri v. H. <do...@gm...>]

Hi Helmut,

> On 01 Nov 2014, at 18:02 , Helmut Grohne <he...@su...> wrote:
> 
> Dear Doxygen developers,
> 
> I am faced with a segmentation fault of Doxygen 1.8.8 (as used by Debian
> unstable on amd64) when trying to process the following (invalid?)
> header:
> 
> | /**
> |  * @addtogroup foo1 foo2
> |  * @{
> |  * @addtogroup foo4 foo5
> |  * @{
> |  * @defgroup foo1 foo3
> |  * @}
> |  * @}
> |  */
> 
> While this example looks artificial, it was processed by earlier
> versions of Doxygen and the Enlightenment libraries reproduce the same
> segmentation fault (see https://bugs.debian.org/762272).
> 
> What happens is that stack space is exhausted in a recursion of
> recursivelyAddGroupListToTitle. Turns out the recursion alternates
> between group foo1 and foo4. Conceptually, I have no clue what cyclic
> subgroup membership is supposed to mean. One way to look at this problem
> is to argue that Doxygen fails to refuse processing cyclic subgroups.
> Alternatively the depth of the recursion can be limited.
> 
> I am proposing the attached patch (suitable to "git am") to make Doxygen
> error out when faced with cyclic subgroups. Is this patch reasonable for
> inclusion upstream and does it fully fix the problem?

It think it will still fail on larger cycles, e.g.: a->b->c->a

> 
> I would like to add some minimal fix to the Debian package as Debian
> jessie is almost frozen (i.e. a new upstream release of Doxygen cannot
> be added to Debian atm).
> 

I've pushed a variation of your patch:
https://github.com/doxygen/doxygen/commit/c83db38ea83499be19d9ff242bfa22ae534ee80c
Let me know if it solves the problem.

Regards,
  Dimitri