Geometry Boost List: Re: [geometry] access violation in update_discarded(...)

Subject: Re: [geometry] access violation in update_discarded(...)
From: Menelaos Karavelas (menelaos.karavelas_at_[hidden])
Date: 2014-10-27 14:51:21

Hi Volker.

On 27/10/2014 07:39 ??, Volker Schöch wrote:
>
> Hi,
>
> Unfortunately I have not hear from you in this regard. It seems that I 
> still cannot reliably reproduce the issue, but when it occurs, it 
> occurs in the following scenario. Apparently, something is broken in 
> your memory management:
>
> { // RT#8837
>
> _intPolygonpolygonA;
>
>        boost::geometry::read_wkt("MULTIPOLYGON(((488 2035,527 2035,527 
> 2093,488 2093)))", polygonA); // does not throw
>
> _intRectrectB;
>
>        boost::geometry::read_wkt("BOX(417 2064,597 2064)", rectB); // 
> does not throw
>
> _intPolygonpolygonC;
>
>        boost::geometry::difference(polygonA, rectB, polygonC); // 
> ACCESS VIOLATION
>
> }
>
> Maybe you could make an effort and step through this simple example 
> once to see if everything works as expected?
>
> I understand that the box and/or the polygon may not conform to all 
> requirements (not spike-free etc.) but in any case, IMO the geometry 
> library should not crash with a memory fault.
>
> As always, my *points are based on int* and my polygons are 
> *counter-clockwise* and *not closed*.
>

Please see the attached program and its output, which works for me.
Do you think you can reproduce the problem in a standalone program?

All the best,

- m.

> Regards
>
>    Volker
>
> --
> Volker Schöch | vschoech_at_[hidden] <mailto:vschoech_at_[hidden]>
> Senior Software Engineer
>
>
> *We are looking for C++ Developers:* http://www.think-cell.com/career
>
> *From:*Geometry [mailto:geometry-bounces_at_[hidden]] *On Behalf 
> Of *Volker Schöch
> *Sent:* Freitag, 17. Oktober 2014 16:20
> *To:* Boost.Geometry library mailing list (geometry_at_[hidden])
> *Subject:* [geometry] access violation in update_discarded(...)
>
> Hi,
>
> we have seen an access violation deep inside boost geometry. We are 
> still working on a simple reproduction, which may take while. In the 
> meantime, maybe you have some idea what went wrong, or some suggestion 
> how to avoid this situation?
>
> Here is where it happened:
>
> template<typenameTurns, typenameOperations>
>
> inlinevoidupdate_discarded(Turns& turn_points, Operations& operations)
>
> {
>
> // Vice-versa, set discarded to true for discarded operations;
>
> // AND set discarded points to true
>
> for(typenameboost::range_iterator<Operations>::typeit = 
> boost::begin(operations);
>
>          it != boost::end(operations);
>
>          ++it)
>
>     {
>
> if(turn_points[it->index].discarded) 
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< access violation
>
>         {
>
>             it->discarded = true;
>
>         }
>
> elseif(it->discarded)
>
>         {
>
> turn_points[it->index].discarded = true;
>
>         }
>
>     }
>
> }
>
> Please find the callstack attached.
>
> Regards
>
>    Volker
>
> --
> Volker Schöch | vschoech_at_[hidden] <mailto:vschoech_at_[hidden]>
> Senior Software Engineer
>
>
> *We are looking for C++ Developers:*http://www.think-cell.com/career
>
> ------------------------------------------------------------------------
>
> think-cell Software GmbH
>
> 	
>
> http://www.think-cell.com <http://www.think-cell.com/>
>
> Chausseestr. 8/E
>
> 	
>
> phone / fax
>
> 	
>
> [phone] / -19
>
> 10115 Berlin, Germany
>
> 	
>
> US phone / fax
>
> 	
>
> [phone] / [phone]
>
> Amtsgericht Berlin-Charlottenburg, HRB 85229 | European Union VAT Id 
> DE813474306
>
> Directors: Dr. Markus Hannebauer, Dr. Arno Schödl
>
>
>
> _______________________________________________
> Geometry mailing list
> Geometry_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/geometry