[geos-devel] Crash when buffering a geometry

[Martin Davis]

FWIW, this test case works in the current JTS codebase, but apparently 
not in JTS 1.9.  So this might narrow down where to look.  There has 
been at least one change to the buffering code since 1.9, to do with 
improving how offset curve generation is handled.

Stephen Wong wrote:
> Hi Paul,
>
> Thanks for the quick response. I just ran the test again (Windows 
> Vista, 32-bit) and it doesn't get stuck on reading the WKB, so maybe 
> it has to do with cross-platform compatibility.  I took the WKB and 
> converted it to hex, so hopefully, it will work this time. I've 
> attached it to the ticket (http://trac.osgeo.org/geos/ticket/188). The 
> file I/O operations in the .cpp file now look like this:
>
> std::ifstream fin ;
> fin.open( "hex.ogc" ) ;
> GeometryAPtr geom( reader_.readHEX( fin ) ) ;
>
> Thanks,
>
> Stephen
>
> On Mon, Aug 11, 2008 at 11:42 AM, Paul Ramsey 
> <pramsey at cleverelephant.ca <mailto:pramsey at cleverelephant.ca>> wrote:
>
>     Stephen,
>
>     When I integrate your code into my OS/X build and run the unit tests,
>     I don't get as far as buffering...
>
>     ---> group: geos::operation::BufferOp, test: test<1>
>         problem: unexpected exception
>         exception typeid: N4geos2io14ParseExceptionE
>         message: "ParseException: Unknown WKB type 0"
>
>     Are you certain that WKB fragment is good?
>
>     Paul
>
>     On Fri, Aug 8, 2008 at 11:48 AM, Stephen Wong <swongu at gmail.com
>     <mailto:swongu at gmail.com>> wrote:
>     > Hello,
>     > I have found that when using BufferOp on a specific polygon,
>     GEOS crashes
>     > with an assertion failure.  This failure appears to be within
>     > RightmostEdgeFinder, and I have documented it on a ticket
>     > (http://trac.osgeo.org/geos/ticket/188). On that ticket, I have also
>     > provided a .zip file that reproduces the error. The surprising
>     this is that
>     > the geometry is not complicated at all!
>     > I have posted this problem in March
>     > (see
>     http://lists.osgeo.org/pipermail/geos-devel/2008-March/003324.html),
>     > but didn't get a response thus far; hopefully posting here will
>     help.
>     >  Thanks in advance.
>     > Regards,
>     > Stephen
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-- 
Martin Davis
Senior Technical Architect
Refractions Research, Inc.
(250) 383-3022