Geometry Boost List: [geometry] Fwd: Found bug in Boost::geometry

Subject: [geometry] Fwd: Found bug in Boost::geometry
From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2012-10-17 08:27:14

Hi,

I received this report about problem with Boost.Geoemtry from Sergey,
one of SOCI users.
He asked me if I can forward it to the developers, so here it is:
(I hope the .cpp file attachment will get through.)

If this problem is confirmed as a bug, Sergey is willing to submit proper
report to the Boost Trac.

Mat

---------- Forwarded message ----------
From: Sergey Stepanov <net_storm_at_[hidden]>
Date: 17 October 2012 08:12
Subject: Found bug in Boost::geometry
To: Mateusz Loskot <mateusz_at_[hidden]>

Hello, Mateusz

I wasn't sure whom shall I contact, but since I know you for your great
effort in the SOCI development, I decided to ask you first.

If you know better person to contact, feel free to redirect me.
Our team found a very specific bug at the Boost::Geometry library.
Generally speaking on subtraction of two negative integer coordinates,
those are at the minimum limits we have problem.

Tracing into boost.geometry core we have found that in the file
sectionalize.hpp integer overflow happens in the following expression in
line 118:

coordinate_type const diff = geometry::get<1, Dimension>(seg) -
geometry::get<0, Dimension>(seg);

Here is a file in enclosure, which replicates that bug.
Or maybe it could be feature which we don`t know about =)

Stepanov Sergey
XMPP: netstrom_at_[hidden]
SKYPE: sergey.y.stepanov
mobile: [phone]