Segfault on isValid

[thomersch]

I encountered a weird issue that seems only to come up on macOS, but also concerns calls from PostGIS.

When I execute

SELECT ST_StraightSkeleton(
	ST_Buffer(
		ST_GeomFromEWKT('SRID=3857;LINESTRING (1 1, 5 5)'), 1
	)
);

the database segfaults.

So I started to hunt down the problem and was able to reduce it to the following small C++ snippet:

#include <iostream>

#include <SFCGAL/Polygon.h>
#include <SFCGAL/algorithm/isValid.h>

int main(int argc, const char * argv[]) {
	SFCGAL::Polygon poly;
	poly.exteriorRing().addPoint(SFCGAL::Point(2, 1));
	poly.exteriorRing().addPoint(SFCGAL::Point(1, 0));
	poly.exteriorRing().addPoint(SFCGAL::Point(0, 1));
	poly.exteriorRing().addPoint(SFCGAL::Point(1.01, 2));
	poly.exteriorRing().addPoint(SFCGAL::Point(2, 1));
	
	std::cout << SFCGAL::algorithm::isValid(poly) << std::endl;
	return 0;
}

This runs fine on Linux, but not on macOS. Not sure where the issue originates, but I saw that in those cases libgmp receives some very suspicious data structures which contain null pointers.

sfcgal 1.3.7, cgal 4.14.1, gmp 6.2.0

[lbartoletti]

It's fine too on FreeBSD

Confirmed on MacOs Catalina, sfcgal 1.3.7, cgal 4.14.1, gmp 6.1.2 with clang and gcc

The backtrace

Process 57688 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
    frame #0: 0x0000000100cd339f libgmp.10.dylib`mpq_cmp_numden + 112
libgmp.10.dylib`mpq_cmp_numden:
->  0x100cd339f <+112>: movq   -0x8(%rcx,%rsi,8), %r9
    0x100cd33a4 <+117>: movq   %r9, %rcx
    0x100cd33a7 <+120>: orq    %rsi, %rcx
    0x100cd33aa <+123>: xorl   %r8d, %r8d
Target 0: (a.out) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
  * frame #0: 0x0000000100cd339f libgmp.10.dylib`mpq_cmp_numden + 112
    frame #1: 0x0000000100272087 libSFCGAL.1.dylib`CGAL::CartesianKernelFunctors::Compare_xy_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >::operator()(CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > const&, CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > const&) const + 27
    frame #2: 0x0000000100271c76 libSFCGAL.1.dylib`bool CGAL::Intersections::internal::do_intersect<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >(CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > const&) + 54
    frame #3: 0x000000010028727a libSFCGAL.1.dylib`CGAL::Intersections::internal::Segment_2_Segment_2_pair<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >::intersection_type() const + 66
    frame #4: 0x0000000100287082 libSFCGAL.1.dylib`CGAL::Intersection_traits<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2>::result_type CGAL::Intersections::internal::intersection<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >(CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > const&) + 42
    frame #5: 0x000000010015b98b libSFCGAL.1.dylib`CGAL::Lazy_rep_2<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, CGAL::CommonKernelFunctors::Intersect_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CommonKernelFunctors::Intersect_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Epeck>, CGAL::Segment_2<CGAL::Epeck> >::update_exact() const + 117
    frame #6: 0x000000010015c593 libSFCGAL.1.dylib`CGAL::Lazy_rep_1<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::internal::Variant_cast<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > >, CGAL::internal::Variant_cast<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > >, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL::Lazy<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > > >::update_exact() const + 53
    frame #7: 0x000000010011f2d4 libSFCGAL.1.dylib`CGAL::Lazy_rep_1<CGAL::Interval_nt<false>, CGAL::Gmpq, CGAL::CartesianKernelFunctors::Compute_x_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CartesianKernelFunctors::Compute_x_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::To_interval<CGAL::Gmpq>, CGAL::Point_2<CGAL::Epeck> >::update_exact() const + 48
    frame #8: 0x000000010025ac2e libSFCGAL.1.dylib`bool CGAL::operator==<CGAL::Gmpq, CGAL::Gmpq>(CGAL::Lazy_exact_nt<CGAL::Gmpq> const&, CGAL::Lazy_exact_nt<CGAL::Gmpq> const&) + 106
    frame #9: 0x000000010011d518 libSFCGAL.1.dylib`SFCGAL::Coordinate::operator==(SFCGAL::Coordinate const&) const + 344
    frame #10: 0x000000010026f631 libSFCGAL.1.dylib`bool SFCGAL::algorithm::selfIntersectsImpl<2>(SFCGAL::LineString const&) + 1171
    frame #11: 0x000000010028cf35 libSFCGAL.1.dylib`SFCGAL::algorithm::isValid(SFCGAL::Polygon const&, double const&) + 948
    frame #12: 0x000000010028c2f4 libSFCGAL.1.dylib`SFCGAL::algorithm::isValid(SFCGAL::Geometry const&, double const&) + 297
    frame #13: 0x0000000100000c74 a.out`main(argc=1, argv=0x00007ffeefbffa28) at test_sfcgal.cpp:14:15
    frame #14: 0x00007fff6effb7fd libdyld.dylib`start + 1
    frame #15: 0x00007fff6effb7fd libdyld.dylib`start + 1

[HorayNarea]

I can confirm the crash on OpenBSD with gmp 6.1.2, cgal 4.14.2 and sfcgal 1.3.7:

obsd# lldb -c a.out.core -f a.out                                                                                                                                                                                                            
(lldb) target create "a.out" --core "a.out.core"
Core file '/root/a.out.core' (x86_64) was loaded.
(lldb) bt
* thread #1, stop reason = signal SIGSEGV
  * frame #0: 0x00000906a17c5345 libgmp.so.10.0`mpq_cmp_numden + 101
    frame #1: 0x0000090665abdaea libSFCGAL.so.1`boost::multiprecision::backends::gmp_rational::compare(boost::multiprecision::backends::gmp_rational const&) const + 42
    frame #2: 0x0000090665abd9fe libSFCGAL.so.1`CGAL::RET_boost_mp_base<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Compare::operator()(boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&) const + 62
    frame #3: 0x0000090665ad386e libSFCGAL.so.1`CGAL::Real_embeddable_traits<CGAL::Coercion_traits<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Type>::Compare::result_type CGAL::compare<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >(boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&) + 46
    frame #4: 0x0000090665ad4352 libSFCGAL.so.1`CGAL::Compare<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::result_type CGAL::compare_lexicographically_xyC2<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >(boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> const&) + 50
    frame #5: 0x0000090665ad4305 libSFCGAL.so.1`CGAL::CartesianKernelFunctors::Compare_xy_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >::operator()(CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > const&, CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > const&) const + 101
    frame #6: 0x0000090665bbfe29 libSFCGAL.so.1`bool CGAL::Intersections::internal::do_intersect<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >(CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > const&) + 2617
    frame #7: 0x0000090665bbe47e libSFCGAL.so.1`CGAL::Intersections::internal::Segment_2_Segment_2_pair<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >::intersection_type() const + 94
    frame #8: 0x0000090665bbe1af libSFCGAL.so.1`CGAL::Intersection_traits<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2>::result_type CGAL::Intersections::internal::intersection<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >(CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >::Segment_2 const&, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > const&) + 95
    frame #9: 0x0000090665baf449 libSFCGAL.so.1`CGAL::Intersection_traits<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > >::result_type CGAL::CommonKernelFunctors::Intersect_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >::operator()<CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > >(CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > const&, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > const&) const + 57
    frame #10: 0x0000090665baf86f libSFCGAL.so.1`CGAL::Lazy_rep_2<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > > >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > >, CGAL::CommonKernelFunctors::Intersect_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CommonKernelFunctors::Intersect_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Epeck>, CGAL::Segment_2<CGAL::Epeck> >::update_exact() const + 191
    frame #11: 0x0000090665bb8eef libSFCGAL.so.1`CGAL::Lazy_rep<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > > >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > >, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > >::exact() + 63
    frame #12: 0x0000090665bb8e87 libSFCGAL.so.1`CGAL::Lazy<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > > >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > >, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > >::exact() const + 39
    frame #13: 0x0000090665bb83af libSFCGAL.so.1`boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > > const& CGAL::exact<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > > >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > >, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > >(CGAL::Lazy<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > > >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > >, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > > const&) + 31
    frame #14: 0x0000090665bb7701 libSFCGAL.so.1`CGAL::Lazy_rep_1<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::internal::Variant_cast<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > >, CGAL::internal::Variant_cast<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > >, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL::Lazy<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > > >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > > >, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Cartesian_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > > >::update_exact() const + 97
    frame #15: 0x00000906659e9bcf libSFCGAL.so.1`CGAL::Lazy_rep<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::Cartesian_converter<CGAL::Simple_cartesian<CGAL::Gmpq>, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<CGAL::Gmpq, CGAL::Interval_nt<false> > > >::exact() + 63
    frame #16: 0x00000906659e9b67 libSFCGAL.so.1`CGAL::Lazy<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::Gmpq, CGAL::Cartesian_converter<CGAL::Simple_cartesian<CGAL::Gmpq>, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<CGAL::Gmpq, CGAL::Interval_nt<false> > > >::exact() const + 39
    frame #17: 0x00000906659e8f8f libSFCGAL.so.1`CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Gmpq> > const& CGAL::exact<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::Gmpq, CGAL::Cartesian_converter<CGAL::Simple_cartesian<CGAL::Gmpq>, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<CGAL::Gmpq, CGAL::Interval_nt<false> > > >(CGAL::Lazy<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::Gmpq, CGAL::Cartesian_converter<CGAL::Simple_cartesian<CGAL::Gmpq>, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >, CGAL::NT_converter<CGAL::Gmpq, CGAL::Interval_nt<false> > > > const&) + 31
    frame #18: 0x00000906659e92c1 libSFCGAL.so.1`CGAL::Lazy_rep_1<CGAL::Interval_nt<false>, CGAL::Gmpq, CGAL::CartesianKernelFunctors::Compute_x_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CartesianKernelFunctors::Compute_x_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::To_interval<CGAL::Gmpq>, CGAL::Point_2<CGAL::Epeck> >::update_exact() const + 97
    frame #19: 0x00000906659dbc3f libSFCGAL.so.1`CGAL::Lazy_rep<CGAL::Interval_nt<false>, CGAL::Gmpq, CGAL::To_interval<CGAL::Gmpq> >::exact() + 63
    frame #20: 0x00000906659dbbd7 libSFCGAL.so.1`CGAL::Lazy<CGAL::Interval_nt<false>, CGAL::Gmpq, CGAL::Lazy_exact_nt<CGAL::Gmpq>, CGAL::To_interval<CGAL::Gmpq> >::exact() const + 39
    frame #21: 0x00000906659d3b98 libSFCGAL.so.1`bool CGAL::operator==<CGAL::Gmpq, CGAL::Gmpq>(CGAL::Lazy_exact_nt<CGAL::Gmpq> const&, CGAL::Lazy_exact_nt<CGAL::Gmpq> const&) + 184
    frame #22: 0x00000906659d2621 libSFCGAL.so.1`SFCGAL::Coordinate::operator==(SFCGAL::Coordinate const&) const + 897
    frame #23: 0x0000090665a1d6ad libSFCGAL.so.1`SFCGAL::Point::operator==(SFCGAL::Point const&) const + 61
    frame #24: 0x00000906660082a7 libSFCGAL.so.1`bool SFCGAL::algorithm::selfIntersectsImpl<2>(SFCGAL::LineString const&) + 2103
    frame #25: 0x0000090666006bff libSFCGAL.so.1`SFCGAL::algorithm::selfIntersects(SFCGAL::LineString const&) + 31
    frame #26: 0x0000090666020985 libSFCGAL.so.1`SFCGAL::algorithm::isValid(SFCGAL::Polygon const&, double const&) + 853
    frame #27: 0x000009066601fe18 libSFCGAL.so.1`SFCGAL::algorithm::isValid(SFCGAL::Geometry const&, double const&) + 472
    frame #28: 0x00000903b13746b7 a.out`main(argc=1, argv=0x00007f7ffffcc7e8) at crash.cpp:14:15
    frame #29: 0x00000903b137413b a.out`___start + 283

[HorayNarea]

I can also confirm the crash on Windows 10 with cgal 4.14.2, sfcgal 1.3.7 and gmp 6.1.2 cross-compiled with mingw-w64

Backtrace when run under cygwin (until I figure out how I use gdb/lldb native):

#0  0x000000006ad096d0 in libgmp-10!.gmpn_copyi () from /cygdrive/c/Users/User/Desktop/libgmp-10.dll
#1  0x000000006d56d57b in boost::array<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, 2ull>::array(boost::array<boost:
:multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, 2ull> const&) () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#2  0x000000006d5dc567 in CGAL::Lazy_rep_3<CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision:
:backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::CommonKernelFunctors::Construct_segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CommonKernel
Functors::Construct_segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Cartesia
n_converter<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Inter
val_nt<false> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL:
:Return_base_tag, CGAL::Point_2<CGAL::Epeck>, CGAL::Point_2<CGAL::Epeck> >::update_exact() const () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#3  0x000000006d5c67c1 in CGAL::Lazy_rep_2<boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false
> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::det
ail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::voi
d_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, boost::optional<boost::variant<CGAL::Poin
t_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<b
oost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost:
:detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant:
:void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::de
tail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, CGAL::CommonKernelFunctors::Intersect_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CommonKernelFunct
ors::Intersect_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Cartesian_converter<C
GAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false>
 >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL::Segment_2<CG
AL::Epeck>, CGAL::Segment_2<CGAL::Epeck> >::update_exact() const () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#4  0x000000006d5bfb9a in CGAL::Lazy_rep_1<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::bac
kends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::internal::Variant_cast<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > > >, CGAL::internal::Variant_c
ast<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > > >, CGAL::Cartesian_converte
r<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<fal
se> >, CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > >, CGAL::Lazy<boos
t::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::Segment_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, boost::detail::variant::void_, boost::de
tail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::vo
id_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detai
l::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> >, boost::optional<boost::variant<CGAL::Point_2<CGAL::Simple_cartesian<boost::multiprecisio
n::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, CGAL::Segment_2<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecis
ion::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> > >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant
::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::d
etail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::v
oid_, boost::detail::variant::void_> >, boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Cartesian_converter<CGAL:
:Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1> >, CGAL::Simple_cartesian<CGAL::Interval_nt<false> >,
CGAL::NT_converter<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, (boost::multiprecision::expression_template_option)1>, CGAL::Interval_nt<false> > > > >::update_exact() con
st () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#5  0x000000006d5bb779 in CGAL::Lazy_rep_1<CGAL::Interval_nt<false>, CGAL::Gmpq, CGAL::CartesianKernelFunctors::Compute_x_2<CGAL::Simple_cartesian<CGAL::Interval_nt<false> > >, CGAL::CartesianKernelFunct
ors::Compute_x_2<CGAL::Simple_cartesian<CGAL::Gmpq> >, CGAL::To_interval<CGAL::Gmpq>, CGAL::Point_2<CGAL::Epeck> >::update_exact() const () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#6  0x000000006d546659 in bool CGAL::operator==<CGAL::Gmpq, CGAL::Gmpq>(CGAL::Lazy_exact_nt<CGAL::Gmpq> const&, CGAL::Lazy_exact_nt<CGAL::Gmpq> const&) ()
   from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#7  0x000000006d2421b9 in SFCGAL::Coordinate::operator==(SFCGAL::Coordinate const&) const () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#8  0x000000006d5a7c3f in bool SFCGAL::algorithm::selfIntersectsImpl<2>(SFCGAL::LineString const&) () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#9  0x000000006d29797d in SFCGAL::algorithm::isValid(SFCGAL::Polygon const&, double const&) () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#10 0x000000006d29a739 in SFCGAL::algorithm::isValid(SFCGAL::Geometry const&, double const&) () from /cygdrive/c/Users/User/Desktop/libSFCGAL.dll
#11 0x00000000004017e0 in main ()

[danielcumberbatch1]

The specified snippet application runs fine:

$ cat main.cpp
#include <iostream>

#include <SFCGAL/Polygon.h>
#include <SFCGAL/algorithm/isValid.h>

int main()
{
  SFCGAL::Polygon poly;
  poly.exteriorRing().addPoint(SFCGAL::Point(2, 1));
  poly.exteriorRing().addPoint(SFCGAL::Point(1, 0));
  poly.exteriorRing().addPoint(SFCGAL::Point(0, 1));
  poly.exteriorRing().addPoint(SFCGAL::Point(1.01, 2));
  poly.exteriorRing().addPoint(SFCGAL::Point(2, 1));
  
  std::cout << SFCGAL::algorithm::isValid(poly) << std::endl;

  return 0;
}
$ g++ -o main  main.cpp --std=c++11 -lSFCGAL -lCGAL
$ ./main
1

when using the following environment:

Operating system: Mac OS X 64bit
Compiler: Apple LLVM version 8.0.0 (clang-800.0.42.1)
Build type: Release
Specific flags: --std=c++11
SFCGAL Commit: 787e2b7
CGAL Version: CGAL-4.12
Boost Version: 1.72.0
GMP Version: 6.1.2
MPFR Version: 4.0.2

[james-newtracs]

Hi, we're experiencing this issue also. Does anyone have a workaround until its resolved? How can we fall back to a previous version of SFGCAL? Running latest versions of Postgres & Postgis via homebrew.

[james-newtracs]

I encountered a weird issue that seems only to come up on macOS, but also concerns calls from PostGIS.

When I execute

SELECT ST_StraightSkeleton(
	ST_Buffer(
		ST_GeomFromEWKT('SRID=3857;LINESTRING (1 1, 5 5)'), 1
	)
);

the database segfaults.

So I started to hunt down the problem and was able to reduce it to the following small C++ snippet:

#include <iostream>

#include <SFCGAL/Polygon.h>
#include <SFCGAL/algorithm/isValid.h>

int main(int argc, const char * argv[]) {
	SFCGAL::Polygon poly;
	poly.exteriorRing().addPoint(SFCGAL::Point(2, 1));
	poly.exteriorRing().addPoint(SFCGAL::Point(1, 0));
	poly.exteriorRing().addPoint(SFCGAL::Point(0, 1));
	poly.exteriorRing().addPoint(SFCGAL::Point(1.01, 2));
	poly.exteriorRing().addPoint(SFCGAL::Point(2, 1));
	
	std::cout << SFCGAL::algorithm::isValid(poly) << std::endl;
	return 0;
}

This runs fine on Linux, but not on macOS. Not sure where the issue originates, but I saw that in those cases libgmp receives some very suspicious data structures which contain null pointers.

sfcgal 1.3.7, cgal 4.14.1, gmp 6.2.0

@thomersch were you able to find a solution to this issue?