On Thu, Oct 25, 2018, 01:40 Mateusz Loskot via Geometry <geometry@lists.boost.org> wrote:
On Wed, 24 Oct 2018 at 23:14, Nicolas Troncoso <ntroncos@gmail.com> wrote:
> On Wed, Oct 24, 2018 at 12:44 PM Mateusz Loskot via Geometry <geometry@lists.boost.org> wrote:
>>
>> It seems that DB-based approach may be easier for you than C++.
>>
>> I'd rather use PostGIS to validate geometries, especially regarding
>> OGC compliance
>>
>
> As you suggested I went on the DB route. These are my findings for future reference:
>  I ran the same (or equivalent where applicable) query in:
> MySql 5.6: Success
> MySql 5.7.23: Failure
> MySql 8.0.12: Success
> Postgres server 10.5: Success
> MSSQL 2016: Success
>
> I attach the query for the curious.

Thanks.

I think the results are enough to assume validity checks in MySQL 5.7
are not reliable.

I've checked your geometry with PostGIS 2.1. It's valid there too.

Yesterday I opened a bug report in MySQL

https://bugs.mysql.com/?id=92937

Thanks for the help.

Cheers.