Geometry checker accepts invalid polygon

[jleedev]

What is the bug or the crash?

"Check validity" with GEOS method correctly finds the error in this polygon. With QGIS method it does not.

Steps to reproduce the issue

thing.csv

 ¶ ogrinfo --version
GDAL 3.6.2, released 2023/01/02
 ¶ cat thing.csv
WKT,
"POLYGON((0 0,10 0,10 10,0 10,0 0),(5 8,4 7,5 6,6 7,5 8),(5 6,4 5,5 4,6 5,5 6),(6 5,7 4,8 5,7 6,6 5),(7 6,8 7,7 8,6 7,7 6))",
 ¶ ogrinfo -q thing.csv -dialect sqlite -sql 'select ST_IsValidReason(GEOMETRY) from thing'

Layer name: SELECT
OGRFeature(SELECT):0
  ST_IsValidReason(GEOMETRY) (String) = Interior is disconnected[6 5]

Versions

<style type="text/css"> p, li { white-space: pre-wrap; } </style>

QGIS version	3.34.15-Prizren	QGIS code branch	Release 3.34
Qt version	5.15.8
Python version	3.11.2
GDAL/OGR version	3.6.2
PROJ version	9.1.1
EPSG Registry database version	v10.076 (2022-08-31)
GEOS version	3.11.1-CAPI-1.17.1
SQLite version	3.40.1
PostgreSQL client version	15.10 (Debian 15.10-0+deb12u1)
SpatiaLite version	5.0.1
QWT version	6.1.4
QScintilla2 version	2.13.3
OS version	Debian GNU/Linux 12 (bookworm)
Active Python plugins
MetaSearch	0.3.6
db_manager	0.1.20
grassprovider	2.12.99
processing	2.12.99

QGIS version 3.34.15-Prizren QGIS code branch [Release 3.34](https://github.com/qgis/QGIS/tree/release-3_34) Qt version 5.15.8 Python version 3.11.2 GDAL/OGR version 3.6.2 PROJ version 9.1.1 EPSG Registry database version v10.076 (2022-08-31) GEOS version 3.11.1-CAPI-1.17.1 SQLite version 3.40.1 PostgreSQL client version 15.10 (Debian 15.10-0+deb12u1) SpatiaLite version 5.0.1 QWT version 6.1.4 QScintilla2 version 2.13.3 OS version Debian GNU/Linux 12 (bookworm)

Active Python plugins
MetaSearch
0.3.6
db_manager
0.1.20
grassprovider
2.12.99
processing
2.12.99

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response

[elpaso]

Cannot reproduce on current master.

[agiudiceandrea]

@elpaso, you need to set the METHOD: 1 (QGIS).

[jleedev]

Reproduced on 3.41.0 master for bookworm:

[elpaso]

Looking at the code of the QGIS implementation I think the check for disconnected rings was never implemented:
https://github.com/qgis/QGIS/blob/master/src/core/qgsgeometryvalidator.cpp#L211

I think this issue is probably more of a feature request than a bugfix, should we document the limitation of the QGIS method and recommend the more strict GEOS method?