[gdal-dev] GPKG validation error from Teamengine

[Even Rouault]

On mardi 31 mars 2020 14:23:32 CEST Rahkonen Jukka (MML) wrote:
> Hi,
> 
> I have tested some GDAL made GeoPackages with Teamengine and it finds some
> errors where validate_gpkg.py does not. I am using the ets-gpkg12 test and
> its source code is at
> https://github.com/opengeospatial/ets-gpkg12/blob/master/src/main/java/org/
> opengis/cite/gpkg12/features/FeaturesTests.java
> 
> The test that fails is about requirement 78:
> // Verify the geometry envelope falls within the rtree extents for this
> instance // final String enveloperesult =
> geometryEnvelopeWithinExtents(envelopeVals, rtreeminmaxVals); // this test
> would test for the envelope within the rtree, not equal to
> 
> I wonder if this finding is worth making a GitHub issue or not. By the
> comment in the source code this test is known to be a bit problematic:
> final Double localtolerance = 1.0e-4;        // 1.0e-5 is not good enough
> for most geopackages to pass!

Jukka,

I see this test has been removed in the latest state of the spec:
https://github.com/opengeospatial/geopackage/commit/f2482abcc42a96b87dfd4970f9a1a08f493fc9b5#diff-c1aba1c1e37494be8225c64af76beb82

That the envelope in the GeoPackage geometry blob and the xmin,ymin,xmax,ymax value
from the RTree don't exactly match is expected, as the SQLite3 RTree mechanism
uses Float32 (see paragraph 3 of https://www.sqlite.org/rtree.html) instead of Float64
as in the envelope of the GPKG geometry blob.

validate_gpkg.py has never tested this, since it has not been created from the ATS
itself, but from the requirements, and probably an earlier version of the requirements
than 1.2.0 or later.

Even

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