Empty Polygon

[juliusfriedman]

I am having issues writing an Empty Polygon:

 Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.ArgumentException: Ring has fewer than 4 points, so orientation cannot be determined (Parameter 'ring')

Is there an easy way around this?

I can read them just fine but can't insert what I read if I needed to...

I have manually inserted an Empty Polygon using SQL and have resorted to copying it with SQL when after I insert with NULL in that column I would otherwise have the Empty Polygon, I could also use a Trigger but that is even nastier.

See also
#9
#4

[airbreather]

Eww -- there's no specific repro here to confirm, but I think it's probably this line that's throwing the underlying exception because there's no "is it empty?" check.

As a workaround, I would recommend using an empty instance of some other geometry type, such as an empty MultiPolygon.

[juliusfriedman]

Can't use a MULTIPOLYGON because the type on the model is Polygon but I can issue a manual INSERT with the desired SQL since I know all the other field values.

Eager to see this fixed

[roji]

We seem to be seeing the same thing via EF Core in dotnet/efcore#24621. Note the possible similarity with NetTopologySuite/NetTopologySuite.IO.PostGis#14 (same bug?).

[FObermaier]

... but I think it's probably this line that's throwing the underlying exception because there's no "is it empty?" check.

If it is, then the issue should be resolved with NTS v2.3 because the ArgumentException has been removed in favor of a default result value of false.

[rmja]

@FObermaier Would it be possible to get a 2.0.1 version with this fix?

[rmja]

@FObermaier ping:-)

[FObermaier]

Fixed with d859a1c

New package is out, too.