DbfReader throws error when trying to parse NULL Date fields

[kyleeinspahr]

When evaluating the DbfReader Enumerable of a shapefile that has a Date column with NULL values, it throws the following error:
The DateTime represented by the string '00000000' is not supported in calendar 'System.Globalization.GregorianCalendar'.

Before that, I examined the Fields collection and it even reports that the Value is null:

Here is a file that shows the issue
ShapefileWithNULLDate.zip

[KubaSzostak]

Hi @kyleeinspahr, I checked the ShapefileWithNULLDate.shp file using following code and everything works fine. Can you provide a sample code that demonstrates the issue?

var shpPath = TestShapefiles.PathTo("Issues/061/ShapefileWithNULLDate.shp");
using var shpReader = Shapefile.OpenRead(shpPath);

while (shpReader.Read())
{
    var smapleId = shpReader.Fields["SAMPLEID"].Value ?? "<null>";
    var eventDate = shpReader.Fields["EVENT_DATE"].Value ?? "<null>";
    Console.WriteLine($"SAMPLEID: {smapleId},   EVENT_DATE: {eventDate}");
}

Output:

SAMPLEID: 1,   EVENT_DATE: <null>
SAMPLEID: 2,   EVENT_DATE: <null>
SAMPLEID: 3,   EVENT_DATE: <null>
SAMPLEID: 4,   EVENT_DATE: <null>
SAMPLEID: 5,   EVENT_DATE: <null>