Fix #1373 -- Ignore empty geometries for SHP export (#1439)

* Fix #1373 -- Ignore empty geometries for SHP export

* Add test for `geometry=None`

cadasta/organization/download/shape.py

@@ -74,6 +74,10 @@ def write_features(self, ds, filename):
         layers = {}
 
         for su in spatial_units:
+            # Excluding empty geometries from export
+            if not su.geometry:
+                continue
+
             geom = ogr.CreateGeometryFromWkt(su.geometry.wkt)
             layer_type = geom.GetGeometryName().lower()
             layer = layers.get(layer_type, None)

cadasta/organization/tests/test_downloads.py

@@ -417,6 +417,14 @@ def test_write_features(self):
                      'MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)),'
                      '((15 5, 40 10, 10 20, 5 10, 15 5)))',
             attributes={'geom_type': 'multipolygon'})
+        su7 = SpatialUnitFactory.create(
+            project=project,
+            geometry='SRID=4326;POLYGON EMPTY',
+            attributes={'geom_type': 'empty'})
+        su8 = SpatialUnitFactory.create(
+            project=project,
+            geometry=None,
+            attributes={'geom_type': 'none'})
 
         dst_dir = os.path.join(settings.MEDIA_ROOT, 'temp/file4')
         ds = exporter.create_datasource(dst_dir)
@@ -430,6 +438,9 @@ def test_write_features(self):
             feature = layer.GetNextFeature()
             assert geom.equals(GEOSGeometry(feature.geometry().ExportToWkt()))
             assert feature.GetFieldAsString('id') == su.id
+
+            # Ensuring empty polygons are not added to shape
+            assert su.id not in [su7.id, su8.id]
         ds.Destroy()
 
         with open(filename) as csvfile:
@@ -449,6 +460,10 @@ def test_write_features(self):
                     assert row == [su5.id, su5.type, 'multilinestring']
                 if i == 6:
                     assert row == [su6.id, su6.type, 'multipolygon']
+                if i == 7:
+                    assert row == [su7.id, su7.type, 'empty']
+                if i == 8:
+                    assert row == [su8.id, su8.type, 'none']
 
         # remove this so other tests pass
         os.remove(filename)