FIX: Handle empty points in geometry projection

lib/cartopy/crs.py

@@ -833,6 +833,8 @@ def project_geometry(self, geometry, src_crs=None):
         return getattr(self, method_name)(geometry, src_crs)
 
     def _project_point(self, point, src_crs):
+        if point.is_empty:
+            return point
         return sgeom.Point(*self.transform_point(point.x, point.y, src_crs))
 
     def _project_line_string(self, geometry, src_crs):

lib/cartopy/tests/test_crs.py

@@ -314,6 +314,11 @@ def test_transform_points_empty():
     assert_array_equal(result, np.array([], dtype=np.float64).reshape(0, 3))
 
 
+def test_project_geometry_empty_point():
+    """Test with an empty shapely point."""
+    assert ccrs.PlateCarree().project_geometry(sgeom.Point()).is_empty
+
+
 def test_transform_points_outside_domain():
     """Test CRS.transform_points with out of domain arrays."""
     # Length-1 arrays error out with a bad status code, while