Hello,

I have a workspace where polygons and points are combined using a NeighborFinder, creating a list of points close to my polygons. Depending on my inputs (various .csv files), these points have different existing attributes and many that are missing. My method for finding the highest value per polygon for all nearby points was to sort the resulting list of close candidates by descending value, and then use an AttributeCreator to extract the list{0}.attribute value to a proper attribute. I do this for about a dozen attributes, some of which are missing, depending on my input data.

My problem occurs when the ListSorter gets to one of these missing attributes. My expectation was that the list{0}.attribute would simply pass on a null or missing value, but what happens instead is that the list is removed entirely, or at least all list elements seem to be. Inspecting my polygons immediately after the ListSorter shows that none of my polygons have a list value anymore. Is this intended behavior, and if so, why?

Other attributes within the same list element still have values so removing the elements entirely because of a failed Sort seems rather rigorous.