Deleting image asset leaves stale ImageViewer Image inspector choice

Deleting an image asset that is selected by an ImageViewer leaves the old asset name in the inspector Image dropdown. The deleted asset can remain shown as the selected value and as an option even though it is no longer present in the project assets. The expected behaviour is that deleting/removing image assets clears designer references to those assets so affected controls show (None) and the deleted names are not offered.