[An extra null pointer check is not needed](https://isocpp.org/wiki/faq/freestore-mgmt#delete-handles-null "Do I need to check for null before delete p?") in [the function “List::Clear”](https://github.com/solvespace/solvespace/blob/d3da2c8b22d8f84e84adcce329e3b97a6a063e10/src/dsc.h#L286 "Update candidate").