When the cylinders became a dynamic data structure, a get_cylinder() call
suddenly could return a NULL pointer. So use get_or_create_cylinder() for the
first call when parsing the user's data.
Also, deal with an oddity where the string lists look different because an
empty list technically isn't the same as a list with one empty string.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
988ccba710