ref: d3290195da55beae04d1bb86f811b6f8dd6b0663
parent: ba944f9f95238d0b820e63d9b6c2d83efc09b8a2
author: Ben Harris <bjh21@bjh21.me.uk>
date: Sun Jan 8 07:34:57 EST 2023
Untangle: forbid descriptions that connect a node to itself These cause an assertion failure in new_game(), so they should be rejected by validate_desc().