The source project of this merge request has been removed.
Instead of detecting cycles exactly, only avoid runaway expansion of paths which is much cheaper.
This is a follow-up of !349 (merged) which significantly improves the efficiency of our defence against cycles (trading it against accuracy which seems unimportant). In contrast to !349 (merged) it has not been tested against a fully populated SNS cache showing the original issue.
Edited by Adam Reichold