It's possible to call event_tags_for_ruleset/evttypes_for_ruleset for a
ruleset that hasn't been loaded. In this case, it's possible to go past
the end of the m_rulesets array.
After fixing that, it's also possible to go past the end of the
event_tags array in event_tags_for_ruleset().
So in both cases, check the index against the array size before
indexing.