Project: moodle
Issue MDL-43511: question bank should not store references to MUC cache
MUC cache instances are cached internally, developers are expected to not store references to the cache returned from cache::make() because it breaks some types of MUC resets and probably when using different $identifiers parameter. I discovered this the hard way when hacking MUC in phpunit, the questions tests started breaking badly because of the $this->cache = cache::make('core', 'questiondata'); in question/engine/bank.php I was bitten by similar problem previously in dml drivers too...
Story points: 2