DP downloads rules for the user, searching for the keyword ALL, username, #uid, %group, +* (all netgroups). Before it stores these rules into the sysdb, it purges the cache using the same filter.

This can cause problems in following situation:

• we have users A and B
• rule R will match for both users by their name or uid (there is no problem for the groups or netgroups)
• the rule is stored in the sysdb
• A is removed from R
• A runs sudo which causes deletion of R
• DP goes offline
• B is unable to run sudo beacuse R is deleted

The purging algorithm should work like:
1. delete all rules containing netgroups (they will be all stored again anyway)
2. retrieve all rules that contains username/#uid/%group
3. remove ALL/username/#uid/%group from sudoUser attribute
4. delete rule if sudoUser attribute is empty