[IRCServices Coding] Qline avoidance bug in /ns link nickname

[Mark Hetherington]

The protection of guest nicknames and qline protection within SQLINES and 
IRCD.CONF QLines can be circumvented via the use of the '/ns link' command:

nickserv/main: nick!user at host identified for nick Nick
nickserv/link: nick!user at host linked nick oper to Nick
nickserv/link: nick!user at host linked nick ircop to Nick
nickserv/link: nick!user at host linked nick admin to Nick
nickserv/link: nick!user at host linked nick Guest0 to Nick
nickserv/link: nick!user at host linked nick Guest1 to Nick
nickserv/link: nick!user at host linked nick Guest2 to Nick

... etc

I imagine protecting guest nicks will be a trivial matter of adding the 
same check as used in '/ns register' to the '/ns link' command. Protecting 
against standard QLines would like;y prove more complex. I am happy to 
move/add all QLines to SQLines if there is a way for services to support 
protection from registration when used in this manner. 

Although the QLines will probably still protect against these registered 
names being actually used, they will allow the primary nick to receive 
memos to these banned nicknames and I guess there is the potential for 
further problems. 

-- 
Mark.