If the identifier used with /debug -i returns $false, mIRC should drop that line from the server without processing it at all.
This would make exploit blocking MUCH easier (and probably wouldn't take Khaled too long to implement). Currently, there are two bad methods of blocking exploits :
- using a proxy
- using /debug -i with /ignore -u
A proxy is very difficult to do in a transparent manner, so that commands like /server automatically use the proxy (not to mention changing the raw USER command so that it uses the server's address when connecting) and identifiers like $serverip return the server's IP and not 127.0.0.1.
/debug -i with /ignore -u only works if mIRC can ignore the line. It wouldn't have worked with things like the userhost exploit, for instance, which don't come from another nick.