nickserv: accept IDENTIFY [account] <password>

IDENTIFY now takes an optional leading account name, so logging into an
account whose name differs from your current nick works. Without it, the
account still defaults to the current nick as before.

modules/nickserv/nickserv.rs

@@ -39,12 +39,18 @@ impl Service for NickServ {
                     nick: from.nick.to_string(),
                 });
             }
-            Some("IDENTIFY") => {
+            Some("IDENTIFY") | Some("ID") => {
-                let Some(password) = args.get(1) else {
+                // IDENTIFY [account] <password> — the account defaults to the
-                    ctx.notice(me, from.uid, "Syntax: IDENTIFY <password>");
+                // current nick, so both the bare-password and account+password forms work.
-                    return;
+                let (account_name, password) = match (args.get(1), args.get(2)) {
+                    (Some(account), Some(password)) => (*account, *password),
+                    (Some(password), None) => (from.nick, *password),
+                    _ => {
+                        ctx.notice(me, from.uid, "Syntax: IDENTIFY [account] <password>");
+                        return;
+                    }
                 };
-                match db.authenticate(from.nick, password) {
+                match db.authenticate(account_name, password) {
                     Some(account) => {
                         // Already identified to this account: don't re-fire the login.
                         if from.account == Some(account) {
@@ -75,7 +81,7 @@ impl Service for NickServ {
             Some("HELP") => ctx.notice(
                 me,
                 from.uid,
-                "NickServ looks after your nickname. Commands: \x02REGISTER\x02 <password> [email], \x02IDENTIFY\x02 <password>, \x02LOGOUT\x02, \x02CERT\x02 ADD|DEL|LIST <password> [fingerprint].",
+                "NickServ looks after your nickname. Commands: \x02REGISTER\x02 <password> [email], \x02IDENTIFY\x02 [account] <password>, \x02LOGOUT\x02, \x02CERT\x02 ADD|DEL|LIST <password> [fingerprint].",
             ),
             Some(other) => ctx.notice(me, from.uid, format!("I don't know the command \x02{other}\x02. Try \x02HELP\x02.")),
             None => {}

src/engine/mod.rs

@@ -978,6 +978,25 @@ mod tests {
         assert!(out.iter().any(|a| matches!(a, NetAction::Metadata { key, value, .. } if key == "accountname" && value == "realnick")), "must log into the current nick's account: {out:?}");
     }
 
+    // IDENTIFY accepts the two-arg account+password form: log into a named
+    // account even when the current nick differs; a wrong password is refused.
+    #[test]
+    fn identify_two_arg_account_form() {
+        let mut e = engine_with("twoarg", "realacct", "sesame");
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAB".into(), nick: "someguest".into(), host: "host.example".into() });
+        let out = e.handle(NetEvent::Privmsg {
+            from: "000AAAAAB".into(), to: "42SAAAAAA".into(), text: "IDENTIFY realacct sesame".into(),
+        });
+        assert!(out.iter().any(|a| matches!(a, NetAction::Metadata { key, value, .. } if key == "accountname" && value == "realacct")), "two-arg identify logs into the named account: {out:?}");
+
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAC".into(), nick: "other".into(), host: "host.example".into() });
+        let bad = e.handle(NetEvent::Privmsg {
+            from: "000AAAAAC".into(), to: "42SAAAAAA".into(), text: "IDENTIFY realacct wrongpw".into(),
+        });
+        assert!(bad.iter().any(|a| matches!(a, NetAction::Notice { text, .. } if text.contains("Invalid password"))), "{bad:?}");
+        assert!(!bad.iter().any(|a| matches!(a, NetAction::Metadata { .. })), "wrong password must not log in: {bad:?}");
+    }
+
     // ChanServ: registration needs identification, INFO shows the founder, and
     // only the founder can drop.
     #[test]