commit - 6e7e744cc6c3d378ac9bace41586e4f32f456551
commit + 90ea23ab4fe3032824e22eb59bee305f35c4aae7
blob - 07f16eb0489b8a959cddc6cf1205af6027b2310d
blob + 2230f36eda26804f10f2c0d6525353db83eb9367
--- doc/Modes.txt
+++ doc/Modes.txt
@@ -56,6 +56,7 @@ users to lists (e.g. "invite list", "ban list"), other
   m	0.3.0	Channel is moderated, only "voiced" users can send messages.
   M	20	Only registered users (and IRC Ops) can send messages.
   n	0.3.0	Channel doesn't allow messages of users not being members.
+  N     ??      Users can't change their nickname while on this channel.
   O	18	Only IRC operators are allowed to join this channel.
   P	0.5.0	Channel is "persistent".
   Q	20	Nobody can be kicked from the channel.
blob - 98ac0e7f5e07ead740eed5297eb8b45802b59b8d
blob + 35026e5587300d08ebb61f9bf9af3a9f99824475
--- src/ngircd/irc-login.c
+++ src/ngircd/irc-login.c
@@ -172,6 +172,7 @@ GLOBAL bool
 IRC_NICK( CLIENT *Client, REQUEST *Req )
 {
 	CLIENT *intr_c, *target, *c;
+	CHANNEL *chan;
 	char *nick, *user, *hostname, *modes, *info;
 	int token, hops;
 
@@ -259,6 +260,22 @@ IRC_NICK( CLIENT *Client, REQUEST *Req )
 				Client_SetType( Client, CLIENT_GOTNICK );
 		} else {
 			/* Nickname change */
+
+			/* Check that the user isn't on any channels set +N */
+			if(Client_Type(Client) == CLIENT_USER &&
+			   !Client_HasMode(Client, 'o')) {
+				chan = Channel_First();
+				while (chan) {
+					if(Channel_IsMemberOf(chan, Client) &&
+					   Channel_HasMode(chan, 'N'))
+						return IRC_WriteErrClient(Client,
+									  ERR_NONICKCHANGE_MSG,
+									  Client_ID(Client),
+									  Channel_Name(chan));
+					chan = Channel_Next(chan);
+				}
+			}
+
 			Change_Nick(Client, target, Req->argv[0],
 				    Client_Type(Client) == CLIENT_USER ? true : false);
 			IRC_SetPenalty(target, 2);
blob - 2f9225067a4aa503146c142c811ac224243052ed
blob + 99255df14a5433f60b3ad56e35f7e8f802175916
--- src/ngircd/irc-mode.c
+++ src/ngircd/irc-mode.c
@@ -580,6 +580,7 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Ori
 		case 'M': /* Only identified nicks can write */
 		case 'm': /* Moderated */
 		case 'n': /* Only members can write */
+		case 'N': /* Can't change nick while on this channel */
 		case 'Q': /* No kicks */
 		case 't': /* Topic locked */
 			if(is_oper || is_machine || is_owner ||
blob - 8a7215b42172464a3f77204225292760fb47af5c
blob + 4f1632b09270f7a1c8f3d032f13047fed7851350
--- src/ngircd/messages.h
+++ src/ngircd/messages.h
@@ -127,6 +127,7 @@
 #define ERR_USERONCHANNEL_MSG		"443 %s %s %s :is already on channel"
 #define ERR_SUMMONDISABLED_MSG		"445 %s :SUMMON has been disabled"
 #define ERR_USERSDISABLED_MSG		"446 %s :USERS has been disabled"
+#define ERR_NONICKCHANGE_MSG		"447 %s :Cannot change nickname while on %s(+N)"
 #define ERR_NOTREGISTERED_MSG		"451 %s :Connection not registered"
 #define ERR_NOTREGISTEREDSERVER_MSG	"451 %s :Connection not registered as server link"
 #define ERR_NEEDMOREPARAMS_MSG		"461 %s %s :Syntax error"