Change return value of add_listmode() / add_listmode_ex(). This fixes

a bug when two servers merge, you could see +beI items being set that
already exist, if the timestamp or setter differed between servers.
Now they are updated but no +beI is shown.
https://bugs.unrealircd.org/view.php?id=5681

src/channel.c

@@ -242,12 +242,16 @@ int identical_ban(const char *one, const char *two)
 /** Add a listmode (+beI) with the specified banid to
  *  the specified channel. (Extended version with
  *  set by nick and set on timestamp)
+ * @retval	1	Added
+ * @retval	0	Updated
+ * @retval	-1	Ban list full
  */
 int add_listmode_ex(Ban **list, Client *client, Channel *channel, const char *banid, const char *setby, time_t seton)
 {
 	Ban *ban;
 	int cnt = 0, len;
 	int do_not_add = 0;
+	char isnew = 0;
 
 	//if (MyUser(client))
 	//	collapse(banid);
@@ -294,6 +298,7 @@ int add_listmode_ex(Ban **list, Client *client, Channel *channel, const char *ba
 		ban = make_ban();
 		ban->next = *list;
 		*list = ban;
+		isnew = 1;
 	}
 
 	if ((ban->when > 0) && (seton >= ban->when))
@@ -308,7 +313,7 @@ int add_listmode_ex(Ban **list, Client *client, Channel *channel, const char *ba
 	safe_strdup(ban->banstr, banid); /* cAsE may differ, use oldest version of it */
 	safe_strdup(ban->who, setby);
 	ban->when = seton;
-	return 0;
+	return isnew ? 1 : 0;
 }
 
 /** Add a listmode (+beI) with the specified banid to

src/modules/chanmodes/floodprot.c

@@ -1407,7 +1407,7 @@ int floodprot_can_send_to_channel(Client *client, Channel *channel, Membership *
 			} else {
 				snprintf(mask, sizeof(mask), "*!*@%s", GetHost(client));
 			}
-			if (add_listmode(&channel->banlist, &me, channel, mask) == 0)
+			if (add_listmode(&channel->banlist, &me, channel, mask) == 1)
 			{
 				mtags = NULL;
 				new_message(&me, NULL, &mtags);
@@ -1415,7 +1415,7 @@ int floodprot_can_send_to_channel(Client *client, Channel *channel, Membership *
 				sendto_channel(channel, &me, NULL, 0, 0, SEND_LOCAL, mtags,
 				    ":%s MODE %s +b %s", me.name, channel->name, mask);
 				free_message_tags(mtags);
-			} /* else.. ban list is full */
+			} /* else.. ban list is full or already exists */
 		}
 		mtags = NULL;
 		kick_user(NULL, channel, &me, client, errbuf);
@@ -1777,7 +1777,7 @@ int do_floodprot_action_alternative(Channel *channel, int what, FloodType *flood
 	         floodtype->alternative_ban_action);
 
 	/* Add the ban internally */
-	if (add_listmode(&channel->banlist, &me, channel, ban) == -1)
+	if (add_listmode(&channel->banlist, &me, channel, ban) != 1)
 		return 0; /* ban list full (or ban already exists) */
 
 	/* First the notice to the chanops */

src/modules/mode.c

@@ -593,10 +593,10 @@ const char *mode_ban_handler(Client *client, Channel *channel, const char *param
 		}
 	}
 
-	if ( (what == MODE_ADD && add_listmode(banlist, client, channel, tmpstr)) ||
+	if ( (what == MODE_ADD && (add_listmode(banlist, client, channel, tmpstr) != 1)) ||
 	     (what == MODE_DEL && del_listmode(banlist, channel, tmpstr)))
 	{
-		return NULL;	/* already exists */
+		return NULL;	/* ban to be added already exists, or ban to be deleted does not exist */
 	}
 
 	return tmpstr;

src/modules/sjoin.c

@@ -531,21 +531,21 @@ CMD_FUNC(cmd_sjoin)
 			/* Adding of list modes */
 			if (*item_modes == 'b')
 			{
-				if (add_listmode_ex(&channel->banlist, client, channel, item, setby, setat) != -1)
+				if (add_listmode_ex(&channel->banlist, client, channel, item, setby, setat) == 1)
 				{
 					Addit('b', item);
 				}
 			}
 			if (*item_modes == 'e')
 			{
-				if (add_listmode_ex(&channel->exlist, client, channel, item, setby, setat) != -1)
+				if (add_listmode_ex(&channel->exlist, client, channel, item, setby, setat) == 1)
 				{
 					Addit('e', item);
 				}
 			}
 			if (*item_modes == 'I')
 			{
-				if (add_listmode_ex(&channel->invexlist, client, channel, item, setby, setat) != -1)
+				if (add_listmode_ex(&channel->invexlist, client, channel, item, setby, setat) == 1)
 				{
 					Addit('I', item);
 				}