Use IsLoggedIn() macro everywhere where possible.

Based on previous reports and patches from k4be in
https://github.com/unrealircd/unrealircd/pull/129

Looks much cleaner now.

This also filters out the edge case where user_account_login()
could have been called when a user transitioned from "not logged in"
to "unconfirmed account". It did not cause any issues AFAICT but
it is not really expected either.

src/modules/account-notify.c

@@ -70,7 +70,7 @@ int account_notify_account_login(Client *client, MessageTag *recv_mtags)
 				     CAP_ACCOUNT_NOTIFY, mtags,
 				     ":%s ACCOUNT %s",
 				     client->name,
-				     !isdigit(*client->user->svid) ? client->user->svid : "*");
+				     IsLoggedIn(client) ? client->user->svid : "*");
 	free_message_tags(mtags);
 	return 0;
 }

src/modules/account-tag.c

@@ -87,7 +87,7 @@ void mtag_add_account(Client *client, MessageTag *recv_mtags, MessageTag **mtag_
 {
 	MessageTag *m;
 
-	if (client && client->user && (*client->user->svid != '*') && !isdigit(*client->user->svid))
+	if (IsLoggedIn(client))
 	{
 		m = safe_alloc(sizeof(MessageTag));
 		safe_strdup(m->name, "account");

src/modules/chanmodes/delayjoin.c

@@ -221,7 +221,7 @@ void clear_user_invisible_announce(Channel *channel, Client *client, MessageTag
 
 	ircsnprintf(exjoinbuf, sizeof(exjoinbuf), ":%s!%s@%s JOIN %s %s :%s",
 		client->name, client->user->username, GetHost(client), channel->chname,
-		!isdigit(*client->user->svid) ? client->user->svid : "*",
+		IsLoggedIn(client) ? client->user->svid : "*",
 		client->info);
 
 	new_message_special(client, recv_mtags, &mtags, ":%s JOIN %s", client->name, channel->chname);
@@ -343,7 +343,7 @@ int moded_chanmode(Client *client, Channel *channel, MessageTag *recv_mtags, cha
 							sendto_one(user, mtags, ":%s!%s@%s JOIN %s %s :%s",
 							           i->client->name, i->client->user->username, GetHost(i->client),
 							           channel->chname,
-							           !isdigit(*i->client->user->svid) ? i->client->user->svid : "*",
+							           IsLoggedIn(i->client) ? i->client->user->svid : "*",
 							           i->client->info);
 						} else {
 							sendto_one(user, mtags, ":%s!%s@%s JOIN :%s", i->client->name, i->client->user->username, GetHost(i->client), channel->chname);

src/modules/join.c

@@ -198,7 +198,7 @@ void _send_join_to_local_users(Client *client, Channel *channel, MessageTag *mta
 
 	ircsnprintf(exjoinbuf, sizeof(exjoinbuf), ":%s!%s@%s JOIN %s %s :%s",
 		client->name, client->user->username, GetHost(client), channel->chname,
-		!isdigit(*client->user->svid) ? client->user->svid : "*",
+		IsLoggedIn(client) ? client->user->svid : "*",
 		client->info);
 
 	for (lp = channel->members; lp; lp = lp->next)
@@ -722,7 +722,7 @@ void _userhost_changed(Client *client)
 
 			ircsnprintf(exjoinbuf, sizeof(exjoinbuf), ":%s!%s@%s JOIN %s %s :%s",
 				client->name, client->user->username, GetHost(client), channel->chname,
-				!isdigit(*client->user->svid) ? client->user->svid : "*",
+				IsLoggedIn(client) ? client->user->svid : "*",
 				client->info);
 
 			modes = get_chmodes_for_user(client, flags);

src/modules/nick.c

@@ -689,7 +689,7 @@ nickkill2done:
 	if (IsDead(client))
 		return;
 
-	if (client->user->svid[0] != '0')
+	if (IsLoggedIn(client))
 	{
 		user_account_login(recv_mtags, client);
 		/* no need to check for kill upon user_account_login() here

src/modules/sasl.c

@@ -69,8 +69,9 @@ int sasl_account_login(Client *client, MessageTag *mtags)
 {
 	if (!MyConnect(client))
 		return 0;
+
 	/* Notify user */
-	if (client->user->svid[0] != '0')
+	if (IsLoggedIn(client))
 	{
 		sendnumeric(client, RPL_LOGGEDIN,
 			BadPtr(client->name) ? "*" : client->name,

src/modules/svsmode.c

@@ -406,8 +406,18 @@ void do_svsmode(Client *client, MessageTag *recv_mtags, int parc, char *parv[],
 			case 'd':
 				if (parv[3])
 				{
+					int was_logged_in = IsLoggedIn(target) ? 1 : 0;
 					strlcpy(target->user->svid, parv[3], sizeof(target->user->svid));
-					user_account_login(recv_mtags, target);
+					if (!was_logged_in && !IsLoggedIn(target))
+					{
+						/* We don't care about users going from not logged in
+						 * to not logged in, which is something that can happen
+						 * from 0 to 123456, eg from no account to unconfirmed account.
+						 */
+					} else {
+						/* LOGIN or LOGOUT (or account change) */
+						user_account_login(recv_mtags, target);
+					}
 					if (MyConnect(target) && IsDead(target))
 						return; /* was killed due to *LINE on ~a probably */
 				}

src/modules/tkl.c

@@ -4422,9 +4422,7 @@ void ban_target_to_tkl_layer(BanTarget ban_target, BanAction action, Client *cli
 
 	if (ban_target == BAN_TARGET_ACCOUNT)
 	{
-		if (client->user && client->user->svid &&
-		    strcmp(client->user->svid, "0") &&
-		    (*client->user->svid != ':'))
+		if (IsLoggedIn(client) && (*client->user->svid != ':'))
 		{
 			/* Place a ban on ~a:Accountname */
 			strlcpy(username, "~a:", sizeof(username));

src/modules/whois.c

@@ -328,7 +328,7 @@ CMD_FUNC(cmd_whois)
 			 * display services account name if it's actually a services account name and
 			 * not a legacy timestamp.  --nenolod
 			 */
-			if (!isdigit(*target->user->svid))
+			if (IsLoggedIn(target))
 				sendnumeric(client, RPL_WHOISLOGGEDIN, name, target->user->svid);
 
 			/*

src/modules/whox.c

@@ -426,8 +426,7 @@ static int do_match(Client *client, Client *acptr, char *mask, struct who_format
 		return 1;
 
 	/* match account */
-	if (IsMatch(fmt, WMATCH_ACCOUNT) && !BadPtr(acptr->user->svid) &&
-		!isdigit(*acptr->user->svid) && match_simple(mask, acptr->user->svid))
+	if (IsMatch(fmt, WMATCH_ACCOUNT) && IsLoggedIn(acptr) && match_simple(mask, acptr->user->svid))
 	{
 		return 1;
 	}
@@ -813,7 +812,7 @@ static void do_who(Client *client, Client *acptr, Channel *channel, struct who_f
 				(int)((MyUser(acptr) && !hide_idle_time(client, acptr)) ? (TStime() - acptr->local->last) : 0));
 		}
 		if (HasField(fmt, FIELD_ACCOUNT))
-			append_format(str, sizeof str, &pos, " %s", (!isdigit(*acptr->user->svid)) ? acptr->user->svid : "0");
+			append_format(str, sizeof str, &pos, " %s", IsLoggedIn(acptr) ? acptr->user->svid : "0");
 		if (HasField(fmt, FIELD_OPLEVEL))
 			append_format(str, sizeof str, &pos, " %s", (channel && is_skochanop(acptr, channel)) ? "999" : "n/a");
 		if (HasField(fmt, FIELD_REPUTATION))