Reputation was synced correctly on IP basis (and thus the databases)

across servers if they differed, however the individual IP of users
was not updated until next add_scores() run. So, there would be an
up to 5 minute delay during which scores for individual users were
possibly too low, with all the effects that it could possibly have
nowadays such as restrict-commands, more stringent flood limits, etc.

If your servers are all linked all the time then you would not have
noticed this issue. It mostly matters if you are linking in a new
server or if the server has been delinked or out of order for days
or weeks.

doc/RELEASE-NOTES.md

@@ -89,6 +89,8 @@ about UnrealIRCd 6.
 * [`set::modes-on-join`](https://www.unrealircd.org/docs/Set_block#set::modes-on-join)
   did not work with `+f` + timed bans properly, eg `[3t#b1]:10`
 * Several log messages were missing some information.
+* Reputation syncing across servers had a small glitch. Fix is mostly
+  useful for servers that were not linked to the network for days or weeks.
 
 ### Changes:
 * Clarified that UnrealIRCd is licensed as "GPLv2 or later"

src/modules/reputation.c

@@ -918,6 +918,24 @@ static inline int is_reputation_expired(ReputationEntry *e)
 	return 0;
 }
 
+/** If the reputation changed (due to server syncing) then update the
+ * individual users reputation score as well.
+ */
+void reputation_changed_update_users(ReputationEntry *e)
+{
+	Client *client;
+
+	list_for_each_entry(client, &client_list, client_node)
+	{
+		if (client->ip && !strcmp(e->ip, client->ip))
+		{
+			/* With some (possibly unneeded) care to only go forward */
+			if (Reputation(client) < e->score)
+				Reputation(client) = e->score;
+		}
+	}
+}
+
 EVENT(delete_old_records)
 {
 	int i;
@@ -1279,6 +1297,7 @@ CMD_FUNC(reputation_server_cmd)
 			   log_data_integer("score", e->score));
 #endif
 		e->score = score;
+		reputation_changed_update_users(e);
 	}
 
 	/* If we don't have any entry for this IP, add it now. */
@@ -1296,6 +1315,7 @@ CMD_FUNC(reputation_server_cmd)
 		e->score = score;
 		e->last_seen = TStime();
 		add_reputation_entry(e);
+		reputation_changed_update_users(e);
 	}
 
 	/* Propagate to the non-client direction (score may be updated) */