Soe time ago, we fixed the config validator to accept revServer lines…

… without <domain>, however, there was another check at the point where this configuration is written intp dnsmasq.conf as users may have edited pihole.toml directly without going through the API (so, effectively, bypassing the validators). This last check still enforced <domain> which is relaxed herein

Signed-off-by: DL6ER <[email protected]>

src/config/dnsmasq_config.c

@@ -500,9 +500,9 @@ bool __attribute__((const)) write_dnsmasq_config(struct config *conf, bool test_
 			continue;
 		}
 
-		if(active == NULL || cidr == NULL || target == NULL || domain == NULL)
+		if(active == NULL || cidr == NULL || target == NULL)
 		{
-			log_err("Skipped invalid dns.revServers[%u]: %s", i, revServer->valuestring);
+			log_err("Skipped invalid dns.revServers[%u]: %s (not fully defined)", i, revServer->valuestring);
 			free(copy);
 			continue;
 		}
@@ -513,7 +513,7 @@ bool __attribute__((const)) write_dnsmasq_config(struct config *conf, bool test_
 
 		// If we have a reverse domain, we forward all queries to this domain to
 		// the same destination
-		if(strlen(domain) > 0)
+		if(domain != NULL && strlen(domain) > 0)
 		{
 			fprintf(pihole_conf, "server=/%s/%s\n", domain, target);