Fix logic for RRD and DHCP leases backup, and fix wording in the placeholder text. Fixes #6040

Author: jim-p

src/usr/local/www/system_advanced_misc.php

@@ -273,11 +273,19 @@
 		$config['system']['use_mfs_var_size'] = $_POST['use_mfs_var_size'];
 
 		if (isset($_POST['rrdbackup'])) {
-			$config['system']['rrdbackup'] = $_POST['rrdbackup'];
+			if (($_POST['rrdbackup'] > 0) && ($_POST['rrdbackup'] <= 24)) {
+				$config['system']['rrdbackup'] = intval($_POST['rrdbackup']);
+			} else {
+				unset($config['system']['rrdbackup']);
+			}
 			install_cron_job("/etc/rc.backup_rrd.sh", ($config['system']['rrdbackup'] > 0), $minute="0", "*/{$config['system']['rrdbackup']}");
 		}
 		if (isset($_POST['dhcpbackup'])) {
-			$config['system']['dhcpbackup'] = $_POST['dhcpbackup'];
+			if (($_POST['dhcpbackup'] > 0) && ($_POST['dhcpbackup'] <= 24)) {
+				$config['system']['dhcpbackup'] = intval($_POST['dhcpbackup']);
+			} else {
+				unset($config['system']['dhcpbackup']);
+			}
 			install_cron_job("/etc/rc.backup_dhcpleases.sh", ($config['system']['dhcpbackup'] > 0), $minute="0", "*/{$config['system']['dhcpbackup']}");
 		}
 
@@ -543,7 +551,7 @@
 	'Periodic RRD Backup',
 	'number',
 	$config['system']['rrdbackup'],
-	['min' => 1, 'max' => 24, 'placeholder' => 'frequency between 1 and 24 hours']
+	['min' => 0, 'max' => 24, 'placeholder' => 'Period between 1 and 24 hours']
 ))->setHelp('This will periodically backup the RRD data so '.
 	'it can be restored automatically on the next boot. Keep in mind that the more '.
 	'frequent the backup, the more writes will happen to the media.');
@@ -553,7 +561,7 @@
 	'Periodic DHCP Leases Backup',
 	'number',
 	$config['system']['dhcpbackup'],
-	['min' => 1, 'max' => 24, 'placeholder' => 'frequency between 1 and 24 hours']
+	['min' => 0, 'max' => 24, 'placeholder' => 'Period between 1 and 24 hours']
 ))->setHelp('This will periodically backup the DHCP leases so '.
 	'it can be restored automatically on the next boot. Keep in mind that the more '.
 	'frequent the backup, the more writes will happen to the media.');