Currently you can enter nearly everything into the TCP port configuration fields both in the global configuration and the configuration for the LDAP authentication plugin. These fields should accept only valid numbers in the range of 1 through 65535, they should have a reasonable default value if applicable and it should be possible to leave them empty if they are not required.

Initially this PR was an add-on PR for PR #11322 but since that other PR was closed in the meantime and the author suggested that someone else might continue I merged the changes from PR #11322 into this PR and added the configuration for the LDAP authentication plugin since it also contains a TCP port field.

Testing Instructions

Status Quo

• Open in the Joomla administration the global configuration form and select the "Server" tab
• Enable FTP such that the "FTP Port" field is shown
• Enter any text, e.g. "foo", into that field and press the "Save" button
• Check the value for the "$ftp_port" variable in configuration.php, it should be "foo"
• Check the value in the global configuration form, it should be "foo" too
• Clear the "FTP Port" field and press the "Save" button
• Now the "$ftp_port" variable in configuration.php and the "FTP Port" field should be empty again
• Enable Proxy such that the "Proxy Port" field is shown
• Repeat the above tests, the variable to check in configuration.php is "$proxy_port"
• Disable Proxy after these tests
• Enable sending mails if not enabled
• Switch the mailer to "SMTP" such that the "SMTP Port" field is shown
• Replace the value (probably "25") with any text, e.g. "bar" and press the "Save" button
• Check the value for the "$smtpport" variable in configuration.php, it should be "bar"
• Check the value in the global configuration form, it should be "bar" too
• Clear the "SMTP Port" field (when doing so the border should become red) and try to save the form
• The form is not saved, you have to enter a value in the "SMTP Port" field
• Enter the value found there initially (probably "25") into the field and press the "Save" button
• Saving should work now, check in the configuration.php file and in the global configuration form
• Leave the global configuration form by means of the "Save & Close" button
• Open Extensions -> Plugins and locate the "Authentication - LDAP" plugin
• Open the configuration for this plugin and locate the "Port" field
• The content in this field is probably "389"
• Repeat the above tests with the "Port" field
• Note that when you clear the field the default value "389" is automatically filled in
• Leave the plgin configuration by means of the "Save & Close" button

Change

• Now install this PR
• Check configuration.php: "$ftp_port" and "proxy_port" should be empty and "$smtpport" should be set
• Open in the Joomla administration the global configuration form and select the "Server" tab
• Enable FTP such that the "FTP Port" field is shown
• The field "FTP Port" should now look different, it contains the hint "21" you can increase and decrease the current value by clicking the "up" and "down" arrows at the right side of the field
• Enter any text, e.g. "foo", into that field, the border of the field is shown in red as long as the cursor is in that field
• Press the "Save" button
• Next you'll get a success message and the field again contains the hint "21"
• Check configuration.php: "$ftp_port" is still empty
• This behaviour is as expected: the browser doesn't send illegal values to the server, and since the "FTP Port" field is declared as numeric and the value "foo" is no number the browser sends an empty field to the server
• Enter an invalid port number in the "FTP Port" field, e.g. "99999" and press the "Save" button
• You'll get an error message because the value is not allowed, the "$ftp_port" variable in configuration.php has not been changed
• Enter a valid port number in the "FTP Port" field, e.g. "21" and press the "Save" button
• Check configuration.php: "$ftp_port" is now "21"
• The value "21" is also shown in the "FTP Port" field
• Clear the "FTP Port" field and press the "Save" button
• Enable Proxy such that the "Proxy Port" field is shown
• Repeat the above tests, the variable to check in configuration.php is "$proxy_port"
• Disable Proxy after these tests
• Repeat the above tests with the "SMTP Port" field, in doing so note that this field is required -> you must enter a valid number, e.g. "25" into that field
• Leave the global configuration form by means of the "Save & Close" button
• Open Extensions -> Plugins and locate the "Authentication - LDAP" plugin
• Open the configuration for this plugin and locate the "Port" field
• The content in this field is probably "389"
• Repeat the above tests with the "Port" field
• Note that when you clear the field the default value "389" is automatically filled in
• Leave the plgin configuration by means of the "Save & Close" button

Recipe for defining numeric fields

Currently most fields that shall accept only numeric values are defined as follows:

<field
        name="..."
        type="text"
        label="..."
        description="..."
        default="..."
        filter="integer"
        size="5"
/>

The "default" attribute might be missing if it is not appropriate for a field, the filter type given is sometimes "string" instead of "integer" and the "size" attribute sometimes has other values, e.g. "8".

When converting such a field into a truly numeric field (a field where the browser knows that it is numeric) one of the two following formats should be used.

Format (a) with a default value:

<field
        name="..."
        type="number"
        label="..."
        description="..."
        min="1"
        max="65535"
        default="..."
        validate="number"
        filter="integer"
        size="5"
/>

Format (b) without a default value, instead with a hint:

<field
        name="..."
        type="number"
        label="..."
        description="..."
        min="1"
        max="65535"
        hint="..."
        validate="number"
        filter="integer"
        size="5"
/>

Note that the "min" and "max" attributes are set in both formats appropriately for TCP port fields, change them as necessary for other purposes or remove either of them if not needed.