Steps to reproduce the issue

Note: Do this test on a test system in order not to update a live site.

On a current staging, update Joomla! using the Joomla! update component with the installation method "Write files using FTP" and following custom URL:

http://test5.richard-fath.de/list_test4.xml

(The custom URL is necessary for being offered an update when already being on staging = 3.6.0-dev. The container behing it is a normal update package to current staging as it is now, 2016-05-05 17:36 CEST)

You have to enter correct acess information in the corresponding fields after having selected method "Write files using FTP", and in your global configuration, FTP also has to be switched on and be configured with the same account information.

Expected result

The update is started.

Actual result

The update start fails with message about invalid host or port.

System information (as much as possible)

Not really relevant.

Additional comments

The reason for the issue is the variables "$this->host" and "$this->port" being empty strings when function "ftp_connect" is called.

You can verify this by adding the following code line

error_log('Test 1: useSSL=' . $this->useSSL . ', host=' . $this->host . ', port=' . $this->port);

before the 2 occurances of the following code lines in file "administrator/components/com_joomlaupdate/restore.php":

if($this->useSSL) {
$this->handle = @ftp_ssl_connect($this->host, $this->port);
} else {
$this->handle = @ftp_connect($this->host, $this->port);
}

You will then see in your PHP error log (if logging to file is switched on in your PHP settings) that these variables are empty strings.

Before PR #9612 with the new functionality for the update component was merged, means on a 3.5.1 or older, this error was not visible, because the "direct write" method always has been used, regardless whether FTP method was chosen or not.

You can see this by adding following code to file administrator/components/com_joomlaupdate/controllers/update.php, function _applyCredentials(), at line 328:

JFactory::getApplication()->getUserStateFromRequest('com_joomlaupdate.method', 'method', 'direct', 'cmd');

This will make it use FTP mode, as it has been added to staging with PR #9612 , and then udpate will fail with invalid server name.

If you do not add this code on a 3.5.1 or older and use invalid FTP access information, e.g. invalid username, you will see that the update will be started, because FTP will not be used. I do not know how far this error goes back in history, but at least on a 3.4.8 I can confirm it.