Summary of Changes

PHP 7.2 disallows the use of the count() function on non countable items (arrays or objects implementing the Countable interface). We have places in our API where null values were being returned then pushed into a count() call, this PR addresses three uses found on a cursory click through a CMS install using PHP 7.2.0RC5.

Testing Instructions

To verify:

• Install Joomla without sample data then click to the login page. You get a countable warning coming from the Updater.php file by way of the plugin which checks for updates and sends an email notification triggering an update check. This is caused by properties in the CollectionAdapter class not being initialized as empty arrays and therefore when no updates are found the properties are still set as null versus being array.
• After logging in, the two articles modules will give a countable warning coming from the com_content articles model. This is caused by a state value not setting an appropriate default if the state value is null.
• Install Joomla with the testing sample data and navigate to the frontend "Single Contact" page. You get a countable warning coming from the similar tags module. This is caused by the module's helper method returning null in some conditions instead of simply returning an empty array.

Apply the patch and repeat these steps.

(If you do not reinstall before item 1, you will need to clear the update check timestamps for the plg_system_updatenotification plugin params and the Joomla! Core update site).

Expected result

Data is displayed without error.

Actual result

Errors as a result of trying to count a non-countable item.