Steps to reproduce the issue

1. Install a joomla with Test English sample data.
2. Now go to backend and create a new tag (for example test) with no parent tag. You will see that the tag path assigned to the tag is wrong: red/test

I detected the issue trying to assign my new tag to any article. When writing test in the tags field the wrong path will be suggested.

This is caused because the ROOT tag already exists and then the insert on sample data is ignored. So the rgt value is never updated. We need to update the ROOT rgt value after inserting the other tags.

Expected result

A tag with no parent shouldn't have any parent in the path. In our example a test tag with no parent should have a test path.

System information (as much as possible)

Latest Joomla (v3.4) from staging branch.

$ php --version
PHP 5.5.9-1ubuntu4.6 (cli) (built: Feb 13 2015 19:17:11) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
    with Zend OPcache v7.0.3, Copyright (c) 1999-2014, by Zend Technologies

$ mysql --version
mysql  Ver 14.14 Distrib 5.5.41, for debian-linux-gnu (x86_64) using readline 6.3

Backward compatibility

This patch only affects to the sample data so it cannot break any existing site.

How to test patch

Apply the patch and then clean configuration.php contents to create a new installation with the Test English sample data. Then create again the test tag and see if the path value is correct.

Additional comments

My patches for postgreSQL and SQL server are blindly applied so ideally we should have someone testing them.