Steps to reproduce the issue

Set the name of a tinymce plugin in the "Custom Plugin" field of the "Editor - TinyMCE" configuration page of the admin ui.

Expected result

When an article is edited the specified tinymce extension should be loaded.

Actual result

When an article is edited the specified tinymce extension is not loaded.

System information (as much as possible)

In the PlgEditorTinymce class, the onDisplay function calls $levelParams->get('custom_plugin', '') to retrieve the names of custom plugins that the user wants tinymce to load. The value returned is empty. So, the extensions the user wants loaded, are not loaded.

Basically, the text the user typed into the plugin configuration is not making it to the code that creates the javascript to initialize tinymce.

Additional comments

A simple work around is to insert something like this

	$plugins[] = 'nameofplugin';

in the onDisplay function of the PlgEditorTinymce class.

A good plugin to use for testing is the "noneditable" plugin since it's already included with Joomla.

And of course, this will break when tinymce.php gets overwritten in a future update. I hope it gets fixed before then.