Summary of Changes

Added missing $user variable declaration in administrator/modules/mod_submenu/tmpl/default.php

Testing Instructions

1. Edit administrator/components/com_content/presets/content.xml
2. Change the COM_CONTENT_MENUS_ARTICLE_MANAGER entry adding a quicktask-permission attribute, i.e. change it to read:

<menuitem
	title="COM_CONTENT_MENUS_ARTICLE_MANAGER"
	type="component"
	element="com_content"
	link="index.php?option=com_content&amp;view=articles"
	quicktask="index.php?option=com_content&amp;task=article.add"
	quicktask-title="COM_CONTENT_MENUS_NEW_ARTICLE"
	quicktask-permission="core.create;com_content"
/>

3. Go to the content dashboard (/administrator/index.php?option=com_cpanel&view=cpanel&dashboard=content)

Actual result BEFORE applying this Pull Request

The page breaks with an error: “Call to a member function authorise() on null”

Expected result AFTER applying this Pull Request

The page works.

Documentation Changes Required

None

Side note

This issue was discovered while trying to set up a dashboard with a custom preset for my own component. That is to say, it affects all core and third party extensions since it's a very obvious omission when the view template was copied from mod_menu to mod_submenu and subsequently refactored.

Also note that the static code analysis in PhpStorm also caught the problem when I opened the affected file.