Joomla 3.5.1

Expected behavior

When you click button Discover in view
administrator/index.php?option=com_installer&view=discover
all entries in database table xy_extensions with state = -1 ("not installed yet") should be deleted before webspace is checked for not installed extensions.

Actual behavior

When a folder with not installed extension is removed from webspace after it was found with button Discover it's always displayed in view
administrator/index.php?option=com_installer&view=discover

Testing Instructions

• Create folder /plugins/content/discovertest/
• Create file /plugins/content/discovertest/discovertest.xml

<?xml version="1.0" encoding="utf-8"?>
<extension version="3.5" type="plugin" group="content" method="upgrade">
<name>discovertest</name>
<files>
<filename plugin="discovertest">discovertest.php</filename>
</files>
</extension>

• Backend: Goto administrator/index.php?option=com_installer&view=discover
• Click button Discover.
• New item in view/list: discovertest. Don't install!
• Have a look in database table xyz_extensions

• You'll see an entry (highest extension_id) with state -1 and name discovertest.

• Delete new folder above.

• Click button Discover.
• Nothing has changed in list of view and in database. Still an entry discovertest (that's not installable and not present anymore in webspace).

None of the methods discover() (libraries/cms/installer/[adapter] or com_installer itself) is calling a purge() method. All are just setting state = -1 but never remove them if outdated.