Remove plugin headers from drop-ins

[swissspidy]

When installing the plugin from WordPress.org, WordPress wrongly detects the drop-ins as the main plugin files because they contain a valid plugin header. That means the plugin can't be activated right away after installing.

On the "Installed Plugins" screen, it works as expected.

[JJJ]

Interesting.

I'd be more inclined to call this a bug in WordPress. Plugin folders shouldn't legitimately contain more than 1 header, and it should probably stop once it's found one. That way packages like this are possible, and drop-ins -- which support plugin headers -- can continue to have them.

I wonder if it's actually allowed/supported for a plugin's directory to have multiple. Hmm.

[swissspidy]

It's possible to have multiple plugin files in one folder, WordPress allows it. In the early days Jetpack "bundled" a few plugins, for example. I thought it's not allowed in the repository, but your plugin seems to prove me wrong.

Of course it's a bad practice, but, you know, back compat.

[swissspidy]

It's pretty weird. Normally, plugins in the same folder are all displayed in the plugin list table, here that doesn't seem to be the case. So it might indeed be a bug in WordPress. That would explain the behaviour (not working after install but working in the plugin list table).

I hope I'll find time to test this more…

Related: https://core.trac.wordpress.org/ticket/35145

[swissspidy]

@swissspidy can you confirm if this is still an issue with drop-ins being nested a second directory deep?

Can't really test since it's not yet on WordPress.org, but I had another look at core. The relevant code in wp_ajax_install_plugin() is as follows:

$api = plugins_api( 'plugin_information', array(
    'slug'   => sanitize_key( wp_unslash( $_POST['slug'] ) ),
    'fields' => array(
        'sections' => false,
    ),
) );

$install_status = install_plugin_install_status( $api );

$status['activateUrl'] = add_query_arg( array(
    '_wpnonce' => wp_create_nonce( 'activate-plugin_' . $install_status['file'] ),
    'action'   => 'activate',
    'plugin'   => $install_status['file'],
), network_admin_url( 'plugins.php' ) );

In install_plugin_install_status():

$installed_plugin = get_plugins('/' . $api->slug);
$key = array_keys( $installed_plugin );
$key = reset( $key ); // Use the first plugin regardless of the name, Could have issues for multiple-plugins in one directory if they share different version numbers

There it is!

[szepeviktor]

Please consider keeping a line comment: Spider-Cache advanced cache drop-in

[swissspidy]

Can't seem to reproduce this anymore when "shiny" installing & activating WP Spider Cache. 🤷‍♂️