Ticket #50850: 50850.diff

wp-admin/includes/plugin.php

@@ -567 +567 @@
                 return false;
         }
 
-        $plugins = get_site_option( 'active_sitewide_plugins' );
-        if ( isset( $plugins[ $plugin ] ) ) {
+        $plugins = (array) get_site_option( 'active_sitewide_plugins', array() );
+        if ( in_array( $plugin, $plugins, true ) ) {
                 return true;
         }
 
@@ -1053 +1053 @@
         }
 
         if ( is_multisite() && current_user_can( 'manage_network_plugins' ) ) {
-                $network_plugins = (array) get_site_option( 'active_sitewide_plugins', array() );
-                $plugins         = array_merge( $plugins, array_keys( $network_plugins ) );
+                $network_plugins = get_site_option( 'active_sitewide_plugins', array() );
+                // Validate vartype: array.
+                if ( ! is_array( $network_plugins ) ) {
+                        update_option( 'active_sitewide_plugins', array() );
+                        $network_plugins = array();
+                }
+                $plugins = array_merge( $plugins, array_keys( $network_plugins ) );
         }
 
         if ( empty( $plugins ) ) {