Ticket #20437: upgrader_base_dirs_filter.patch

wp-admin/includes/class-wp-upgrader.php

@@ -207 +207 @@
                         $source_files = array_keys( $wp_filesystem->dirlist($source) );
 
                 //Protection against deleting files in any important base directories.
-                if ( in_array( $destination, array(ABSPATH, WP_CONTENT_DIR, WP_PLUGIN_DIR, WP_CONTENT_DIR . '/themes') ) ) {
+                if ( in_array( $destination, apply_filters( 'upgrader_base_directories', array(ABSPATH, WP_CONTENT_DIR, WP_PLUGIN_DIR, WP_CONTENT_DIR . '/themes') ) ) ) {
                         $remote_destination = trailingslashit($remote_destination) . trailingslashit(basename($source));
                         $destination = trailingslashit($destination) . trailingslashit(basename($source));
                 }