Ticket #17816: 17816.patch

wp-admin/includes/update-core.php

@@ -373 +373 @@
         $wp_filesystem->put_contents($maintenance_file, $maintenance_string, FS_CHMOD_FILE);
 
         // Copy new versions of WP files into place.
-        $result = _copy_dir($from . $distro, $to, array('wp-content') );
+        $result = _copy_dir($from . $distro, $to, apply_filters( 'update_core_skip_list', array('wp-content') ) );
 
         // Custom Content Directory needs updating now.
         // Copy Languages