MDL-45616 repositories: API changes to avoid serialized data in user input

Author: marinaglancy

repository/lib.php

@@ -1671,14 +1671,6 @@ public static function display_instances_list($context, $typename = null) {
     public function get_file_reference($source) {
         if ($source && $this->has_moodle_files()) {
             $params = @json_decode(base64_decode($source), true);
-            if (!$params && !in_array($this->get_typename(), array('recent', 'user', 'local', 'coursefiles'))) {
-                // IMPORTANT! Since default format for moodle files was changed in the minor release as a security fix
-                // we maintain an old code here in order not to break 3rd party repositories that deal
-                // with moodle files. Repositories are strongly encouraged to be upgraded, see MDL-45616.
-                // In Moodle 2.8 this fallback will be removed.
-                $params = file_storage::unpack_reference($source, true);
-                return file_storage::pack_reference($params);
-            }
             if (!is_array($params) || empty($params['contextid'])) {
                 throw new repository_exception('invalidparams', 'repository');
             }

repository/upgrade.txt

@@ -3,6 +3,12 @@ information provided here is intended especially for developers. Full
 details of the repository API are available on Moodle docs:
 http://docs.moodle.org/dev/Repository_API
 
+=== 2.8 ===
+
+* Repositories working with Moodle files must replace serialize() with json_encode() in the
+  attribute 'source' returned by get_listing(). If repository overrides file_is_accessible(),
+  get_file_reference() or get_file_source_info() they need to be changed too. See MDL-45616.
+
 === 2.6 ===
 
 * get_option() now always return null when the first parameter ($config) is not empty, and