+/**
+ * Identifies equivalent security releases with a hardcoded list.
+ *
+ * Generally, only the latest minor version of Drupal 8 is supported. However,
+ * when security fixes are backported to an old branch, and the site owner
+ * updates to the release containing the backported fix, they should not
+ * see "Security update required!" again if the only other security releases
+ * are releases for the same advisories.
+ *
+ * @return string[]
+ * A list of security release numbers that are equivalent to this release
+ * (i.e. covered by the same advisory), for backported security fixes only.
+ *
+ * @todo This is a temporary fix to allow minor-version backports of security
+ * fixes to be shown as secure. It should not be included in the codebase of
+ * any release or branch other than such backports. Replace this with
+ * https://www.drupal.org/project/drupal/issues/2766491.
+ */
+function _update_equivalent_security_releases() {
+ switch (\Drupal::VERSION) {
+ case '8.4.5':
+ return ['8.5.0-rc1'];
+ case '8.4.6':
+ return ['8.5.1'];
+ }
+
+ return [];
+}
+