+ /**
+ * Return true if this cached output object is for a different revision of
+ * the page.
+ *
+ * @todo We always return false if $this->getCacheRevisionId() is null;
+ * this prevents invalidating the whole parser cache when this change is
+ * deployed. Someday that should probably be changed.
+ *
+ * @since 1.23
+ * @param int $id the affected article's current revision id
+ * @return Boolean
+ */
+ public function isDifferentRevision( $id ) {
+ $cached = $this->getCacheRevisionId();
+ return $cached !== null && $id !== $cached;
+ }