MDL-61028 search: Clear search engine users cache after tests

search/classes/engine.php

@@ -139,6 +139,15 @@ abstract class engine {
         return self::$cachedusers[$userid];
     }
 
+    /**
+     * Clears the users cache.
+     *
+     * @return null
+     */
+    public static function clear_users_cache() {
+        self::$cachedusers = [];
+    }
+
     /**
      * Returns a search instance of the specified area checking internal caching.
      *

search/classes/manager.php

@@ -371,6 +371,7 @@ class manager {
         static::$instance = null;
 
         base_block::clear_static();
+        engine::clear_users_cache();
     }
 
     /**