Merge pull request #2960 from bar/patch-2

count() and serialize() should be uniform.

src/Datasource/ResultSetDecorator.php

@@ -40,7 +40,7 @@ class ResultSetDecorator extends Collection implements Countable, Serializable,
  * @return integer
  */
 	public function count() {
-		return count(iterator_to_array($this));
+		return count($this->toArray());
 	}
 
 /**