Test for bug 26737:

Protected and private variables are not saved on serialization
when a user defined __sleep is used.

tests/classes/bug26737.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Bug #26737 (Protected and private variables are not saved on serialization when a user defined __sleep is used)
+--FILE--
+<?php
+class foo
+{
+	private $private = 'private';
+	protected $protected = 'protected';
+	public $public = 'public';
+
+	public function __sleep()
+	{
+		return array('private', 'protected', 'public');
+	}
+}
+$foo = new foo();
+$data = serialize($foo);
+var_dump(str_replace("\0", '\0', $data));
+?>
+--EXPECT--
+string(114) "O:3:"foo":3:{s:12:"\0foo\0private";s:7:"private";s:12:"\0*\0protected";s:9:"protected";s:6:"public";s:6:"public";}"