Added new cyclic reference test

tests/026b.phpt

@@ -0,0 +1,67 @@
+--TEST--
+Cyclic array test 2
+--INI--
+report_memleaks=0
+--SKIPIF--
+<?php
+if(!extension_loaded('igbinary')) {
+ echo "skip no igbinary";
+}
+--FILE--
+<?php
+
+$a = array("foo" => &$b);
+$b = array(1, 2, $a);
+var_dump($a);
+
+/* all three statements below should produce same output however PHP stock
+ * unserialize/serialize produces different output (5.2.16). I consider this is
+ * a PHP bug. - Oleg Grenrus
+ */
+
+//$k = $a;
+//$k = unserialize(serialize($a));
+$k = igbinary_unserialize(igbinary_serialize($a));
+var_dump($k);
+
+$k["foo"][1] = "b";
+var_dump($k);
+
+?>
+--EXPECT--
+array(1) {
+ ["foo"]=>
+ &array(3) {
+ [0]=>
+ int(1)
+ [1]=>
+ int(2)
+ [2]=>
+ *RECURSION*
+ }
+}
+array(1) {
+ ["foo"]=>
+ &array(3) {
+ [0]=>
+ int(1)
+ [1]=>
+ int(2)
+ [2]=>
+ *RECURSION*
+ }
+}
+array(1) {
+ ["foo"]=>
+ &array(3) {
+ [0]=>
+ int(1)
+ [1]=>
+ string(1) "b"
+ [2]=>
+ array(1) {
+ ["foo"]=>
+ *RECURSION*
+ }
+ }
+}