Add test for bug #75155

NEWS

@@ -20,6 +20,10 @@ PHP                                                                        NEWS
   . Fixed bug #74631 (PDO_PCO with PHP-FPM: OCI environment initialized
     before PHP-FPM sets it up). (Ingmar Runge)
 
+- SPL:
+  . Fixed bug #75155 (AppendIterator::append() is broken when appending another
+    AppendIterator). (Nikita)
+
 - Standard:
   . Fixed bug #75097 (gethostname fails if your host name is 64 chars long). (Andrea)
 

ext/spl/tests/bug75155.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Bug #75155: AppendIterator::append() is broken when appending another AppendIterator
+--FILE--
+<?php
+
+$array_a = new ArrayIterator(array('a', 'b', 'c'));
+$array_b = new ArrayIterator(array('d', 'e', 'f'));
+
+$iterator = new AppendIterator;
+$iterator->append($array_a);
+
+$iterator2 = new AppendIterator;
+$iterator2->append($iterator);
+$iterator2->append($array_b);
+
+foreach ($iterator2 as $current) {
+    echo $current;
+}
+
+?>
+--EXPECT--
+abcdef