Description:
------------
none

Test script:
---------------
<?php
$b = [0, 1, 2];

var_dump($b);
substr_replace("test", $b, "1");
var_dump($b);

Expected result:
----------------
array(3) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(2)
}
array(3) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(2)
}

Actual result:
--------------
array(3) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(2)
}
array(3) {
  [0]=>
  string(1) "0"
  [1]=>
  int(1)
  [2]=>
  int(2)
}
[Tue Dec 22 12:03:13 2015]  Script:  '/tmp/1.php'
/home/huixinchen/opensource/php-7.0/Zend/zend_string.h(121) :  Freeing 0x7FFFF8059D00 (32 bytes), script=/tmp/1.php
=== Total 1 memory leaks detected ===