Description:
------------
array_key_exists fails on arrays created by get_object_vars on Objects with numeric Propertie Names.
It works fine in the old PHP 5.3 enviroment.

Test script:
---------------
$json = '{"100308":1}';
$temp = json_decode($json);
$sub = get_object_vars($temp); // Error Array
var_dump($sub, array_key_exists('100308', $sub));

Expected result:
----------------
array(1) {
  [100308]=>
  int(1)
}
bool(true)

Actual result:
--------------
array(1) {
  ["100308"]=>
  int(1)
}
bool(false)