Description:
------------
This bug is so old. I had reported it once, but couple of developers could not read carefully the description and closed it as bogus, still it is a bug.



Test script:
---------------
$o = new \stdClass(); 
$o->{123} = 456; 
$a = (array)$o; 
$a[123] = 777; 
var_dump($a);

Expected result:
----------------
array(1) {
  [123]=>
  int(777)
}

Actual result:
--------------
array(2) {
  ["123"]=>
  int(456)
  [123]=>
  int(777)
}