1--TEST--
2Compound array assign with undefined variables
3--FILE--
4<?php
5$a[$b] += 1;
6var_dump($a);
7?>
8--EXPECTF--
9Warning: Undefined variable $a in %s on line %d
10
11Warning: Undefined variable $b in %s on line %d
12
13Warning: Undefined array key "" in %s on line %d
14array(1) {
15  [""]=>
16  int(1)
17}
18