1--TEST--
2Test empty arrays with first added index being negative
3--FILE--
4<?php
5
6$a = [];
7$a[-5] = "-5";
8$a[] = "after -5";
9
10var_dump($a);
11?>
12--EXPECT--
13array(2) {
14  [-5]=>
15  string(2) "-5"
16  [-4]=>
17  string(8) "after -5"
18}
19