1--TEST--
2Bug GH-12745 (http_build_query() default null argument for $arg_separator is implicitly coerced to string)
3--FILE--
4<?php
5
6$data = [
7    'hello' => 'world',
8    'foo' => 'bar',
9];
10
11var_dump(http_build_query(
12    $data,
13    encoding_type: PHP_QUERY_RFC3986
14));
15?>
16--EXPECT--
17string(19) "hello=world&foo=bar"
18