1--TEST--
2ReflectionParameter::getDefaultValueConstantName() should also work for parameters of internal functions.
3--FILE--
4<?php
5$class = new ReflectionClass('DateTime');
6$method = $class->getMethod('setTime');
7
8foreach ($method->getParameters() as $parameter) {
9    try {
10        var_dump($parameter->getDefaultValueConstantName());
11    } catch (ReflectionException $exception) {
12        echo $exception->getMessage() . "\n";
13    }
14}
15
16echo "----------\n";
17
18$class = new ReflectionClass('DateTimeZone');
19$method = $class->getMethod('getTransitions');
20
21foreach ($method->getParameters() as $parameter) {
22    try {
23        var_dump($parameter->getDefaultValueConstantName());
24    } catch (ReflectionException $exception) {
25        echo $exception->getMessage() . "\n";
26    }
27}
28
29echo "----------\n";
30
31$class = new ReflectionClass('DateTimeZone');
32$method = $class->getMethod('listIdentifiers');
33
34foreach ($method->getParameters() as $parameter) {
35    try {
36        var_dump($parameter->getDefaultValueConstantName());
37    } catch (ReflectionException $exception) {
38        echo $exception->getMessage() . "\n";
39    }
40}
41
42?>
43--EXPECT--
44Internal error: Failed to retrieve the default value
45Internal error: Failed to retrieve the default value
46NULL
47NULL
48----------
49string(11) "PHP_INT_MIN"
50string(11) "PHP_INT_MAX"
51----------
52string(17) "DateTimeZone::ALL"
53NULL
54