--TEST--
preg_replace_callback_array() errors
--FILE--
<?php

function b() {
    return "b";
}

// empty strings

var_dump(
    preg_replace_callback_array(
        [
            '/a/' => 'b',
            '' => function () {
                return 'ok';
            },
        ],
        'a'
    )
);

var_dump(
    preg_replace_callback_array(
        [
            '/a/' => 'b',
            null => function () {
                return 'ok';
            },
        ],
        'a'
    )
);

// backslashes

var_dump(
    preg_replace_callback_array(
        [
            '/a/' => 'b',
            "\\b\\" => function () {
                return 'ok';
            },
        ],
        'a'
    )
);

// alphanumeric delimiters

var_dump(
    preg_replace_callback_array(
        [
            '/a/' => 'b',
            'aba' => function () {
                return 'ok';
            },
        ],
        'a'
    )
);

var_dump(
    preg_replace_callback_array(
        [
            '/a/' => 'b',
            '1b1' => function () {
                return 'ok';
            },
        ],
        'a'
    )
);

// null character delimiter

var_dump(
    preg_replace_callback_array(
        [
            '/a/' => 'b',
            "\0b\0" => function () {
                return 'ok';
            },
        ],
        'a'
    )
);

?>
--EXPECTF--
Warning: preg_replace_callback_array(): Empty regular expression in %spreg_replace_callback_array_error.php on line %d
NULL

Warning: preg_replace_callback_array(): Empty regular expression in %spreg_replace_callback_array_error.php on line %d
NULL

Warning: preg_replace_callback_array(): Delimiter must not be alphanumeric, backslash, or NUL byte in %spreg_replace_callback_array_error.php on line %d
NULL

Warning: preg_replace_callback_array(): Delimiter must not be alphanumeric, backslash, or NUL byte in %spreg_replace_callback_array_error.php on line %d
NULL

Warning: preg_replace_callback_array(): Delimiter must not be alphanumeric, backslash, or NUL byte in %spreg_replace_callback_array_error.php on line %d
NULL

Warning: preg_replace_callback_array(): Delimiter must not be alphanumeric, backslash, or NUL byte in %spreg_replace_callback_array_error.php on line %d
NULL