Explicilty passing default value for escape in SplFileObject::fgetcsv changes outcome

Description

The following code:

<?php

$file = new SplFileObject('php://memory', 'rw+');

$file->fwrite("foo;bar;baz");
$file->seek(0);

$file->setCsvControl(';', "\n");

while (!$file->eof()) {
    $line = $file->fgetcsv(escape: '\\');
    var_dump($line);
}

Resulted in this output:

array(1) {
  [0]=>
  string(11) "foo;bar;baz"
}

But I expected this output instead:

array(3) {
  [0]=>
  string(3) "foo"
  [1]=>
  string(3) "bar"
  [2]=>
  string(3) "baz"
}

For context, I am currently working on migrating a codebase from 8.2 to 8.4, and thought the safest option to keep existing behavior for fgetcsv calls would be to explicitly provide the current value of the default parameter, considering it will change in the next major version. I understand WHY it was implemented like this, but it is still a weird outcome. Ideally, the paramters for the method fgetcsv should be nullable, and default to null instead, so that the behavior is consistent with the way user land PHP functions and methods with default values for parameters work.

PHP Version

PHP 8.4.16 (cli) (built: Jan 13 2026 01:36:09) (NTS)
Copyright (c) The PHP Group
Built by https://github.com/docker-library/php
Zend Engine v4.4.16, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.16, Copyright (c), by Zend Technologies

Operating System

No response

Comience en el punto de entrada SplFileObject::fgetcsv y reproduzca el ejemplo usando setCsvControl(';', "\n") con un valor de escape pasado explícitamente. Investigue si los parámetros nullable pueden hacer que los valores predeterminados omitidos y explícitos sean coherentes y, a continuación, verifique que el CSV se analice en los tres campos solicitados.