PHP incorrectly closes file handles when used to replace STDIN/STDOUT/STDERR

Description

The following code:

<?php
  fclose(STDIN);
  fclose(STDOUT);
  fclose(STDERR);
  fopen('/dev/null', 'r');
  fopen('/dev/null', 'w');
  fopen('/dev/null', 'w');

  exec("dig +noall +answer -t ns -q 'www.google.com'", $out, $ret);
  file_put_contents('ret.txt', $ret . "\n");

Resulted in exec failing with the return code 134 as seen in ret.txt

PHP's garbage collection seems to have not taken into account that the file handles opened are now in use as stdin/stdout/stderr. Obviously this can be worked around by storing the result of fopen into some global vars, but IMO this is a bug.

PHP Version

PHP 8.2.6

Operating System

Debian 11

Empieza reproduciendo el ejemplo de PHP 8.2.6 en Debian 11, centrándote en la sustitución de STDIN, STDOUT y STDERR y en la posterior recolección de basura. Traza cómo se gestionan esos flujos estándar antes de que se ejecute exec. Se considera terminado cuando el comando deja de fallar con el código de retorno 134 cuando los handles de sustitución no se conservan en variables globales.