gzfile and readgzfile no longer identify corrupted gzip data

Description

Using this (invalid) gzip file: corrupt.txt.gz for testing below.

Just for completion: this is what happens using zcat/gzip - it can't decode it and thinks it's encrypted. It's not, it's just garbage.

$ zcat corrupt.txt.gz
gzip: corrupt.txt.gz is encrypted -- not supported

The following code:

<?php
var_dump(gzfile("corrupt.txt.gz"));

Resulted in this output:

array(2) {
  [0]=>
  string(8) "x��	U"
  [1]=>
  string(6) "I-.��"
}

But I expected this output instead:

array(0) {
}

Running the same code with PHP < 8.5.3 (including 8.5.2) will result in the expected empty array.

The same issue exists when using readgzfile(): all older versions will return -1 while 8.5.3 returns binary data.

PHP Version

PHP 8.5.3 (cli) (built: Feb 12 2026 16:29:14) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.5.3, Copyright (c) Zend Technologies
    with Xdebug v3.5.1, Copyright (c) 2002-2026, by Derick Rethans
    with Zend OPcache v8.5.3, Copyright (c), by Zend Technologies

Operating System

ArchLinux

Commencez par reproduire le cas fourni corrupt.txt.gz avec gzfile() et readgzfile() sur PHP 8.5.2 et 8.5.3. Suivez le traitement gzip utilisé par ces fonctions et comparez le résultat des données corrompues avec le tableau vide attendu et les valeurs de retour -1 ; c’est terminé lorsque les deux fonctions rejettent le flux invalide comme auparavant.