error_reporting() Sometimes Sets Bizarre Values

[miqrogroove]

Description

I'm having a strange problem with PHP 8.2.26 and 8.4.2 on a DreamHost server. I have a test case that gives a totally different result when I run it on the PHP sandbox at onlinephp.io, so I don't understand why this works in some environments but not others.

When setting the error reporting level to -1 the server is interpreting that as a large negative integer.

<?php
error_log('The default error reporting level is ' . error_reporting());
error_reporting(-1); // Report all errors
error_log('Top of file error reporting level is ' . error_reporting());
error_log('The correct level would be ' . E_ALL);

Output:

The default error reporting level is 22517
Top of file error reporting level is -10251
The correct level would be 32767

The reporting level is being set to -10251 which is not correct, and I'm not getting any error reports.

When I attempted to resolve this by switching to E_ALL, then I got this equally problematic situation:

error_reporting(E_ALL); // Report all errors.
error_log('Top of file error reporting level is ' . error_reporting());
error_log('The correct level would be ' . E_ALL);

Output:

Top of file error reporting level is 22517
The correct level would be 30719

Is there a bug here, or is this somehow specific to the server I'm using?

PHP Version

PHP 8.2.26 (cli) (built: Nov 21 2024 20:16:53) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.2.26, Copyright (c) Zend Technologies
    with Zend OPcache v8.2.26, Copyright (c), by Zend Technologies

Operating System

No response

[miqrogroove]

I checked two more hosting environments and could not reproduce the problem. This malfunction appears to be specific to DreamHost.

[miqrogroove]

Here is the latest test case for anyone else affected.

<?php
ini_set('error_log', 'error_log');
ini_set('display_errors', true);
echo '<pre>';
echo 'The error log file is ' . ini_get('error_log') . "\n";
echo 'The logging level is ' . ini_get('log_errors') . "\n";
echo 'The display level is ' . ini_get('display_errors') . "\n";
echo 'The default error reporting level is ' . error_reporting() . "\n";
error_reporting(-1); // Report all errors
echo 'After setting -1, error reporting level is ' . error_reporting() . "\n";
error_reporting(E_ALL); // Report all errors
echo 'After setting E_ALL, error reporting level is ' . error_reporting() . "\n";
echo 'The correct level would be ' . E_ALL . "\n";
echo 'The PHP version is ' . phpversion() . "\n";
echo $undefined;

Output:

The error log file is error_log
The logging level is 1
The display level is 1
The default error reporting level is 22517
After setting -1, error reporting level is -10251
After setting E_ALL, error reporting level is 22517
The correct level would be 30719
The PHP version is 8.4.2

By the way, 10251 is the two's complement of 22517 for a 15-bit computer. Someone at DreamHost is applying a corrupt bit mask to this function.