pclzip and zero length files in PHP 8.x

[Jako]

xPDO 2.x has issues with zero length files in PHP 8.x. The same code works fine in PHP 7.x. The same issue may occur with xPDO 3.x.

PHP Fatal error:  Uncaught ValueError: fread(): Argument #2 ($length) must be greater than 0 in /…/core/xpdo/compression/pclzip.lib.php:2678

I am not sure why this issue occurs only in PHP 8.x, but creating a transport file with PHP 7.4 works well and not with PHP 8.1/8.2 during my tests when an empty file (.gitignore in my case) exists in a folder in a package. If the file has a length of 1 byte everything works well.

It is more of a guide as to why the issue is occurring and how it can be resolved.

[opengeek]

Why are you using pclzip with PHP 8? Do you have hosting that does not include the zip extension?

[opengeek]

Point being, I'd really love to get rid of the pclzip code.

[Jako]

I am using MAMP locally. For whatever reason this does not use the zip extension.

[Jako]

I can install the extension with https://documentation.mamp.info/en/MAMP-PRO-Mac/FAQ/PHP/Install-a-PHP-extension-using-PECL/ but this has to be done for AFAIK every different PHP version.

[opengeek]

Right. The problem is there is no PCLZIP version maintained any longer and it is not compatible with PHP 8. I have no interest in maintaining yet another project.

[Jako]

Before you drop it, PCLZIP currently only has issues with empty files in PHP 8.x in MODX.

[Jako]

Just to be sure. MAMP is compiled with ZIP support. Does it have to use PCLZIP then? Or is it just a wrong check that xPDO uses that part of code?

[modxcommunity]

This issue has been mentioned on MODX Community. There might be relevant details there:

https://community.modx.com/t/subject-issue-with-updating-extension-in-modx-3-0-5/8137/2