Unexpected null pointer in Zend/zend_smart_str.h

[YuanchengJiang]

Description

The following code:

<?php
$cdata = new DOMText;
var_dump($GLOBALS);

Resulted in this output:

/php-src/Zend/zend_smart_str.h:177:41: runtime error: null pointer passed as argument 1, which is declared to never be null
/usr/include/string.h:408:33: note: nonnull attribute specified here
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /php-src/Zend/zend_smart_str.h:177:41 in 

PHP Version

PHP 8.4.0-dev

Operating System

ubuntu 22.04

[devnexen]

var_dump(new DOMText);

is enough to reproduce it.

[nielsdos]

Yeah this regressed when I optimized $wholeText. The previous code used xmlStrcat which implicitly checked for a NULL argument, but now it's a direct memcpy which you shouldn't pass null pointers to, although it won't result in a crash because memcpy doesn't do anything if the length is 0.